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The Nanling metallogenic belt in South China is characterized by well-developed tungsten-tin mineralization related to multiple-aged granitoids. This belt is one of the 5 key prospecting and exploration areas among the 19 important metallogenic targets in China. Important progress has been made in recent years in understanding the Nanling granitoids and associated mineralization, and this paper introduces the latest major findings as follows: (1) there exists a series of Caledonian, Indosinian, and Yanshanian W-Sn-bearing granites; (2) the Sn-bearing Yanshanian granites in the Nanling Range form an NE-SW trending aluminous A-type granite belt that stretches over 350 km. The granites typically belong to the magnetite series, and dioritic micro-granular enclaves with mingling features are very common; (3) the Early Yanshanian Sn- and W-bearing granites possess different petrological and geochemical features to each other: most Sn-bearing granites are metaluminous to weakly peraluminous biotite (hornblende) granites, with zircon ɛ Hf( t) values of ca. −2 to −8, whereas most W-bearing granites are peraluminous two-mica granites or muscovite granites with ɛ Hf( t) values of ca. −8 to −12; (4) based on the petrology and geochemistry of the W-Sn-bearing granites, mineralogical studies have shown that common minerals such as titanite, magnetite, and biotite may be used as indicators for discriminating the mineralizing potential of the Sn-bearing granites. Similarly, W-bearing minerals such as wolframite may indicate the mineralizing potential of the W-bearing granites. Future studies should be focused on examining the internal relationships between the multiple-aged granites in composite bodies, the metallogenic peculiarities of multiple-aged W-Sn-bearing granites, the links between melt evolution and highly evolved ore-bearing felsic dykes, and the connections between granite domes and mineralization. [ABSTRACT FROM AUTHOR]

Based on comprehensive studies in petrography, petrofabric analysis and geochemistry, this paper describes a unique and rare laminated micritic ferruginous primary dolostone crystallized and precipitated from the alkaline hot brine under the conditions of the Mesozoic faulted lake basin. The main rock-forming mineral of this dolostone is ferruginous dolomite with a micritic structure. This dolomite mostly exhibits laminae of 0.1–1 mm thick and is often discovered with other minerals, such as albite, analcite, barite and dickite, which have at least two types of interbedded laminae. Petrogeochemistry reveals that this dolostone contains a large number of typomorphic elements of hydrothermal sedimentation, including Sb, Ba, Sr, Mn, and V. In addition, the LREE is in relatively high concentrations and possesses the typical REE distribution pattern with negative Eu anomaly. Oxygen isotope values (δ 18O PDB) range from 5.89‰ to 14.15‰ with an average of 9.69‰. The ratio of 87Sr/ 86Sr is between 0.711648 and 0.719546, with an average of 0.714718. These data indicate that the depositional environment is a stable, blocked, anoxic low-lying hot brine pool in the bottom of deep lake controlled by basement faults. The hydrothermal fluid is the alkaline hot brine formed by the combination of the infiltration lake water and mantle-derived magmatic water, consisting of many ions, including Ca 2+, Mg 2+ and Fe 2+. Under the driving flow power of magmatic heat, gravity and compaction, the hydrothermal fluid overcame the overburden pressure and hydrostatic pressure of the lake water body, and boiled to explosion, and then the explosion shattered the original laminated micritic ferruginous primary dolostone near the vent and then formed a new type of dolostone called shattered “hydroexplosion breccias”. In the low-lying, unperturbed hot brine pool, far from the vent, the laminated micritic ferruginous primary dolostone was quickly crystallized and chemicals precipitated from the hydrotherm. This study of special rocks contributes to research into the causes of the formation of lacustrine carbonate rocks and dolostone. In particular, it provides new examples and research insights for future studies of the lacustrine dolomite from the similar Mesozoic and Cenozoic basins in China. [ABSTRACT FROM AUTHOR]

This paper explores the influence of the local meteoric conditions, the overlying soil on the concentrations of Ca, Mg, and Sr, and the ratios of Mg/Ca, Sr/Ca, and Mg/Sr in soil infiltrating water (SIW). An in situ monitoring program was carried out above the Furong Cave throughout 2010 to collect data on SIW, monthly temperature and rainfall, and the geochemical composition and granularity of soils. The discharge of SIW responded quickly to the local rainfall, and its residence time was the primary factor affecting the Ca, Mg, and Sr content of the SIW. The high concentrations of Ca, Mg, and Sr in the SIW during April should be attributed primarily to the prolonged residence of SIW in the soil during the local dry seasons of winter and early spring. The maximum Mg/Sr ratio also occurred in April. The ratio of Mg/Ca in SIW is positively correlated with prolonged residence time and with high temperatures, which do not strongly affect the ratio of Sr/Ca. The Mg/Ca ratio was lowest when the Sr/Ca ratio was highest because plant metabolism increased the absorption of Ca and Mg, but not Sr, and also because higher temperatures enhanced the dissolution of Mg more than that of Sr. These different responses of Mg and Sr to temperature increases resulted in high Mg/Sr ratios during July and August. [ABSTRACT FROM AUTHOR]

Global climate change and its possible ecological consequences have become the focused issue (IPCC, 2007; Mann et al., 2008; Ding et al., 2009). The Holocene contains the analogous characteristic of future climatic change and the continuous agriculture activity, providing the ideal “similar pattern” for studying the climate change and human adaption and impact in the future. Based on the recent studies of stalagmite, ice core, ocean, and lake etc., the paper introduces the new progress in the Holocene climate and agriculture research in China as follows: (1) Discuss the variability, amplitude, and unstable characteristic of climate, as well as the abrupt events and mechanisms of climate. (2) Analyze the botanical index records for studying the early agriculture. (3) Review the agricultural origin, expanding, and development. (4) Reveal the style and intensity of early agriculture and understand the agricultural impact and adaption to the environmental changes. (5) Introduce ongoing research projects in China and emphasize the significance of increasing the dating precision and the indicative effectiveness of proxies. (6) Realize how the ecosystem and environmental factors respond to the increasing temperature process, understand how the human adapt to the rapid climate change, and provide the scientific basis for assessing the effects of climate change and the human adaption in the future. [ABSTRACT FROM AUTHOR]

China has developed an airborne gravimetry system based on SINS/DGPS named SGA-WZ, the first system in which a strapdown inertial navigation system (SINS) has been used for airborne gravimetry in China. This gravity measurement system consists of a strap-down inertial navigation system and a differential global positioning system (DGPS). In April 2010, a flight test was carried out in Shandong Province of China to test the accuracy of this system. The test was designed to assess the repeatability and accuracy of the system. Two repeated flights and six grid flights were made. The flying altitude was about 400 m. The average flying speed was about 60 m/s, which corresponds to a spatial resolution of 4.8 km when using 160-s cutoff low-pass filter. This paper describes the data processing of the system. The evaluation of the internal precision is based on repeated flights and differences in crossover points. Gravity results in this test from the repeated flight lines show that the repeatability of the repeat lines is 1.6 mGal with a spatial resolution of 4.8 km, and the internal precision of grid flight data is 3.2 mGal with a spatial resolution of 4.8 km. There are some systematic errors in the gravity results, which can be modeled using trigonometric function. After the systematic errors are compensated, the precision of grid flight data can be better than 1 mGal. [ABSTRACT FROM AUTHOR]

This paper aims at exploring the tectonic characteristics of the South China Continent (SCC) and extracting the universal tectonic rules from these characteristics, to help enrich the plate tectonic theory and better understand the continental dynamic system. For this purpose, here we conduct a multi-disciplinary investigation and combine it with the previous studies to reassess the tectonics and evolution of SCC and propose that the tectonic framework of the continent comprises two blocks, three types of tectonic units, four deformation systems, and four evolutionary stages with distinctive mechanism and tectonic characteristics since the Neoproterozoic. The four evolutionary stages are: (1) The amalgamation and break-up of the Neoproterozoic plates, typically the intracontinental rifting. (2) The early Paleozoic and Mesozoic intracontinental orogeny confined by plate tectonics, forming two composite tectonic domains. (3) The parallel operation of the Yangtze cratonization and intracontinental orogeny, and multi-phase reactivation of the Yangtze craton. (4) The association and differentiation evolution of plate tectonics and intracontinental tectonics, and the dynamic characteristics under the Meso-Cenozoic modern global plate tectonic regime. [ABSTRACT FROM AUTHOR]

