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The past ice sheet dynamics and the timing of retreat events in the paleo-record in the Ross Sea is an issue still few understood. In order to contribute to this topic, we provide a multiproxy data from marine sediment archives (cores and box cores) collected in three sites in the Central Basin (Western Ross Sea, Antarctica). Each site recorded different environments, affected by different oceanographic conditions and sedimentary regime. This makes the three investigated sediment cores and box cores unique and useful for comparison with other studied cores collected in the same basin. The data set includes physical (paleomagnetism, grain size and petrography), chemical, micropaleontological (diatom, foraminifera and silicoflagellate assemblages) analyses and cryptotephra characterization increasing the information already reported in literature. The importance of this dataset is related to a multi-disciplinary approach in a site, the Central Basin, few investigated which represents a key area to connect the Southern Ocean and the Ross Sea.

This observational study is concerned with the seasonal variability of near-inertial internal waves (NIWs) in the central part of the Black Sea. Rotary spectral analysis of the nearly year-long time series of the sea current velocity measurements at 100 m and 1700 m revealed the prevailing anticyclonic component of the motions near the local inertial frequency f. Both the rotary spectra and the visual exploration of the time series showed that the peaks of NIWs were blue-shifted to higher frequencies. The monthly average blue-shift was stronger up to 1.038f in the summer. It was found that the minimum intensification of the NIWs occurred in summertime and the maximum intensification was characteristic of the autumn-winter period when the NIW packets included up to 16 waves with pronounced clockwise rotation of the velocity vectors. [ABSTRACT FROM AUTHOR]

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This observational study is concerned with the seasonal variability of near-inertial internal waves (NIWs) in the central part of the Black Sea. Rotary spectral analysis of the nearly year-long time series of the sea current velocity measurements at 100 m and 1700 m revealed the prevailing anticyclonic component of the motions near the local inertial frequency f. Both the rotary spectra and the visual exploration of the time series showed that the peaks of NIWs were blue-shifted to higher frequencies. The monthly average blue-shift was stronger up to 1.038f in the summer. It was found that the minimum intensification of the NIWs occurred in summertime and the maximum intensification was characteristic of the autumn-winter period when the NIW packets included up to 16 waves with pronounced clockwise rotation of the velocity vectors.

A synthesis has been undertaken based on regionally compiled data from the post early Eocene foreland basin succession of Svalbard. The aim has been to generate an updated depositional model and link this to controlling factors. The more than kilometer thick progradational succession includes the offshore shales of the Gilsonryggen Member of the Frysjaodden Formation, the shallow marine sandstones of the Battfjellet Formation and the predominantly heterolithic Aspelintoppen Formation, together recording the progressive eastwards infill of the foredeep flanking the West Spitsbergen fold‐and‐thrust belt. Here we present a summary of the paleo‐environmental depositional systems across the basin, their facies and regional distribution and link these together in an updated depositional model. The basin‐margin system prograded with an ascending shelf‐edge trajectory in the order of 1°. The basin fill was bipartite, with offset stacked shelf and shelf‐edge deltas, slope clinothems and basin floor fans in the western and deepest part and a simpler architecture of stacked shelf‐deltas in the shallower eastern part. We suggest a foredeep setting governed by flexural loading, likely influenced by buckling, and potentially developing into a wedge top basin in the mature stage of basin filling. High‐subsidence rates probably counteracted eustatic falls with the result that relative sea‐level falls were uncommon. Distance to the source terrain was small and sedimentation rates was temporarily high. Time‐equivalent deposits can be found outbound of Stappen High in the Vestbakken Volcanic Province and the Sørvestsnaget Basin 300 km further south on the Barents Shelf margin. We cannot see any direct evidence of coupling between these more southerly systems and the studied one; southerly diversion of the sediment‐routing, if any, may have taken place beyond the limit of the preserved deposits. [ABSTRACT FROM AUTHOR]

