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Whole-rock geochemical and U-Pb-Hf isotopic data were used to investigate the age, petrogenesis, and tectonic setting of a suite of gabbro-diorite-monzonite-syenite rock exposed in Qinsai area, Hainan Island. Zircon U-Pb dating shows that the gabbro and monzonite, respectively, crystallized at 179.5 [+ or -] 2.7 and 179.0 [+ or -] 2.3 Ma. The suite consists of shoshonitic alkaline intrusive rocks with [SiO.sub.2] content ranging from 41.7 to 63.4 wt%, with high U, K, and Pb and low Nb, Ta, and Ti. The suite is enriched in light rare earth elements relative to heavy rare earth elements. The gabbro has no obvious Eu anomaly but a positive Eu anomaly is evident in intermediate rocks. Zircon [[epsilon].sub.Hf](t) values are positive and have a wide variation (gabbro [[epsilon].sub.Hf](t) = +5.2 [+ or -] 8.2, monzonite [[epsilon].sub.Hf](t) = +4.7 [+ or -] 7.1). Gabbro and syenite are both likely derived from an enriched lithospheric mantle that was metasomatized by subduction fluids. Syenite evolved from the differentiation of gabbro, monzonite, and diorite. Collectively these intrusive rocks formed in an extensional regime within an arc formed by subduction of the ancient Pacific plate beneath the Asian margin, which was accompanied by extensional thinning of the lithosphere. Key words: Hainan, Middle Jurassic, intrusive rocks, U-Pb age, geochemistry, petrogenesis, Introduction The South China plate is located to the south of the Chinese mainland. Since the Late Paleozoic, the southeastern margin of the South China plate has been affected by [...]

The Lower Cretaceous of the eastern depression in the North Yellow Sea Basin is a set of residual strata that can be divided into [K.sub.1]sq1 and [K.sub.1]sq2 sequences. There are four lithology-lithofacies architectures summarized in the third-order sequences of wells W5, W3, W1, W9, W16, W7, W8, and W10, and they are the coarse-fine-coarse, asymmetric coarse-fine, asymmetric fine-coarse, and interbedded coarse and fine. F1, F4, F6, and F7, which are strike-slip faults, were dominant during the Early Cretaceous, and controlled the eastern depression to undergo right-lateral movement from transtension to transpression. The tectonic movement controlled different stratigraphic structure in different areas, and the fan bodies deposited along the basin margin and progradated into the basin center. The sequence models under extensional and strike-slip setting were established respectively. The transtension-transpression movement controlled the development of the sandstones in the Lower Cretaceous and improved the quality of the reservoir rocks. Key words: North Yellow Sea Basin, eastern depression, Lower Cretaceous, stratigraphic characteristics, transtension-transpression, tectonic control. Le Cretace inferieur de la depression orientale dans le bassin du nord de la mer Jaune est constitue d'un ensemble de strates residuelles pouvant etre subdivisees en les sequences [K.sub.1]sq1 et [K.sub.1]sq2. Quatre architectures lithologiques/de lithofacies sont resumees dans les sequences de troisieme ordre des sondages W5, W3, W1, W9, W16, W7, W8 et W10, a savoir : grenus--fins--grenus, grenus--fins asymetriques, fins--grenus asymetriques, et grenus et fins interstratifies. F1, F4, F6 et F7, des failles de decrochement, ont joue un role dominant durant le Cretace precoce, controlant un deplacement dextre de la depression orientale pour mener au passage d'un regime de transtension a un regime de transpression. Les deplacements tectoniques controlaient differentes structures stratigraphiques dans differents secteurs, et des corps de depots de cones se sont accumules le long de la marge du bassin, montrant une progradation vers le centre de celui-ci. Des modeles de sequences pour des scenarios de milieux d'extension et de decrochement ont ete etablis. Les deplacements en transtension--transpression ont controle la formation des gres dans le Cretace inferieur et rehausse la qualite des roches-reservoirs. [Traduit par la Redaction] Mots-cles: bassin du nord la mer Jaune, depression orientale, Cretace inferieur, caracteristiques stratigraphiques, transtension--transpression, controle tectonique., Introduction The North Yellow Sea Basin is a Meso-Cenozoic continental sedimentary basin located between the Tan-Lu fault and the Sulu-Imjingang orogenic belt (hereinafter referred to as the belt) (Fig. 1a). [...]