High abundant sulfur-containing steroids were identified and detected in saturate hydrocarbon fractions of heavy oil with a high sulfur content in the Jinxian Sag, Bohai Bay Basin, North China. These sulfur-containing steroids were structurally merged into the D-ring of steroid nucleus with thiophene ring and/or combined into the C-22 in the side-chain. Based on the previous reports of sulfur-containing steroids with methylthio-teroids and intra-molecular form, four formation mechanisms of sulfur-containing steroids and diagenetic pathway of steroids under S-rich conditions were proposed in this paper according to the double bond positions in the sterene compounds. Hydrogenation and sulfurization both occurred in the diagenetic processes of olefinic bond in the side-chain of steroids: abiogenic chemical hydrogenation of HS and HS leads to the formation of regular steranes; a successful sulfurization process leads to the formation of the side-chain sulfur-containing steroids whereas unsuccessful cyclization and/or sulfurization result in the generation of short-chain steranes. This kind of mechanism of hydrogenation/sulfurization of side-chain olefinic bond provides a potential genesis clue for the occurrence of high abundance of short-chain steranes (higher than the common regular steroids, phytane and n-alkanes) in S-rich heavy oils and source rocks in the Jinxian Sag, Bohai Bay Basin, North China. [ABSTRACT FROM AUTHOR]

The leaf area index ( LAI) is a critical biophysical variable that describes canopy geometric structures and growth conditions. It is also an important input parameter for climate, energy and carbon cycle models. The scaling effect of the LAI has always been of concern. Considering the effects of the clumping indices on the BRDF models of discrete canopies, an effective LAI is defined. The effective LAI has the same function of describing the leaf density as does the traditional LAI. Therefore, our study was based on the effective LAI. The spatial scaling effect of discrete canopies significantly differed from that of continuous canopies. Based on the directional second-derivative method of effective LAI retrieval, the mechanism responsible for the spatial scaling effect of the discrete-canopy LAI is discussed and a scaling transformation formula for the effective LAI is suggested in this paper. Theoretical analysis shows that the mean values of effective LAIs retrieved from high-resolution pixels were always equal to or larger than the effective LAIs retrieved from corresponding coarse-resolution pixels. Both the conclusions and the scaling transformation formula were validated with airborne hyperspectral remote sensing imagery obtained in Huailai County, Zhangjiakou, Hebei Province, China. The scaling transformation formula agreed well with the effective LAI retrieved from hyperspectral remote sensing imagery. [ABSTRACT FROM AUTHOR]

Modern palms are diverse and widespread in the tropics and subtropics, especially the tropical rainforests. However, most fossil palm records have been reported from regions of relatively higher latitude. In this paper seven species of coryphoid palm from the Eocene Changchang Basin of Hainan Island of South China are reported. These are Sabalites asymmetricus sp. nov., S. robustus sp. nov., S. tenufolius sp. nov., S. szei Guo, S. changchagnensis Guo, Livistona sp., and Amesoneuron sp. According to leaf morphological characteristics, they can be classified as members of the subfamily Coryphoideae. In extant flora of Hainan Island, only three species of Livistona have costapalmate leaves. These palm fossils indicate that, during the Eocene, flora in Hainan Island included a diversity of coryphoid palms, which have some bearings on the reconstruction of the palaeoclimate of South China. [ABSTRACT FROM AUTHOR]

Submicron aerosols (PM) in Beijing were studied using an Aerodyne aerosol mass spectrometer (AMS) from January to October 2008. This paper presents seasonal variations of different chemical components (sulfate, nitrate, ammonium, chloride and organics) and size distributions of PM. Results show that mass concentration of PM was highest in summer, and lowest in autumn. Organics represented the dominant species in all seasons, accounting for 36%-58% of PM, and their concentrations were highest in winter. Concentrations of inorganic components, sulfate, nitrate, and ammonium were highest in summer. Based on principal component analysis, organics were deconvolved and quantified as hydrocarbon-like and oxygenated organic aerosol (HOA and OOA, respectively). HOA was highest in winter, accounting for about 70% of organics. However, OOA was highest in summer, and had lower values in autumn and winter. A similar diurnal pattern of various components was observed, which is higher at nighttime and lower during daytime. HOA increased more dramatically than other species between 17:00 and 21:00 and peaked at noon, which could be related to cooking emissions. OOA, sulfate, nitrate, ammonium and chloride varied with the same trend. Their concentrations increased with solar radiation from 9:00 to 13:00, and declined with weakening solar radiation. Size distributions of all species showed apparent peaks in the range 500-600 nm. Size distributions of organics were much broader than other species, particularly in autumn and winter. Distributions of sulfate, nitrate and ammonium had similar patterns, broadening in winter. Contributions of different species were size-dependent; the finer the particle, the greater the contribution of organics. Organics represented more than 60% of particles smaller than 200 nm, contributing 50% to PM in winter. In spring and summer, HOA was the dominant organic fraction for particles smaller than 200 nm, while OOA contributed more to particles larger than 300 nm. In winter, HOA contributed more than OOA to all PM particles. [ABSTRACT FROM AUTHOR]

The irrigated areas in the northern region of China are important food production areas. Therefore, studies on the variability of the carbon balance in these agro-ecosystems are fundamental for the management of carbon sequestration. This paper simulated the long-term variability of the carbon balance in a typical irrigated area along the lower Yellow River from 1984 to 2006, using a process-based ecosystem model called the Simple Biosphere Model, version 2. The mean annual gross primary production (GPP), mean annual net assimilation rate (NAR), mean annual soil respiration ( R), and mean annual net ecosystem exchange (NEE) were 1733, 1642, 1304, and −338 g C m a, respectively. A significant increasing trend in the seasonal total NAR during the wheat growing season, and a significant decreasing trend in the seasonal total NAR during the maize growing season were detected. However, no significant trend was found in the annual NAR, R, and NEE. The average carbon sequestration was 1.93 Tg C a when the grain harvest was not taken into account, and the carbon sequestration amount during the maize season was higher than that during the wheat season. However, the agro-ecosystem was a weak carbon source with a value of 0.23 Tg C a, when the carbon in the grain was assumed emitted into the atmosphere. [ABSTRACT FROM AUTHOR]

Corals are comparatively abundant in the upper member of the Baiyun'an Formation (upper Aeronian to lowerest Telychian, Llandovery, Silurian) of Huaying, eastern Sichuan Province, Southwest China. Three coral associations have been recognized, i.e., in ascending order, the Mesofavosites Association, the Dentilasma Association, and the Paraceriaster Association. The Mesofavosites Association occurs at horizons indicating a shallow and high-energy environment. It is dominated by large favositids accompanied by a few broken pieces of halysitids and small solitary rugose corals. The Dentilasma Association has a pretty high coral diversity, dominated by the solitary rugose coral Dentilasma meitanense, together with some subordinative heliolitids and favositids. The sedimentary evidence shows that this association might live in a quiet and nutritive shallow water environment. The Paraceriaster Association yields in the grayish green calcareous mudstone indicating a comparatively deep water environment. Systematically it contains abundant fasciculate Paraceriaster micropora and a few favositids. The distinction among these three coral associations shows that corals could adopt different adaptive strategies under different environments, which provide some new data for the investigation on the ecology of Silurian corals and further study on the 'Lower Red Beds'. [ABSTRACT FROM AUTHOR]

Thermal evolution of source rocks and dynamic sealing evolution of cap rocks are both subjected to tectonic evolution. The marine sequences in South China have experienced superposed structural deformation from multiple tectonic events. To investigate the effectiveness of preservation conditions, it is of great importance to understand the controls of key tectonic events on the dynamic evolution of cap rocks. This paper discusses the controls of Late Jurassic-Early Cretaceous (J-K) tectonic event on source and cap rocks in marine sequences in South China based on the relationships between J-K tectonic event and the burial history types of the marine sequences, the hydrocarbon generation processes of marine source rocks, the sealing evolution of cap rocks, the preservation of hydrocarbon accumulations, and the destruction of paleo-oil pools. The study has the following findings. In the continuously subsiding and deeply buried areas during the J-K period, marine source rocks had been generating hydrocarbons for over a long period of time and hydrocarbon generation ended relatively late. At the same time, the sealing capacity of the overburden cap rocks had been constantly strengthened so that hydrocarbons could be preserved. In the areas which suffered compressional deformation, folding and thrusting, uplifting and denudation in J-K, the burial history was characterized by an early uplifting and the hydrocarbon generation by marine source rocks ended (or suspended) during the J-K period. The sealing capacity of the cap rocks was weakened or even vanished. Thus the conditions for preserving the hydrocarbon accumulations were destroyed. The continuously subsiding and deeply buried areas during the J-K period are the strategic precincts of the petroleum exploration in marine sequences in South China. [ABSTRACT FROM AUTHOR]

This paper deals with the backscatter coefficients known as sigma0 at Ku band and C band based on the GDR-M (Merged Geophysical Data Record) of TOPEX/Poseidon (T/P) through Jan. 1993 to Dec. 2004 over land surface of China. After smoothing and interpolating the backscatter coefficients for both bands, we achieve the 5′×5′ grid data and the time series of backscatter coefficients in 12 years. The spatial distribution of sigma0 over typical areas (wetland, desert, mountainous area, agriculture base, etc.) of Chinese territory is analyzed and discussed. The fast Fourier transformation (FFT) is used to detect the cycles of seasonal variations of sigma0 time series and gives that the annual period is the major cycle. Meanwhile a semiannual period is also found in some places. We use the least squares method on both periods and find that the amplitude of annual period is obviously greater than that of semi-annual period. The relationship among the anomalousness of time series, variations of environment and climate change, and the serious natural calamity (flood, drought) is also discussed. Data of topography slope extracted from SRTM are used to do correlation analysis with the backscatter coefficients in parts of China to quantify the impact of slope on backscatter coefficients in Ku and C bands, and the results show that they all have a negative correlation but the magnitudes are different in different places with different coverages. Such as the area of Liaoning and Jilin has the maximum correlation −0.56, the Taklimakan Desert has the minimum correlation −0.11, and the other places commonly have correlations in (−0.3, −0.5). [ABSTRACT FROM AUTHOR]