Myanmar, one of the most active tectonic regions in the world, endures the risk of destructive earthquakes. Based on seismic data recorded at the recently deployed dense array of the China‐Myanmar Geophysical Survey in the Myanmar Orogen (CMGSMO), we detect 854 and locate 599 shallow earthquakes with high precision and determine the focal mechanisms of 40 earthquakes. We identify two NW‐SE trending fault zones accommodating dextral strike‐slip earthquakes beneath the Central Basin, indicating potential seismic risk in the region. We also recognize a nearly N‐S trending seismic zone in the overlying Indo‐Burma Ranges (IBR) crust near the Kabaw Fault (KBF). The earthquakes within this seismic zone mostly show thrusting focal mechanisms. Our results suggest that strike‐slip deformation dominates to the east of the KBF, while shortening is mainly confined to the west of the KBF in Central Myanmar. Plain Language Summary: Myanmar in Southeast Asia suffers from disasters resulting from destructive earthquakes. However, the present knowledge on their causative faults is limited due to the deployment of few seismic observation stations in Myanmar. We deployed a seismic observation network containing 71 stations for 1.5 years and tried to identify unknown causative faults and their characteristics by studying the small earthquakes there. Our results suggest that larger areas than previously expected in Myanmar may encounter significant seismic hazards. More attention to mitigating hazards should be paid to the Central Basin and western mountain areas, where densely populated cities are located. Key Points: We detect 854 shallow earthquakes and analyze the focal mechanisms of 40 events based on the data set from a new seismic array in MyanmarWe identify two fault zones in the Central Basin that may accommodate surplus strike‐slip deformations not taken up by the Sagaing FaultWe observe a lower‐crustal seismic zone west of the Kabaw Fault, which is controlled by eastward subduction of the Indian Plate [ABSTRACT FROM AUTHOR]

The continental margin is a key area for studying the sedimentary processes related to the advance and retreat of the Ross Ice Shelf (Antarctica); nevertheless, much remains to be investigated. The aim of this study is to increase the knowledge of the last glacial/deglacial dynamics in the Central Basin slope–basin system using a multidisciplinary approach, including integrated sedimentological, micropaleontological and tephrochronological information. The analyses carried out on three box cores highlighted sedimentary sequences characterised by tree stratigraphic units. Collected sediments represent a time interval from 24 ka Before Present (BP) to the present time. Grain size clustering and data on the sortable silt component, together with diatom, silicoflagellate and foraminifera assemblages indicate the influence of the ice shelf calving zone (Unit 1, 24–17 ka BP), progressive receding due to Circumpolar Deep Water inflow (Unit 2, 17–10.2 ka BP) and (Unit 3, 10.2 ka BP–present) the establishment of seasonal sea ice with a strengthening of bottom currents. The dominant and persistent process is a sedimentation controlled by contour currents, which tend to modulate intensity in time and space. A primary volcanic ash layer dated back at around 22 ka BP is correlated with the explosive activity of Mount Rittmann.