Controversies exist regarding the mechanismofformationofbasins locatedonthe continental marginof South China as well as when they formed. It was ascertained based on clastic petrology, geochemical analysis, and zircon U--Pb dating that the sedimentary provenances in the eastern Guangdong Basin are mainly felsic igneous rocks from the late Early Jurassic to the Middle Jurassic. The late Early Jurassic Qiaoyuan Formation mainly shows major age peaks atapproximately 238 Ma, 259 Ma, and 1858 Ma, and the Middle Jurassic Tangxia Formation shows major age peaks at approximately 169 Ma and 172 Ma. From the late Early Jurassic to the Middle Jurassic in the eastern Guangdong Basin, the source region changes from southwestern South China and southern South China to the eastern Nanling Range. It was determined by comparing the detrital zircon ages of the Qiaoyuan Formation and the Tangxia Formation with thoseofthe late Paleozoictoearly Mesozoic basins, and analyzing both the geochemical data and sedimentation, that the eastern Guangdong Basin changed from the basin-arc foreland basin of the late Early Jurassic to the back-arc extension basin of the Middle Jurassic. The changes in early Mesozoic detrital zircon age peaks indicate that the tectonic regime of the eastern Guangdong Basin ended the transformation from the Tethyan tectonic domain to the paleo-Pacific tectonic domain in the early Middle Jurassic (approximately 172 Ma). Key words: eastern Guangdong Basin, late Early Jurassic to Middle Jurassic, provenances, tectonic regime transformation, zircon U--Pb dating. Des controverses persistent quant au mecanisme de formation de bassins situes sur la marge continentale de la Chine meridionale, ainsi qu'au moment de leur formation. Il a ete etabli, sur la base de la petrologie, l'analyse geochimique et la datation U--Pb sur zircons de depots clastiques que les sources de sediments dans le bassin de Guangdong oriental sont principalement des roches ignees felsiques d'age jurassique precoce tardif a jurassique moyen. La Formation de Qiaoyuan du Jurassique precoce tardif produit principalement de grands pics d'ages vers 238 Ma, 259 Ma et 1858 Ma, et la Formation de Tangxia du Jurassique moyen donne de grands pics d'ages vers 169 Ma et 172 Ma. Du Jurassique precoce tardif au Jurassique moyen dans le bassin de Guangdong oriental, la region source passe du sud-ouest et du sud de la Chine meridionale a la chaine de Nanling orientale. Il est determine, en comparant les ages de zircons detritiques des Formations de Qiaoyuan et de Tangxia a ceux des bassins d'age paleozoique tardif a mesozoique precoce et en analysant les donnees geochimiques et la sedimentation, que le bassin de Guangdong oriental est passe d'un bassin d'avant-pays d'un systeme arc-bassin au Jurassique precoce tardif a un bassin d'extension d'arriere-arc au Jurassique moyen. L'evolution des pics d'ages de zircons detritiques du Mesozoique precoce indique queleregime tectonique danslebassindeGuangdong orientalacloslatransformationdudomaine tectonique tethysien en un domaine tectonique paleopacifique au Jurassique moyen precoce (vers 172 Ma). [Traduit par la Redaction] Mots-cles : bassin de Guangdong oriental, Jurassique precoce tardif--Jurassique moyen, provenances, transformation du regime tectonique, datation U--Pb sur zircons., Introduction The main geotectonic outline of South China and even eastern China is controlled by the Indosinian and Yanshan movements (Wang and Zhou 2006; He et al. 2007; Z.H. Li [...]