This paper reports petrographic, mineral chemical, olivine oxygen isotopic, and whole-rock geochemical data for wehrlite xenoliths from the Early Cretaceous Tietonggou high-Mg diorites in western Shandong Province, in the eastern part of the North China Craton (NCC), and describes the origin of these wehrlites and the processes that affected the deep lithospheric mantle in this area. Wehrlite xenoliths are rounded and vary in size between 3 cm × 4 cm × 5 cm and 3 cm × 2 cm × 1 cm. Olivine within these xenoliths occurs as an isolated residual phase within clinopyroxene, has Fo contents between 89 and 91, and contains between 1414 and 3629 ppm Ni, similar to the values of olivine from peridotite xenoliths in the Cenozoic basalts of eastern China, but lower than the values of olivine from harzburgite xenoliths in the Early Cretaceous high-Mg diorites in western Shandong. In situ oxygen isotope analysis yielded δO values of olivine from (6.03±0.33)‰ to (6.82±0.35)‰, averaging (6.5±0.4)‰; this is higher than typical mantle-derived olivine ((5.2±0.3)‰). Compared with clinopyroxenes from peridotite xenoliths in the Late Cretaceous and Cenozoic basalts, clinopyroxenes in the wehrlites contain relatively low concentrations of NaO, TiO, and AlO, high concentrations of CaO, and higher Mg (91.2-94.1) and Ti/Eu ratios (2082-2845), being similar in composition to clinopyroxenes within harzburgite xenoliths in the Early Cretaceous high-Mg diorites. Clinopyroxenes from wehrlite xenoliths are characterized by low total REE abundance, enrichment in light REEs, and depletion in high field strength elements such as Nb, Ta, Zr, and Hf. Moreover, the Sr/Sr, Nd/Nd, and Os/Os (125 Ma) ratios of these wehrlites vary from 0.70596 to 0.70737, 0.512181 to 0.512416, and 0.12661 to 0.57650, respectively. These data suggest that these wehrlite xenoliths were formed by modification of the lithospheric mantle by melts derived from recycled continental crust. [ABSTRACT FROM AUTHOR]

The Chengjiang Formation is the earliest continental clastic deposit after the Jinning Orogeny in central Yunnan Province, and therefore its accurate depositional age is significant for understanding the formation and evolution of the Neoproterozoic rift basins in southern China. However, hampered by accuracy of the dating technique, the existing age data for the Chengjiang Formation are not very reliable. A large number of magmatic zircons were obtained from the tuff interbed in the lower part of the Chengjiang Formation in Jinyang area and the bottom part of the Chengjiang Formation in Dongchuan area, central Yunnan Province, and high-precision SHRIMP U-Pb dating was carried out on these zircons. The results show that the weighted mean Pb/U ages are 797.8±8.2 and 803.1±8.7 Ma respectively. In combination with related geological evidence, it has been demonstrated that the bottom boundary age of the Chengjiang Formation should be 800±5 Ma, whereas the top boundary age could be ca 725 Ma. By synthetically analyzing the latest age data for the relevant strata, it has been confirmed that the Chengjiang Formation should be correlated with the Suxiong Formation and the Kaijianqiao Formation in western Sichuan Province, the Liantuo Formation in the middle and lower Yangtze, the Hongchicun Formation and the Shangshu Formation in northern Zhejiang Province, the Puling Formation in southern Anhui Province, the Luokedong Formation and the Majianqiao Formation in northwestern Jiangxi Province, the Wuqiangxi Formation in northwestern Hunan Province, the Fanzhao Formation and the Qingshuijiang Formation in southeastern Guizhou Province, and the Sanmenjie Formation and the Gongdong Formation in northern Guangxi Province. Sedimentary cycle analysis shows that the sedimentary filling sequence of the Neoproterozoic rift basins in southern China can be divided into four cycles. Among them, Cycle II began at ca. 800 Ma, accompanied by intensive tectonic-thermal events. The zircon U-Pb ages from the bottom of the Chengjiang Formation reported in this paper indicate that the Neoproterozoic Kangdian rift subbasin probably started to develop at ca. 800 Ma and therefore missed Cycle I of the Neoproterozoic sedimentary filling sequence in southern China. [ABSTRACT FROM AUTHOR]

Many well-preserved silicified megalodontids found from the Jiapila Formation of the Upper Triassic in western China show great variations in the amorphous teeth and the massive hinge plate, making the internal molds vary greatly in size and shape. Thus, the internal molds of megalodontids do not always provide reliable taxonomic characters. As a result, about 3/4 of the 132 species and 6 of 9 genera of Triassic Megalodontidae erected on the basis of internal molds have to be revised. The revised definitions of genera Neomegalodon, Triadomegalodon, and Conchodon are given in this paper. [ABSTRACT FROM AUTHOR]

High-precision (±0.1 ppm) and high-frequency (hourly averaged) in situ measurements of atmospheric carbon dioxide (CO) were made for the first time from August 2005 to July 2007 at Yanbian, China using a non-dispersive Infrared (NDIR) analyzer with National Oceanic and Atmospheric Administration/Earth System Research Laboratory (NOAA/ESRL) standards. The results of these measurements are presented in this paper and are used to investigate the regional representativeness of regional background data at Yanbian and determine the CO emission source regions in Northeast Asia. The phase of the monthly variations at Yanbian reflects the special regional characteristics, which were overall in excellent agreement with other observatories in the middle-to-high latitudes in the Northern Hemisphere. Applying a hybrid receptor model to the regional emission source events in cold period (November-April), we estimated the distribution of the major CO emissions in the northeast Asia. The results indicated that the strongest potential emission areas contributing to Yanbian are the Beijing & Tianjin metropolitan areas, southwestern part of Shandong Province including Jinan, and Vladivostok. The results of this study reveal the usefulness of in situ CO measurements at Yanbian in establishing the scientific foundation for monitoring the large CO emission areas in northern China and Russia. Continued monitoring of CO at Yanbian within a regional network should provide significant contributions to both understanding the global/regional carbon cycle and constraining 'top-down' emissions in Northeast Asia. [ABSTRACT FROM AUTHOR]

This paper presents a synthetic U-Pb and Hf isotopic study of zircons and a whole-rock geochemical study on diabase swarms that were emplaced into the Proterozoic formations in the Xuzhou-Huaibei area, the southeast margin of North China Craton. Zircons from the diabase dykes display weak oscillatory zoning in the cathodoluminescence (CL) images and show high Th/U ratios (0.91-6.90), both of which are typical of a magmatic origin. The SHRIMP and Q-ICP-MS U-Pb zircon dating results indicate that the diabase swarms were emplaced at ca. 890 Ma. Hf isotopic analysis on these zircons gives ɛ( t) values ranging from 2.26 to 14.74 and Hf model age t and t ranging from 843 to 1321 Ma and from 808 to 1779 Ma, respectively. Geochemically, the diabase swarms are characterized by a relative enrichment in LREE and LILE (Rb, Ba and La), a comparative enrichment in Cr and Ni, but a slight depletement in HFSE (Th, Nb, Ta, Zr and Hf). They are plotted in the within-plate tholeiite series on the tectonic discrimination diagrams. Taken together, these geochemical and isotopic data suggest that the primary magmas to form the diabase dykes in the Xuzhou-Huaibei area could have been derived from a transitional mantle in the Mesoproterozoic, and were most probably emplaced under a continental margin extensional setting at ca. 890 Ma. The results of this study demonstrate that the Neoproterozoic (800-900 Ma)magmatism was not restricted to the Yangtze Block, but also occurred at the southeast margin of the North China Craton. [ABSTRACT FROM AUTHOR]

The Erlitou site is located at Yanshi City, Henan Province. This site is a large settlement site of Erlitou culture, and it is dated to 3800-3500 a BP. Five kinds of domestic animals, i.e., dogs, pigs, sheep, goats, and cattle were found from the site. In this paper, two problems have emerged in studies involving the estimation of local isotope levels and the distinction of migrants from locals. Tooth enamel samples from 17 domestic animals individuals were analyzed for strontium isotope ratio (Sr/Sr), by the thermal ionization mass spectrometry, including 10 pigs, 5 sheep and 2 cattle. The results show that the mean Sr/Sr ratios of 10 pigs enamel samples were 0.712078, Based on the local strontium isotopes ratio range determined by the mean Sr/Sr ratios ±2 σ of 10 pig enamel samples (0.712256-0.711900), we found that five sheep and one cattle from the Erlitou site fell well outside the local strontium isotopes ratio range and were considered to be non-local. [ABSTRACT FROM AUTHOR]