Medium- and high-K calc-alkaline magmatism of the Shurab (southeast Qom city) and Garmsar (northwest Garmsar city) areas occurred within the Lower Red Formation in the Central Basin behind the Urumieh-Dokthar Magmatic Arc. In terms of whole-rock geochemical analyses and in agreement with the petrographic features, all representative samples of the Shurab area are classified into three groups: group 1 with mainly intergranular texture comprises basalt/trachybasalt, while groups 2 and 3 with trachytic and porphyritic textures, respectively, have basaltic trachyandesite composition. The overall major constituents are plagioclase with composition in the range from An49Ab23 to An75Ab47, clinopyroxene with composition in the range Wo43-45En39-45Fs9-15, and olivine with composition in the range from Fo58Fa31 to Fo67Fa40. Minor minerals consist of opaque minerals and K-feldspar in the range Or41-65Ab33-50An0.69-8. The characteristic accessories are apatite and sphene. In the Garmsar area, rocks are seen as subvolcanic with mafic (basalt) and intermediate (trachybasalt/basaltic trachyandesite) compositions. The Garmsar area rocks represent intergranular, granular, ophitic, and subophitic textures. In these rocks, major mineral phases are plagioclase and clinopyroxene. The minor constituents are olivine, opaque minerals, amphibole, biotite, and quartz. Apatite is the most important accessory mineral. The rocks of both areas display REE patterns characterized by LREE-enriched and HREE-depleted segments typical of arc lavas. Primitive mantle-normalized trace element patterns for samples of both areas exhibit high ratios of strongly incompatible elements with similar bulk partition coefficients (e.g., Th/ Ta and Th/Ce), enrichment in large-ion lithophile elements (LILEs: Cs, Ba, Rb, Th) relative to the high field-strength elements (HFSEs: Ti, Hf, Zr, and REEs), and troughs for Nb, Ta, Ti, and Zr and peaks for Cs, Th, K, and Sr, all of which are indicators for subductionrelated magmatism. Subduction of the Neo-Tethys beneath the Eurasian margin led to upper mantle deformation and metasomatism. Once the Arabian plate collided with the Eurasian margin, subduction ended through a slab breakoff process, and thermal flux of asthenospheric origin uprising through the slab tear induced the thermal erosion of the mantle metasomatized during the previous subduction event and triggered its partial melting. Also, the late Eocene-early Oligocene collision of Eurasian with Arabian plates led to the subsidence and formation of faults and extensions in the Central Basin (i.e. the Shurab and Garmsar areas) such that eruption of medium- and high-K metasomatic magmatism along these faults and extensions caused postcollision volcanism in the Central Basin. [ABSTRACT FROM AUTHOR]

This study is based on the geological and geophysical data obtained in the Bay of Bengal and adjacent part of the Mid-Indian Ocean Basin by different Russian scientific and industrial institutions in the 1980s and 1990s. The results of the more recent foreign investigations are also involved. The analysis of the collected data provided a new insight into the geological structure and evolution of the region indicating that a large dry-land area-the Bengal elevation-existed in the Cretaceous at the location of the present-day Bay of Bengal. During the Cretaceous, the geological evolution of this area was controlled by epicontinental sedimentation and active volcanism. In the Late Cretaceous, progressive submersion with the inception of the Central Basin took place in the region. The subsidence of the basement was accompanied by active differentiated tectonic movements in the southern part of the Bay of Bengal. As a result, the basement experienced fragmentation into blocks with the formation of horst and graben structures. The horst relics eventually submerged to the current depths in the Late Miocene-Pliocene. The maximal amplitude of basement submersion within the bay is more than 11 km. [ABSTRACT FROM AUTHOR]

Abstract: In Central Iran two adjacent anticlines contain hydrocarbons within the Late Oligocene–Early Miocene Qom Formation. The anticlines formed at approximately similar times (Late Miocene–Pliocene), have similar overall geometries, but the Alborz Anticline is an oil field, while the Sarajeh Anticline is a gas field, and both are underfilled structures. Basin modeling and structural restorations identified why the two different accumulations developed. The Sarajeh and Alborz anticlines are modified detachment anticlines. Asymmetric development of growth strata on the SW margin of the folds was caused by salt withdrawal and normal fault activity on the basin margin, which modified the detachment fold style and tilted the basal detachment to the SW. The detachment dies out to the NE as the basal (Lower Red Formation) evaporites pinch out in the same direction, yet the Alborz Anticline is north vergent, while the Sarajeh Anticline is south vergent. The mini salt-withdrawal basin is best developed on the southern limb of the Sarajeh Anticline and is responsible for the SW vergence. This difference in vergence permitted the Alborz Anticline to attain 4-way dip closure earlier in its structural history than the Sarajeh Anticline, and consequently the trap was at least partially developed as a four-way closure during oil generation and expulsion. For the Sarajeh Anticline oil migrated across the fold when it was still unclosed, continued subsidence of the SW fold limb resulted in gas generation and expulsion during the time when the fold attained closure. [Copyright &y& Elsevier]