Based on research of the petrology, geochemistry, and zircon U-Pb dating of detrital rocks in the Late Triassic Wenbinshan Formationin southwestern Fujian, and comparing the detrital zircon ages of Wenbinshan Formation with those of Late Paleozoic--Early Mesozoic main basins in South China, the sedimentary provenance of the Late Triassic in southwestern Fujian and its implications for changes in basin properties are discussed. The research results demonstrate that there is a major age peak at 222 Ma, two subordinate age peaks at 275 Ma and 1851 Ma, and two minor age peaks at 413 Ma and 2447 Ma in the detrital zircon age spectra of the upper samples (YGP-6) of the Wenbinshan Formation, whereas there are two major age peaks at 229 Ma and 1817 Ma and other minor age peaks 265 Ma 309 Ma, 415 Ma, 1968 Ma, and 2435 Ma in the detrital zircon age spectra of the lower samples (YGP-26) of the Wenbinshan Formation. The upper samples contain fewer old detrital zircons than the lower samples, but the upper and lower samples of Wenbinshan Formation are similar in major age composition, which indicates the main provenances of the upper and lower sediments are very similar. The source rocks are mainly sedimentary rocks and their provenances are derived from a source area of recycled orogenic belt and volcanic arc orogenic belt (acidic island arc). The detrital zircon composition of the Wenbinshan Formation is mainly composed of Paleoproterozoic zircon and Late Paleozoic-Early Mesozoic zircon. In the Paleoproterozoic, sedimentary provenances were mainly derived from the Wuyi Massif and partly from northwestern Fujian-southwestern Zhejiang. As for the period of Late Paleozoic-Early Mesozoic, the provenances of the Wenbinshan Formation were derived from magmatic active belts of the Early Indosinian Epoch of northern South China, eastern South China, and the Indosinian Period of northern South China and coastal areas of eastern South China. The similarities and differences between detrital zircon age peaks of the Wenbinshan Formation in southwestern Fujian and that of the main basins in South China during the period of Late Paleozoic-Early Mesozoic indicate that from eastern coastal areas of South China to the north and interior of South China, the age composition of basin sediments has changed from simple to relatively complex, and from young sediments to older sediments. There are similarities and differences in the detrital zircon compositions of the different basins, which can indicate differences in the nature of the basins. Key words: Southwestern Fujian, Late Triassic, zircon U-Pb dating, provenances, Indosinian movement. A la lumiere de travaux sur la petrologie, la geochimie et la datation U-Pb sur zircons de roches detritiques de la Formation de Wenbinshan du Trias tardif dans le sud-ouest de la province du Fujian, et de la comparaison des ages de zircons detritiques de cette formation a ceux de principaux bassins d'age paleozoique tardif a mesozoique precoce en Chine meridionale, la provenance sedimentaire des sediments du Trias tardif dans le sud-ouest du Fujian et ses consequences pour la comprehension des variations des proprietes des bassins sont abordees. Les resultats de ces travaux demontrent une pointe d'ages majeure a 222 Ma, deux pointes subordonnees a 275 Ma et 1851 Ma et deux pointes mineures a 413 Ma et 2447 Ma dans les spectres d'ages de zircons detritiques de la partie superieure (YGP-6) de la Formation de Wenbinshan, alors qu'il y a deux pointes d'ages majeures a 229 Ma et 1817 Ma et d'autres pointes mineures a 265 Ma, 309 Ma, 415 Ma, 1968 Ma et 2435 Ma dans les spectres d'ages de zircons detritiques de la partie inferieure (YGP-26) de cette formation. Les echantillons superieurs contiennent moins de vieux zircons que les echantillons inferieurs, mais les echantillons superieurs et inferieurs presentent des pointes d'ages majeures semblables, ce qui indique que les principales provenances des sediments superieurs et inferieurs sont tres semblables. Les roches sources consistent principalement en des roches sedimentaires derivees de ceintures orogeniques recyclees et de ceintures d'arc volcanique (arc oceanique acide). Les zircons detritiques de la Formation de