Polychaete serpulids are globally distributed tubeworms mostly in marine environments from Late Triassic to modern time. These calcareous tubeworms could be rock-forming, reef-building, or a principal fouling organism in harbor and bays. Carbonates of the Paleogene Kalatar Formation in southwest Tarim Basin yield abundant serpulid fossils, which, together with oyster fossils, constitute the characteristic fossil assemblage of the Kalatar Formation. Other common fossils include bivalves, gastropods, ostracods, echinoderms, and bryozoans. Lithologies that yielded serpulid fossils are characterized by micritic bioclastic limestone, sandy limestone, and shelly limestone, indicating a semi-restricted to open shallow marine environment with medium to low water energy. The research data about serpulids and their fossil materials from China are relatively rare. Based on the studies of fossils taxonomy, community palaeoecology, and fossil taphonomy, this paper analyzed and studied the types, occurrence, distribution, and morphological characteristics of serpulids and their palaeoecological features in the Kalatar Formation. Two serpulid community compositions were recognized in the Kalatar Formation, including a rock-forming Ditrupa community and a cluster-growth Propomatoceros community. The Ditrupa community was distributed in coastal environment of the west Kunlun piedmont, lived on sandy hard substrates with little mud, and rarely occurred in lagoon and tidal settings. The Propomatoceros community occurred in offshore middle carbonate ramp in the piedmont of the south Tianshan Mountains and in offshore shelf in the piedmont of the west Kunlun Mountains. According to the analysis on the host-rock lithologies, preservation and symbionts, it is inferred that serpulids in the Kalatar Formation grew on the oyster shell or other hard substrate, and they did not form reefs or bioherms. [ABSTRACT FROM AUTHOR]

The salt beds of the Middle-Lower Cambrian are widespread in the middle-west parts of the Central Uplift and adjacent areas, the Tarim Basin. This paper presents the results of seismic interpretation and drilling data analysis, which discovered that the salt beds were formed in an old geologic age, deeply buried, with relatively small scaled flowing and gathering and uneven distribution. As the regional detachment layers, the salt sequences considerably control the structural deformation of the up-salt Paleozoic, forming a series of hydrocarbon traps. In due course, the salt beds of the Middle-Lower Cambrian provide excellent cap rocks and trap conditions; thus the value of exploring hydrocabon reservoir in the target strata of the sub-salt Sinian-Cambrian is greatly increased. Research has shown that the salt-related structures of the Middle-Lower Cambrian in the area mainly exist in the form of salt pillow, salt roller, up-salt anticline, salt diapir, assemblage of the salt arch and up-salt fault-block, assemblage of basement fault and salt anticline, assemblage of the basement fault-block and salt dome, assemblage of salt detachment and fault-related fold, and assemblage of basement fault-block, salt arch and up-salt imbricated thrusts. The evolution and deformation mechanisms of the salt-related structures are controlled largely by basement faulting, compressional shortening, plastic flowing and gathering, superstratum gravitation, and up-salt faulting and detaching. They are distributed in rows or belts along basement faults or fault block belts. [ABSTRACT FROM AUTHOR]

The Altyn Tagh Fault and the Altyn Mountain define respectively the tectonic and geographical northern edges of the Tibetan Plateau, and figure prominently in the growth and rising mechanism of the plateau. The rhombus-shaped Altyn Mountain has long been thought to have an intimate relation with the Altyn Tagh Fault; however, its formation mechanism remains unclear and debatable. In this paper, we focus on the EW-trending uplifts in the Altyn Mountain, and investigated three Cenozoic sedimentary sections in the vicinity of the EW-trending uplifts located along the southern side of the central segment of the Altyn Tagh Fault. Magnetostratigraphy and pollen analysis were used to constrain ages of the sediments. Clast composition of conglomerate and paleocurrents obtained from clast imbrications were applied to determine the provenance. We also established a geological section parallel to the Altyn Tagh Fault on sedimentary facies across the northwestern Qaidam Basin. The results indicate that these en-echelon EW-trending uplifts formed as early as ca. 36 Ma and were preferred to be under the control of basal shear of the Altyn Tagh Fault in the middle-lower crust, symbolizing the early uplift of the Altyn Mountain during the Cenozoic. Left-slip along the Altyn Tagh Fault occurring during the Miocene and afterwards displaced and altered these uplifts, shaping the Altyn Mountain to its present fabric. [ABSTRACT FROM AUTHOR]

Historical records and archaeological remains indicate that the Chinese agricultural economy changed significantly from the Warring States (475-221 BC) to Han Dynasties (206 BC-220 AD), i.e., from rice-millet based agriculture to rice-millet-wheat based agriculture. However, the variation of human diets and the inner relationship between human diets and the agricultural transition during this period remain poorly understood. In this paper, the C and N stable isotopes from human and animal bones at the Shenmingpu site (SMPS), Xichuan County, Henan Province were analyzed. If some outliers (M34, M36, M102) were excluded, the mean δC value ((−16.7±0.8)‰, n=15) of humans in Han Dynasties was dramatically lower than that in the Warring States ((−12.7±0.8)‰, n=14), indicating that the cultivation of rice and wheat, especially wheat, had been more widely popularized in Han Dynasties. Meanwhile, the range of δN values of humans (6.6‰-9.3‰) in Han Dynasties was narrower than that of the Warring States (6.2‰-10.4‰), suggesting that the animal protein resources in human foods during Han Dynasties were more concentrated. The transition of human diets and the close relationship with the change of agricultural economy in SMPS were due to more stable society, the carryout of new agricultural policies, and the emergence of new agricultural tools in Han Dynasties [ABSTRACT FROM AUTHOR]

Marine red beds occur frequently in China through geological time. Despite their complex environments, the red beds are found in three depositional settings: 1) oceanic, deep water, as in the Upper Cretaceous of southern Tibet; 2) outer shelf, deeper water, as in the Lower-Middle Ordovician of South China; and 3) inner shelf, shallow water, as in the Silurian and Triassic in South China. The Silurian marine red beds are recurrent in the lower Telychian, upper Telychian, and upper Ludlow. This paper is to document the marine nature of the lower Telychian red beds (LRBs) in the Upper Yangtze Region and to discuss the spatial and temporal distribution of the LRBs and their depositional environments. The LRBs are best developed on the north side of the Cathaysian Oldland, which can be interpreted as the source area. It is inferred that they were deposited during a marine regression, characterized by the lack of upwelling, low nutrition and organic productivity with a decrease of biodiversity and a high rate of sedimentation. The iron-rich sediments may have been transported by rivers on the oldland into the Upper Yangtze Sea, as rates of deposition were rapid enough to counteract normal reducing effect around sediment-water interface. The LRBs are different from the off-shore, deeper water red beds of lower Telychian in Avalonia and Baltica and further from the oceanic, deep water red beds of Upper Cretaceous in southern Tibet chiefly in palaeogeographic settings, biotic assemblages and marine environments. [ABSTRACT FROM AUTHOR]

This paper investigates the important scientific problem of river regulation strategies in the lower reaches of the Yellow River, and discusses the 'geo-basis' of river regulation. The concept of a geo-basis to river regulation in the lower Yellow River was discussed in terms of subsidence and sedimentation features of the river plain; channel features, erosion characteristics of the Loess Plateau and storm-flood features of the middle and lower reaches. The geographic features of the lower Yellow River have gradually changed since the Holocene but there has been no fundamental change. Based on an analysis of the geo-attributes of the lower reaches of the Yellow River, several conclusions on its river regulation were made. The release of sediment should be the first measure of river regulation because of deposition in the lower reaches. The river channels should be provided with adequate space for wandering in the lower reaches. The tail river should be also provided with necessary wandering space because of weak marine dynamics in the estuary area and changes in the delta. Because the erosion environment of the Loess Plateau will not fundamentally change, river harnessing of the middle reaches should focus on improving the plateau morphology, which can be done by reducing the fragmentation of terrain and building a planation surface. Ecoremediation should focus on converting farmland to grassland. There may be extreme floods in the future, as has occurred previously, thus an extreme flood defense system should be considered for the lower reaches. A periodic law for regulation in the Yellow River is discussed. We also discuss how the current use of the lower reaches of the Yellow River is unsustainable and it is urgent to research artificial rechanneling and the creation of new flow paths for the lower reaches. [ABSTRACT FROM AUTHOR]