Abstract: During continent–continent convergence of the Arabian and Eurasian plates, and after the late Eocene inversion of a back-arc rift, the Iranian Plateau underwent broad subsidence resulting in the formation of the Central Basin (Morley et al., 2009). New 2D seismic data acquired by National Iranian Oil Company (NIOC) in the NW–SW-trending arm of the Central Basin suggest that during the main stage of shortening (middle–late? Miocene to Pliocene), strain concentrations resulted in the development of the thin-skinned Kuh-e-Gachab, Kuh-e-Gugerd, Garmsar and Sorkh-e-Kuh structures. These structures are built of Oligocene–Miocene/Pliocene(?) rocks belonging to the Lower Red, Qom and Upper Red formations. Seismic data suggest that one of these structures comprises the south-verging Kuh-e-Gachab anticline, which is bounded by the N-dipping Kuh-e-Gachab thrust and cored by a complex array of thrust sheets forming a triangle zone. During the deformation process, two salt evaporate levels played a significant role as detachment horizons. The main detachment horizon was rooted within the Lower Red Formation, whereas the second detachment horizon was located along evaporites belonging to the Upper Red Formation. Variations in the thin-skinned style of deformation between the larger triangle zone in the western part of the Kuh-e-Gachab structure contrasts with less shortening in the smaller triangle zone to the east. This suggests that the change resulted from the increase of thickness of the mobile detachment horizon to the east. Contraction deformations are still active south of the Alborz Mountains, which is confirmed by GPS data and present-day seismicity. [Copyright &y& Elsevier]

Within a successional context, the vegetation associated with the cedar glade ecosystem in middle Tennessee develops from bare limestone bedrock to subclimax redcedar, preclimax oak-hickory, and climax mixed hardwood forests. Studies on the composition and structure of forests associated with cedar glade-forming limestones (Lebanon, Ridley) are rare. We sampled the canopy and understory of six forest stands in middle Tennessee on these limestones. Observed number of canopy species was 14-24 across stands; estimated richness was greater by 1-3 species (bootstrap) or 3-6 species (first-order jackknife) than observed richness. With the exception of Ailanthus altissima in one stand, all other canopy species were native. Juniperus virginiana, Fraxinus americana, Carya ovata, and Quercus muehlenbergii were primary canopy components in 4 or 6 stands, and C. glabra, Q. shumardii, Ulmus alata, F. quadrangulata, Q. alba, and Q. velutina in 2-3 stands. When we included stands from a previously published study (most on the non-glade Carters Limestone) with our data, a principal components analysis identified three groups with the axes approximating a moisture-bedrock gradient and a time-successional gradient. An examination of regeneration in our stands predicts that (1) mesophytes and/or fire-sensitive species (Acer saccharum, Fraxinus spp., Celtis spp.) will increase and (2) xerophytes and/ar fire-adapted species (Quercus spp., Carya spp.) will decrease. Altogether, our results strongly suggest that the oak-hickory stage shown in successional outlines of vegetation development associated with the cedar glade ecosystem may not occur in its current state in the future. [ABSTRACT FROM AUTHOR]

In the Central Iran Basin, the mixed carbonate–siliciclastic deposits of the C member of the Qom Formation were deposited on a carbonate platform which is dominated by rhodalgal associations occurring in tropical–subtropical environment. The biogenic rhodalgal association is dominated by bryozoa, coralline red algae, bivalves and echinoids together with smaller amounts of photo-dependent biota including large benthic foraminifera and corals. The abundance of heterozoan association and the bloom of suspension-feeding organisms are the result of an increase in nutrient availability which has profound controlling effect on the biotic system. The low occurrence of symbiont-bearing benthic foraminifera and coral, typical of stable, oligotrophic condition, represents their low tolerance to unstable, nutrient-rich environment. In the investigated Oligocene–Miocene shallow marine carbonate succession, 10 different microfacies were distinguished through depositional texture and biotic components. The rock sequences investigated are referred to an open shelf carbonate platform in which the depositional environments range from outer shelf to inner shelf conditions. [ABSTRACT FROM PUBLISHER]