Little is known about the surface energy balance problem for a complex underlying surface. Taking data from the Loess Plateau Land-surface Processes Experiment (LOPEX) and investigating the characteristics of the surface energy balance over a complex underlying surface, this paper calculates the soil heat storage and vertical sensible heat advection, analyzes their contributions to the surface energy imbalance, and discusses the mechanism by which the vertical velocity and temperature gradient in the surface layer affect the vertical sensible heat advection transfer. We found that the vertical velocity in the surface layer provides the necessary dynamic power for vertical sensible heat advection, and a relatively strong temperature gradient is the energy source generating vertical sensible heat advection. Under an ascending condition, the effect of vertical sensible heat advection on the surface energy budget is more obvious. It is also found that when the soil heat storage term and the vertical sensible heat advection term are added to the energy balance equation, the imbalance significantly improves. The peak of average diurnal residuals decreases from 125.1 to 41.5 W m, the daily average absolute value of residuals falls from 59.0 to 26.4 W m, and the surface energy balance closure increases from 78.4% to 94.0%. [ABSTRACT FROM AUTHOR]

Up to now, all analysis of the distribution of water vapor over the Taklimakan desert area only depends on limited ground measurements and radio soundings setting mostly on the outer margin area. This paper establishes an approach to retrieve the water vapor over the desert at high temporal and spatial resolutions by the use of FY2C geostationary satellite split-window channels in cooperation with ground-based GPS water vapor measurement. Results show that the water vapor distribution over the Taklimakan desert is affected highly by topography and surface properties. The outer margin area has generally more water vapor than the inner area. Over the outer margin area, the western part has more water vapor than the eastern part, and the northern part has more than the southern part. The driest area lies to the south of Tazhong, east of Hotan River, and extended to the south boundary of the desert. Similar to elsewhere, water vapor over the desert area shows diurnal, monthly, seasonal and annual variations even at the driest inner area of the desert. In summer, the water vapor is transported from west to east over a long distance along the westerlies at a height between 700-400 hPa and with the average speed of 50 km h. [ABSTRACT FROM AUTHOR]

Terrestrial ecosystems may act as a source or a sink for the atmospheric greenhouse gases, carbon dioxide (CO), methane (CH), and nitrous oxide (NO), depending on land use and management. This paper reviews the literature on carbon, CH, and NO fluxes from terrestrial ecosystems in China, and analyzes its national greenhouse gas budget. Carbon storage in biomass and soils in Chinese terrestrial ecosystems decreased in the past 300 years, due to deforestation and expansion of cultivated land, and reached a minimum in the late 1970s. Since then, carbon storage has increased at an estimated rate of 0.19 to 0.26 Pg C yr, mainly owing to reforestation and afforestation. CH emission from natural wetlands decreased from 6.65 Tg CH yr in 1990 to 5.71 Tg CH yr in 2000 owing to the decrease in wetland area. CH emission from flooded rice fields was 7.41 Tg CH yr. At the same time, aerobic soils took up atmospheric CH at a rate of 2.56 Tg CH yr. Nitrous oxide emission from forestlands, grasslands, and farmlands was positively correlated with precipitation at a national scale, and the emission rate was positively correlated with the CH uptake rate of forestlands and grasslands ( P<0.01). Natural NO sources were estimated to be 419 Gg N yr and anthropogenic sources (from farmlands) to be 292 to 476.3 Gg N yr, with a mean of 372.6 Gg N yr. The integrated budget of greenhouse gasses indicates that Chinese terrestrial ecosystems act as a small net sink for global warming potential (GWP), ranging from 0.04 to 0.32 Pg CO-eq yr, in a striking contrast to terrestrial ecosystems globally, which are a source of 2.75 to 6.78 Pg CO-eq yr. The ratios of anthropogenic to natural sources of CH and NO are much larger in Chinese terrestrial ecosystems than they are in global averages, reflecting greater human disturbance of terrestrial ecosystems in China. [ABSTRACT FROM AUTHOR]

More than ten thousands of bone fragments were recovered from the Lingjing site, Henan Province during 2005 and 2006. In this paper, through the quantification and statistical analyses of the skeletal elements of the two predominant species in this assemblage, aurochs ( Bos primigenius) and horse ( Equus caballus), the differential influences and weights of a variety of taphonomic agencies in the formation of the assemblage are assessed respectively. Compared to the natural agencies, hominid hunting and the subsequent disarticulation, slaughtering, and their transport of the bone elements of the prey species are the main factors accounting for the formation of the present assemblage. More importantly, this study initiatively identifies hominid's differential treatment of the bones of aurochs and horse in the Paleolithic record of East Asia and demonstrably suggests that hominids at the site have already practiced sophisticated hunting techniques and subsistence strategies and may be quite familiar with the ecological and anatomical characteristics and nutritional values of the large-sized prey animals and can accordingly take different processing and handling strategies at the hunting site. [ABSTRACT FROM AUTHOR]

Although convection embedded in stratiform cloud is often disordered, it is ordered under certain weather conditions. In particular, there are two forms of ordered convection: embedded convection with a ladder-like pattern and that with a parallel pattern. However, there is little literature regarding these patterns. Because stratiform clouds with embedded convection are major objects for weather-modification studies, it is important to explore the formation/development and characteristic precipitation of embedded convection from the perspective of cloud and precipitation physics. In this paper, using observation data, we simulate a large-scale precipitation event in China for July 19-21, 2007, employing the mesoscale Weather Research and Forecasting (WRF) model (V2.2). The rainfall-related clouds are analyzed through simulation, with particular focus being given to the genesis of embedded convection, the precipitation and microphysical properties. The results show that the WRF model can simulate features of this kind of nephsystem, indicating a close relationship between convection genesis and the 500 hPa trough and low-level convergence line. In such a favorable weather situation, there are two ordered patterns of embedded convection in the nephsystem, one being a group of convection centers arranged at different altitudes in a ladder-like manner and the other being a group of convection centers with a parallel pattern. In the first case, rainfall also has a ladder feature, with precipitation being highest for the top convection and reducing to the base convection. This implies that the higher the convection develops, the more active the microphysics in warm- and cold-cloud processes is, leading to greater precipitation; i.e. rainfall in a ladder-like distribution. In the second case, rainfall decreases step by step from south to north, with the precipitation depending strongly on the cloud-water content therein. The two patterns of embedded convection and their precipitation features and microphysics are intensively studied from a new point of view. [ABSTRACT FROM AUTHOR]

Hsianghualite (CaLi[BeSiO]F, I23) is the first new mineral discovered in China in 1958 and is very precious due to its rare occurrence in the Earth. Few studies have reported about hsianghualite during these years. The authors measured the complex morphology of hsianghualite and found a twin structure in hsianghualite crystal by electron backscattered diffraction (EBSD) technique. The pole figures were used to analyze the twin relationship. The twin law of hsianghualite is the twin plane {110}. This twin law is the same as that proposed by crystallographic theoretic analysis in the previous work. EBSD experimental study verified our theoretic analysis of the twin structure in the previous work. The twin structure in hsianghualite has never been reported since the discovery of this mineral in 1958. [ABSTRACT FROM AUTHOR]

The occurrence of rice high-temperature damage (HTD) has increased with global warming. Cultivation of rice is seriously affected by the HTD in the middle and lower reaches of the Yangtze River, which directly affects food security in this region and in the whole of China. It is important to monitor and assess crop HTD using satellite remote sensing information. This paper reviews the recent development of monitoring rice HTD using optical remote sensing information. It includes the use of optical remote sensing information to obtain the regional spatial distribution of high temperatures, mixed-surface temperature retrieval for rice fields based on mixed decomposition information, the development of field and thermal infrared testing and modeling, and the satellite/ground-based remote sensing coupled method for monitoring rice HTD. Finally, the prospects for monitoring crop HTD based on remote sensing information are summarized. [ABSTRACT FROM AUTHOR]

This paper reports petrological and geochemical features and zircon U-Pb age of plagiogranite from the Hongliugou-Lapeiquan ophiolitic mélange belt in the northern Altyn Tagh. The zircon U-Pb dating results yield a mean U/Pb age of 512.1 ± 1.5 Ma, representing an emplacement time of the plagiogranites in the Middle Cambrian. The plagiogranites are interpreted to have derived from anatexis of hydrated amphibolites by ductile shearing during transports of the oceanic crust. Thus it is believed that the formation age of such type of plagiogranite was coeval to or slightly younger than the spreading of the Hongliugou-Lapeiquan limited oceanic basin. The new results from the plagiogranites suggest that an oceanic basin existed in the northern Altyn area during the Middle Cambrian. [ABSTRACT FROM AUTHOR]

Composite borehole profiling combined with trenching is an effective way to acquire evidence of past ruptures of buried active faults. In this study, three composite borehole profiles and a large-scale trench excavation were carried out across the surface rupture zone of the 1976 M7.8 Tangshan earthquake. The following three major conclusions have been reached. (1) The surface rupture zone of the 1976 earthquake extends more than 47 km long to the south of Tangshan city, passing to the west of Sunjialou, to Daodi town in Fengnan County, to Xihe in Fengnan County. (2) The surface rupture zone is divided into south and north branches. The north branch has mainly right-lateral strike-slip motion, and the vertical displacement of the surface is up on the west and down on the east. On the other hand, the vertical displacement of the south branch is up on the east and down on the west, accompanied by some right-lateral slip. Such a faulting style cannot be explained by the movement of a single normal or reverse fault, but is consistent with the vertical displacement field induced by the right-lateral strike-slip of the fault belt. The drilling and trenching data from this study verify that such activity continued through the Late Quaternary on the Tangshan Fault. (3) The fault planes exhumed by trenching and the dislocations of strata revealed by the boreholes indicate that multiple faulting events occurred on the Tangshan Fault in the Late Quaternary. The timing of three ruptures prior to the 1976 earthquake was 7.61-8.13, >14.57, and 24.21-26.57 ka BP. Counting the earthquake of 1976, the recurrence interval of the four strong events is about 6.7 to 10.8 ka. On one of the three borehole profiles, the Niumaku profile, nine faulting events were detected since 75.18 ka BP with an average interval of 8.4 ka. In addition, this paper also discusses the difference between the Late Quaternary sedimentary environments to the north and south of Tangshan city based on stratum dating. [ABSTRACT FROM AUTHOR]

The Yangtze continental nucleus in South China is situated in the Huangling-Shennongjia area in western Hubei Province. It comprises the early Precambrian crystalline basement and generally successive Proterozoic to Phanerozoic sedimentary covers. This paper reports a comprehensive Nd isotope study of fine-grained sedimentary rocks from the regional Mesoproterozoic to early Paleozoic strata. The Nd model ages display a V-shaped variation from ∼2.5-2.8 Ga during the late Mesoproterozoic through ∼1.5-1.7 Ga during the Neoproterozoic Nanhua Period to ∼1.8-2.1 Ga during the Paleozoic Ordovician, with corresponding ɛ( t) ranges of −11 to −14, −1.1 to −5.3, and −7.9 to −9.9, respectively. This evolutionary trend broadly resembles those documented in the sedimentary strata along the southeastern margin of the Yangtze Craton and within the Jiangnan orogenic belt, indicating that the whole South China block underwent a mantle-input related tectono-magmatic event at ∼0.8 Ga or earlier. However, the Huangling-Shennongjia area is discriminated from the other two regions by highly variable model ages (∼1.5-2.7 Ga) and ɛ( t) values (1.38-−12.0) of the early Mesoproterozoic strata. Combined with the Archean model ages of the late Mesoproterozoic strata, it is suggested that the Mesoproterozoic sedimentary provenance of the Yangtze continental nucleus was distinct from that of the southeastern Yangtze Craton, likely indicative of an intervening aulacogen (or rift zone) or oceanic basin. In addition, the high comparability in Neoproterozoic to Paleozoic Nd isotope stratigraphy between the Yangtze Craton and the Jiangnan orogenic belt infers that the whole South China block had shared the same sedimentary basin and provenance since the Yangtze-Cathaysia welding at ∼0.9 Ga. Thus, it is proposed that the Yangtze Craton had comprised a collage of micro-continents during the pre-Neoproterozoic until the Rodinia assemblage when the primitive South China block was formed. [ABSTRACT FROM AUTHOR]

This paper reports LA-ICP-MS zircon U-Pb ages and REE compositions on detrital zircons (Type 1) and hydrothermal zircons (Type 2) from low-metasedimentary rocks in the Mesoproterozoic Gaoyuzhuang Formation, Pingquan area, Hebei Province that provide important constraints on the tectonic evolution along the northern margin of the North China Block. The detrital zircons are characterized by an oscillatory magmatic core, surrounded by a narrow structureless rim in CL images. They yield Pb/Pb ages ranging from 1703 to 2543 Ma with two age peaks at 2473 and 1794 Ma, which is consistent with the Neoarchean and Paleoproterozoic tectono-thermal events recorded in the NCB basement, indicating that the source of the detritus was locally derived. By contrast, the hydrothermal ones are euhedral, sector zoning or internally structureless. They have relatively higher U and Th contents and Th/U ratios (U=139-2918 ppm, Th=35-1327 ppm, Th/U (average) =0.78 vs. U=15-1044 ppm, Th=8-341 ppm, Th/U (average) =0.57 for detrital zircons). Moreover, they are also enriched in REEs relative to detrital zircons and show a lower positive Ce anomaly (ΣREE = 659-2418 ppm vs. 231-611 ppm for detrital zircon; Ce/Ce*=2-13 vs. 33-174 for detrital zircons), similar to known hydrothermal zircons derived from many locations. These characteristics, combined with our field petrographic observations, indicate that the hydrothermal zircons possibly formed from a low temperature aqueous fluid. Twelve concordant or near-concordant analyses on hydrothermal zircons yield weighted mean Pb/U ages of 325-327 Ma, which provide unambiguous evidence that the northern NCB underwent late Paleozoic low temperature hydrothermal modification. This timing of this hydrothermal event is compatible with that of the late Paleozoic magmatic and metamorphic-deformational events occurred on the northern margin of the NCB, it appears likely that the hydrothermal activity resulted from southward subduction of the Paleo-Asian Oceanic plate underneath the NCB during late Paleozoic. [ABSTRACT FROM AUTHOR]

This paper reports the systematic study on petrology, geochemistry, LA ICPMS zircons U-Pb dating, and in situ Hf isotope geology of the four plutons in the central-southern Jiangxi Province, an important part of the South China Block. In the outcrops, rocks are gradually changed from wall rock (slate or schist) to pluton (gneissic granite); some residual blocks of sandy rock occur in the margin of pluton, and the foliations of residual blocks are parallel to those of both wall rock and gneissic granite. The thin-section observations show that the four plutons contain peraluminous minerals such as muscovite and sillimanite. The flattened and elongated feldspar and quartz grains are often visible in the gneissic granite, parallel to direction of lineation, suggesting that the granitic rock were subjected to a strong ductile shearing. Geochemically, the A/CNK values from 13 granitic samples are between 1.03 and 1.37 with an average of 1.16, indicating that the granites are of strongly peraluminous plutons. The REE compositions of the 13 samples are similar, showing higher ΣREE contents, with enrichment in LREEs, depletion in Eu and REE patterns with relative LREE-enrichment and negligible Eu anomalies. They show enrichment in Rb, Th, U and depletion in Ba, Sr, Nb, Ti, belonging to a low Ba-Sr type of granite. Thus, the four bodies should be derived from the same magmatic source. Zircons used as U-Pb dating mostly exhibit euhedral shape and high Th/U values from 0.52 to 1.54 with an average of 1.08, suggesting that most zircons are of magmatic genesis. The zircons from four plutons yielded rather similar Pb/U vs. Pb/U concordia ages: 436.1±5.7 Ma for the Tangwan granite, 440.6±4 Ma for the Jiekou gneissic granite, 435.9±6.2 Ma for the Dongbao gneissic granite, and 441.9±3.1 Ma for the Jinxi K-granite, respectively, corresponding to Silurian Llandovery. Several xenocrysts yielded U-Pb ages around 700 Ma, implying that a breakup event took place during Neoproterozoic in the South China Block. In situ Lu-Hf isotopic analysis shows that all ɛ( t) values of zircons are negative and have two-stage Hf model ages (TDM2) from 1.4 to 3.6 Ga, indicating that the Silurian granitic magma came from the recycle of Meso-Paleoproterozoic basement and even partly Archean rocks, and had not been effected by mantle magma. Researches on regional geology suggest that an intracontinental tectono-magmatic event took place during the early Paleozoic in the study areas, which is characterized by folding and thrusting, leading to crustal shortening and thickening, up to 20 km thickness. The high geothermal temperature from thickening crust and accumulation of producing high-heat radioactive elements gradually softened crustal rocks and caused a partial melting, forming peraluminous granitic magma. Under the post-orogenic extensional and de-pressure condition, these granitic magma rose and was emplaced in the upper crust, leading to development of S-type plutons [ABSTRACT FROM AUTHOR]

The atmospheric boundary layer (ABL) is an important physical characteristic of the Earth's atmosphere. Compared with the typical ABL, the ABL in arid regions has distinct features and is formed by particular mechanisms. In this paper, the depth of the diurnal and nocturnal ABLs and their related thermodynamic features of land surface processes, including net radiation, the ground-air temperature difference and sensible heat flux, under typical summer and winter conditions are discussed on the basis of comprehensive observations of the ABL and thermodynamic processes at the land surface carried out in the extreme arid zone of Dunhuang. The relationships of the ABL depth in the development and maintenance stages with these thermodynamic features are also investigated. The results show that the depth of the ABL is closely correlated with the thermodynamic features in both development and maintenance stages and more energy is consumed in the development stage. Further analysis indicates that wind velocity also affects ABL development, especially the development of a stable boundary layer in winter. Taken together, the analysis results indicate that extremely strong thermodynamic processes at the land surface are the main driving factor for the formation of a deep ABL in an arid region. [ABSTRACT FROM AUTHOR]