Central Basin of Cuba is one of the most important places by its geological and economical interest. Several geophysical investigations have been carried out during the exploration stage placing emphasis on the gravimetrical surveys. Considering the results obtained with gravimetry in other investigated areas, in this study a qualitative interpretation was made of the gravimetric data 1:100 000. Initially, different transformations from the gravimetric field were made (Ascending Analytical Continuation and horizontal calculations of gradients), then they were plotted on isolines and shaded relief map for later qualitative interpretation. New structural regularities of the Central Basin were established which demonstrates the noticeable tectonic control of region. Most of the known faults systems are related with alienations in the gravimetric field, likewise alienated zone exist mainly in the northeast, southeast and northeast-southeast directions, which are associated to these systems and cannot constitute faults zones that were not reported in previous investigations. The presence of great positive anomalous zones under the quaternary sequences indicates that volcanogeno-sedimentary or volcanogeno-deposited during the cretacic volcanic activity exist at depth. A zone of high gradients with northeastern-southwestern direction is defined, which indicates the limit between the flooded and overlying sequences of the passive paleomargin and the emigraben of the Central Basin. In the far north occidental and central regions, the rocks of low densities reach their greatest depths, whereas the high density ones are found in the occidental part of the region. All the elements indicated, will allow one better planning of future geologic investigations in the region. [ABSTRACT FROM AUTHOR]

Round gobies, invasive fish that entered Lake Erie in 1994, are altering energy, contaminant, and nutrient pathways. Our objective was to quantify how they alter energy pathways in the central basin of Lake Erie by describing their diet and identifying the degree to which predatory fish feed upon round gobies. We used bioenergetic models parameterized with data collected in the central basin between 1995 and 2002 to estimate the type and amount of prey eaten, the biomass accumulation rate for the round goby population, and a partitioning of the food energy into ‘new’ energy derived from dreissenids as opposed to existing energy derived from zooplankton and non-dreissenid benthic prey. Mean (± SE) prey consumption peaked at 5.98 ± 2.17 × 104 tonnes wet mass in 1999 coincident with the maid- mum population size of 4.2 ± 1.5 billion round gobies. Zooplankton (40.2% by biomass) and dreissenid mussels (38.3%) dominated the prey consumed. Almost 90% of the zooplankton biomass was consumed by age-O round gobies, while over 80% of the dreissenids were eaten by older ages. Standing stock biomass of round gobies ranged between 203 and 4,803 tonnes y-¹ (interannual range), with an additional 475 to 8,943 tonnes of biomass accumulating through growth each year. Piscivorous fish showed an increasing reliance on round gobies as prey, with round gobies being the dominant prey fish in the diets of benthic-oriented predators. Hence, by being one of the few benthivores that exploit dreissenid mussels as prey, our analyses reveal that round gobies transfer new energy up the central Lake Erie food web. [ABSTRACT FROM AUTHOR]

The continental margin is a key area for studying the sedimentary processes related to the advance and retreat of the Ross Ice Shelf (Antarctica); nevertheless, much remains to be investigated. The aim of this study is to increase the knowledge of the last glacial/deglacial dynamics in the Central Basin slope–basin system using a multidisciplinary approach, including integrated sedimentological, micropaleontological and tephrochronological information. The analyses carried out on three box cores highlighted sedimentary sequences characterised by tree stratigraphic units. Collected sediments represent a time interval from 24 ka Before Present (BP) to the present time. Grain size clustering and data on the sortable silt component, together with diatom, silicoflagellate and foraminifera assemblages indicate the influence of the ice shelf calving zone (Unit 1, 24–17 ka BP), progressive receding due to Circumpolar Deep Water inflow (Unit 2, 17–10.2 ka BP) and (Unit 3, 10.2 ka BP–present) the establishment of seasonal sea ice with a strengthening of bottom currents. The dominant and persistent process is a sedimentation controlled by contour currents, which tend to modulate intensity in time and space. A primary volcanic ash layer dated back at around 22 ka BP is correlated with the explosive activity of Mount Rittmann. [ABSTRACT FROM AUTHOR]