The N-S trending Xiaojiang fault zone and the NW-SE trending Qujiang-Shiping fault zone are adjacent active fault systems and seismogenic zones associated with strong and major earthquakes in Yunnan, China. To understand the interaction of the two fault systems, and its probable influence on earthquake occurrences, this paper conducts a synthetic study based on data of active tectonics, historical earthquakes, relocated small earthquakes, GPS station velocities and focal mechanism resolutions. The study makes several conclusions. (1) The active southward motion of the western side of the Xiaojiang fault zone (i.e. the side of the Sichuan-Yunnan block) has a persistent and intensive effect on the Qujiang-Shiping fault zone. The later fault zone has absorbed and transformed the southward motion of the western side of the former fault zone through dextral strike-slip/shearing as well as transverse shortening/thrusting. (2) Along the Xiaojiang fault zone, the present sinistral strike-slip/shearing rate decreases from 10 and 8 mm/a on the northern, central and central-southern segments to 4 mm/a on the southern segment. The decreased rate has been adjusted in the area along and surrounding the Qujiang-Shiping fault zone through reverse-dextral faulting and distributed shearing and shortening. (3) The tectonic-dynamic relation between the Xiaojiang fault zone and the Qujiang-Shiping fault zone is also manifested by a close correlation of earthquake occurrences on the two fault zones. From 1500 to 1850 a sequence of strong and major earthquakes occurred along the Xiaojiang fault zone and its northern neighbor, the Zemuhe fault zone, which was characterized by gradually accelerating strain release, gradually shortening intervals between M⩾7 events, and major releases occurring in the mid to later stages of the sequence. As a response to this sequence, after an 88-year delay, another sequence of 383 years (from 1588 to 1970) of strong and major earthquakes occurred on the Qujiang-Shiping fault zone, and had the same features in accelerating strain release and its temporal course. (4) Since there has been no M⩾7 event for 177 years on the Xiaojiang fault zone, the potential risk of a strong or major earthquake occurring on this fault zone in the future should be noticed and studied further. [ABSTRACT FROM AUTHOR]

In this paper, the spatial gravity distribution over Tibetan Plateau and the gravity rate of change at Lhasa for different Gaussian filter radii are computed using GRACE data. Results show that the estimate of the gravity rate of change is spatialradius-dependent of the Gaussian filter. The GRACE-estimated gravity rate of change agrees well with the surface measured one. In other words, the GRACE-estimated gravity rate of change has a limited value as that obtained by surface measurement when the spatial filter radius reaches zero. Then numerical simulations are made for different spatial radii of the Gaussian filter to investigate its behaviors when applied to surface signals. Results show that the estimate of a physical signal is filter-radius dependent. If the computing area is equal to or less than the mass area, especially for a uniformly distributed mass, the estimate gives an almost correct result, no matter what filter radius is used. The estimate has large error because of the signal leakage caused by harmonic truncation if the computing area is much bigger than the mass distribution (or inverse for a small mass anomaly). If a mass anomaly is too small, it is difficult to recover it from space observation unless the filter radius is extremely small. If the computing point (or area) is outside the mass distribution, the estimated result is almost zero, particularly for small filter radii. These properties of the Gaussian filter are helpful in applying GRACE data in different geophysical problems with different spatial position and geometrical size. We further discuss physical sources causing the scalar gravity change at Lhasa. Discussions indicate that the gravity rate of change at Lhasa is not caused by the present-day ice melting (PDIM) (or Little Ice Age, LIA) effect because no ice melting occurs in Lhasa city and nearby. The gravity rate of change is attributable mainly to tectonic deformation associated with the Indian Plate collision. Simultaneous surface displacement, surface denudation, and GIA effects are not negligible. [ABSTRACT FROM AUTHOR]

This paper retrieves the bidirectional polarization distribution functions (BPDFs) of the distinct urban cover in the Pearl River Delta (PRD) region employing the high spatial resolution of multi-angle polarized measurements made by the Directional Polarimetric Camera (DPC). The BPDF operational products of MICROPOL and POLDER measurements were used to validate the BPDF products of the DPC, with the results demonstrating that the BPDF product of the DPC measurements accurately expresses the surface polarized reflectance. The polarized reflectance of distinct surface types in the PRD region was studied using the DPC measurements. The results demonstrate that the polarized reflectances of different surface types differ and decrease as the normalized difference vegetation index increases. The polarized reflectance of a distinct surface type in the PRD region decreases with increasing scattering angle. The basic theory of investigating surface properties using multi-angle polarized measurements is proposed. [ABSTRACT FROM AUTHOR]

The Huangshan Mountain Geopark is an important geological landmark and tourist attraction. In this paper, we apply fission track dating to examine the uplift and exhumation processes that created the Huangshan Mountains and provide a timeline for their development. In addition to being an important scientific contribution, this information can be used on guided tours and to promote tourism. The results of eight apatite fission-track analyses suggest three age groups: 56, 45-30, and 15 Ma. These age groups are related to the uplifting-erosion processes involved in forming ancient multilevel denudation planes at 85-50, 45-30, and 24-5 Ma, respectively. The scenic area has experienced three stages of thermal evolution. The first stage occurred before 80 Ma and the third stage after 13 Ma. The three stages had varying cooling rates: 2.69, 0.62, and 4.23°C/Ma, respectively. Uplifting rates also varied: 0.08, 0.02, and 0.12 mm/a. The uplifting ranges were also variable: 1.14, 1.57, and 4.00 km, respectively. Significant uplifting differences between diverse areas are obvious and there were four magnitudes of cumulative uplifting range: 4060-3950, 3760-3490, 3190-3070, and 2650 m. The surface uplifting range varied from 450 to 2230 m. Denudation and uplifting amount averaged 2340 and 3400 m, respectively. The 1060 m difference between them is the average elevation at present. [ABSTRACT FROM AUTHOR]

This paper investigates the high-solution of Mo isotopes and uses trace-element analyses for fresh and representative black shales and siliceous shales collected from the transition between the Late Ordovician and the Early Silurian at the Wangjiawan section in Yichang and the Late Permian Dalong Formation in the Shangsi Section of Sichuan. The applicability of different geochemical parameters used as paleo-oxygenation indices are also compared. The preliminary results show that V/(V+Ni), U (auth U), V/Cr, Ce and U/Th have a scattered variation range, but most samples plot within the suboxic-anoxic fields. The suboxic-anoxic environment was dominant during the deposition and formation of the two anoxic facies. These redox indicators show little correspondence to the δMo values. The U/Mo ratio can be used as a potential proxy for the paleo-redox conditions due to the possibility that Mo is enriched relative to U at different redox gradients during early diagenesis. This evidence is more significant for the euxinicity condition and corresponds to positive δMo (>1.5‰) values with low U/Mo ratios. This evidence is likely related to the depositional conditions near the boundary between anoxic and euxinic environments, which are characterised by low bioturbation or water circulation. Other samples reveal a wide scatter of U/Mo ratios and δMo <1.5‰. These results are likely due to punctuated improvements in oxygenation with intense bioturbation or water circulation, which led to the redistribution of trace element. [ABSTRACT FROM AUTHOR]

Climate change adaptation and relevant policy-making need reliable projections of future climate. Methods based on multi-model ensemble are generally considered as the most efficient way to achieve the goal. However, their efficiency varies and inter-comparison is a challenging task, as they use a variety of target variables, geographic regions, time periods, or model pools. Here, we construct and use a consistent framework to evaluate the performance of five ensemble-processing methods, i.e., multi-model ensemble mean (MME), rank-based weighting (RANK), reliability ensemble averaging (REA), climate model weighting by independence and performance (ClimWIP), and Bayesian model averaging (BMA). We investigate the annual mean temperature (Tav) and total precipitation (Prcptot) changes (relative to 1995–2014) over China and its seven subregions at 1.5 and 2 °C warming levels (relative to pre-industrial). All ensemble-processing methods perform better than MME, and achieve generally consistent results in terms of median values. But they show different results in terms of inter-model spread, served as a measure of uncertainty, and signal-to-noise ratio (SNR). ClimWIP is the most optimal method with its good performance in simulating current climate and in providing credible future projections. The uncertainty, measured by the range of 10th-90th percentiles, is reduced by about 30% for Tav, and 15% for Prcptot in China, with a certain variation among subregions. Based on ClimWIP, and averaged over whole China under 1.5/2 °C global warming levels, Tav increases by about 1.1/1.8 °C (relative to 1995–2014), while Prcptot increases by about 5.4%/11.2%, respectively. Reliability of projections is found dependent on investigated regions and indices. The projection for Tav is credible across all regions, as its SNR is generally larger than 2, while the SNR is lower than 1 for Prcptot over most regions under 1.5 °C warming. The largest warming is found in northeastern China, with increase of 1.3 (0.6-1.7)/2.0 (1.4-2.6) °C(ensemble's median and range of the 10th–90th percentiles) under 1.5/2 °C warming, followed by northern and northwestern China. The smallest but the most robust warming is in southwestern China, with values exceeding 0.9 (0.6–1.1)/1.5 (1.1–1.7) °C. The most robust projection and largest increase is achieved in northwestern China for Prcptot, with increase of 9.1%(-1.6–24.7%)/17.9% (0.5–36.4%) under 1.5/2 °C warming. Followed by northern China, where the increase is 6.0%(-2.6–17.8%)/11.8% (2.4–25.1%), respectively. The precipitation projection is of large uncertainty in southwestern China, even with uncertain sign of variation. For the additional half-degree warming, Tav increases more than 0.5 °C throughout China. Almost all regions witness an increase of Prcptot, with the largest increase in northwestern China. [ABSTRACT FROM AUTHOR]

Prehistoric projectile weapons are crucial for understanding the hunting behavior, survival strategies, and subsistence patterns of prehistoric humans. Arrowheads were the primary prehistoric projectile weapon, and here we review the spatio-temporal distribution and changes in the morphology, quantity, and materials composition of arrowheads in the northern regions of China from the Middle and Upper Paleolithic periods to the Bronze Age, together with the factors that influenced these changes. The results reveal that primitive stone arrowheads appeared sporadically in the Middle Paleolithic period. Additionally, the "broad spectrum revolution" and microblade technology during the Upper Paleolithic promoted the regional-scale diffusion of broad and thick stone arrowheads in northern China. During the Neolithic period, relatively narrow and thin stone and bone arrowheads spread rapidly across the entire Yellow River Basin and most of northeastern China. The dominance of these two types of arrowheads alternated, during the period of 7000–5000 yr BP, the number of arrowheads peaked, possibly closely related to changes in the role of hunting (fishing and hunting) and gathering in the subsistence economy, human population size, and the emergence and development of a grinding technology. During the Bronze Age, a significant number of bronze arrowheads appeared, and the total number of arrowheads increased again, and their distribution expanded to northwestern China. The emergence of a bronze smelting technology and inter-group conflicts may have been the primary factors influencing this trend. Our results demonstrate that arrowheads were always an essential component of prehistoric tool kits. Due to technological developments in subsistence strategies, the morphology, function, and popularity of arrowheads underwent substantial changes during different periods. Therefore, a comprehensive study of prehistoric arrowheads can help better understand the subsistence patterns and processes of economic and societal development of prehistoric humans. [ABSTRACT FROM AUTHOR]

The ages of hydrothermal Hg deposits are difficult to constrain because of the lack of suitable minerals for dating. The South China low-temperature metallogenic domain hosts numerous Hg deposits, including the Jianyan Hg deposit that is composed mainly of cinnabar and calcite. There are two stages of calcite in the deposit: syn-ore calcite (Cal-I) and post-ore/barren calcite (Cal-II). Cal-I is mainly euhedral-subhedral and fine-grained, has homogeneous grey luminescence, and is associated with cinnabar. Subhedral-anhedral Cal-II crosscuts Cal-I and is relatively coarse-grained. The syn-ore Cal-I has high U contents (0.1–1.3 ppm) and U/Pb ratios (up to 4.2), and is thus suitable for U-Pb dating. Using a laser ablation-inductively coupled plasma-mass spectrometer equipped with ion counters, we obtained a U-Pb age of 426.3±5.7 Ma (MSWD=1.5) for Cal-I. This age is interpreted to represent the timing of Hg mineralisation at Jianyan and is similar to ages of 440–400 Ma reported for many carbonate-hosted Pb-Zn and Ba-F deposits in South China. Based on the present results in combination with existing geochemical and geochronological data, we infer that these deposits belong to a Paleozoic Hg-Pb-Zn-Ba-F mineralisation system that was controlled by Caledonian tectonism. [ABSTRACT FROM AUTHOR]

The contemporary carbon balance over the Tibetan Plateau is highly uncertain with a ten-fold difference between various estimates. In a warming world, the potential exists for a large carbon release from its permafrost which could compromise China's 2060 carbon-neutral goal. Here, we used a satellite- and inventory-based approach, ecosystem models, and atmospheric inversions to estimate that the carbon sink was 33.12–37.84 TgC yr−1 during 2000–2015. The carbon sink induced by climate change and increasing CO2 levels largely overcompensated for a livestock grazing-induced carbon source of 0.38 TgC yr−1. By 2060, the carbon sink is projected to increase by 38.3–74.5% under moderate to high emissions scenarios, with the enhanced vegetation carbon uptake outweighing the warming-induced permafrost carbon release. The restoration of degraded grassland could sequestrate an additional 9.06 TgC yr−1, leading to a total carbon sink of 57.78–70.52 TgC yr−1. We conclude that the Tibetan Plateau's ecosystems absorbed two-and-a-half times the amount of its cumulative fossil CO2 emissions during 2000–2015 and that their carbon sinks will almost double in strength in the future, helping to achieve China's pledge to become carbon neutral by 2060. [ABSTRACT FROM AUTHOR]

In this study, high-resolution Moho depth and average crustal Vp/Vs ratio distributions in northeast China were obtained through joint inversion of receiver functions and gravity data. The new joint inversion method comprehensively considers the complementary imaging strengths of the receiver functions in the vertical direction and the gravity data in the lateral direction. To a certain extent, it can reduce the adverse effects of the receiver function data caused by the sedimentary layers of the basin, the inclination of the Moho, and the structure heterogeneity below the station. In preprocessing the receiver function data, a regularized virtual station network was constructed using the teleseismic receiver function waveform reconstruction method to improve the overall spatial resolution. To filter the gravity data, the velocity structure-guided gravity filtering method and gravity upward continuation were used for the shallower region above the Moho and the deeper region below the lithosphere, respectively. The newly obtained model shows that the Moho depths of the Hailar Basin, Erlian Basin, Sanjiang Basin, and Bohai Bay Basin are slightly shallower than those of the surrounding areas, while the Moho depths of the Greater Xing'an Range, Lesser Xing'an Range, and Zhangguangcai Range are slightly deeper. Compared with previous results, the refined Moho depth distribution obtained in this study has a better correspondence with topographic relief and basin boundaries, and the contrast is more evident across the north-south gravity gradient lineament (NSGL). In the eastern part of the Songliao Basin, the Moho is relatively shallow, and there is a high Vp/Vs ratio, which may have been caused by the intrusion of hot mantle materials into the crust induced by lateral extension of the Songliao Basin. The high Vp/Vs ratio of the crust below the Changbaishan volcanic area implies the existence of partial melting in the crust caused by upwelling hot mantle materials. [ABSTRACT FROM AUTHOR]

Mid-high maturity shale oil is the most realistic field for the scale breakthrough of terrestrial shale oil production in China. Generally, three deficiencies hinder shale oil development in China: heavy oil density, small sweet spot areas, and poor distribution continuity. Thus, identifying the "sweet spots" in shale oil reservoirs is critical for the efficient exploration and development of terrestrial shale oil. This study targets the siltstone type (Class-II shale oil) and pure shale type (Class-III shale oil) of the Chang 7 Member in the Ordos Basin, and identifies three stratigraphic units, namely the hydrocarbon accumulation unit, hydrocarbon generation unit, and hydrocarbon retention unit, which together constitute the in-source "shale oil system". The hydrocarbon accumulation unit is mainly siltstone, where the hydrocarbons are migrated from shales. It has favorable pore-throat network connectivity with a pore connectivity ratio of 32–57%, being the siltstone-type sweet spots. The hydrocarbon generation unit is mainly composed of high-TOC mudstone/shale and is the main contributor to in-source hydrocarbon generation and expulsion. This unit has high three-dimensional connectivity (28–30%), as shown by the pore-throat network model, associated with vertical paths for hydrocarbon expulsion. The hydrocarbon retention unit is mainly composed of low-TOC mudstone/shale retaining self-generated and migrated hydrocarbons. The pore connectivity rate is 17–42%, and the pore-throat network connectivity direction is uneven. Light and low-carbon-number hydrocarbons are preferentially trapped or even sealed in small pores of the retention unit, forming the typical mudstone/shale-type sweet spots. In the process called shale oil intra-source migration, the oil migrates in source rocks causing component fractionation, which allows more shale oil to enrich in the hydrocarbon accumulation and retention units to form sweet spots, compared with the hydrocarbon generation unit. The migration paths include the one from mudstone/shale to siltstone interlayers and that from the high-TOC mudstone/shale intervals to the low-TOC intervals. The in-source accumulation of shale oil shows the differentiated enrichment model featuring "high-TOC mudstone/shale generating hydrocarbons, low-TOC mudstone/shale retaining hydrocarbons, siltstone accumulating hydrocarbons and multiple intra-source migration paths". In the Ordos Basin, the organic-lean (TOC 1–3%) mudstone/shale intervals appear to be the sweet spots of shale oil, where there are abundant medium-short-chain hydrocarbons retained with high flowability. After fracturing stimulation, their production conditions may be even superior to those of siltstones. This proposed idea changes the previous strategy to look for sweet spots in high-TOC intervals derived from the shale gas industry. [ABSTRACT FROM AUTHOR]