Wenbinshan comprennent principalement des zircons paleoproterozoiques et des zircons paleozoiques tardifs a mesozoiques precoces. Durant le Paleoproterozoique, les sediments provenaient principalement du massif de Wuyi et en partie du nord-ouest du Fujian et du sud-ouest du Zhejiang. En ce qui concerne la periode du Paleozoique tardif au Mesozoique precoce, les sediments de la Formation de Wenbinshan proviennent de ceintures magmatiques actives du debut de l'epoque indosinienne du nord et de l'est de la Chine meridionale, ainsi que de la periode indosinienne du nord et de zones cotieres de l'est de la Chine meridionale. Les similitudes et differences entre les pointes d'ages de zircons detritiques de la Formation de Wenbinshan dans le sud-ouest de la province du Fujian et des principaux bassins d'ages paleozoiques tardifs a mesozoiques precoces en Chine meridionale indiquent que, des zones cotieres orientales jusqu'au nord et a l'interieur de la Chine meridionale, la composition des ages des sediments de bassin est passee de simple a relativement complexe, et de sediments jeunes a des sediments plus vieux. La composition des zircons detritiques des differents bassins presente des similitudes et des differences, ce qui indique des variations de la nature des bassins. [Traduit par la Redaction] Mots-cles : sud-ouest de la province du Fujian, Trias tardif, datation U-Pb sur zircon, provenance, mouvement indosinien., 1. Introduction The Indosinian and Yanshan movements were two tectonic movements that formed the main tectonic framework during the formation of South China and East China (Lin et al. 2013; [...]

The Jiamusi Block is a crucial geological unit joining multiple tectonic regimes, including the Late Palaeozoic Palaeo‐Asian Ocean and the superposition of the Early Mesozoic Palaeo‐Pacific tectonic domain. However, the duration of the Palaeo‐Pacific Plate subduction beneath the Jiamusi Block has long been controversial. In this paper, we focus on clastic rocks from the Nanshuangyashan and Yunshan formations on the east margin of the Jiamusi Block and use the modal analysis of sandstones and detrital zircon U–Pb dating to trace the subduction history of the Palaeo‐Pacific Plate. Our analysis results suggest that the two groups of samples are characterized by a high content of monocrystalline quartz and a low content of lithic and feldspar, indicating that the sedimentary provenances were stable continental blocks and magmatic arcs. The detrital zircon ages of the Nanshuangyashan Formation have a major peak at ca. 245 Ma and two secondary peaks at ca. 470 and 228 Ma, respectively. The Yunshan Formation has a major peak at ca. 494 Ma and a secondary peak at ca. 265 Ma. The provenances of the Nanshuangyashan Formation were attributed to the Jiamusi Block, Khanka Block, and a Late Triassic magmatic arc. Similarly, the provenances of the Yunshan Formation were attributed to the Jiamusi and Khanka blocks. Detrital zircon analysis results show that the eastern margin of the Jiamusi Block was in the same back‐arc basin settings in the Late Triassic and the Late Jurassic. Thus, we propose that the eastern margin of the Jiamusi Block had been affected by the Palaeo‐Pacific Plate subduction in the Late Triassic and had continued to the Late Jurassic. [ABSTRACT FROM AUTHOR]

In the Late Mesozoic, the Eastern North China Craton changed from being controlled by the Palaeo‐Asian tectonic domain to the marginal Pacific tectonic domain. The Eastern North China Craton transformed the E–W compression to NNE–SSW extensional tectonics under the influence of two tectonic domain transformations. However, the timing of the transformation of the tectonic domains remains controversial. The North Yellow Sea Basin is located in an important position in the Eastern North China Craton at the junction of the Pacific and Eurasian plates and is controlled by two tectonic domains. Therefore, the sediments in the basin are faithful records of the transformation of the two tectonic domains. Based on the latest and high‐precision detrital zircon U–Pb dating data, sandstone modal analysis, and elemental geochemical analysis in the North Yellow Sea Basin combined with regional tectonic, palaeontological, and palaeoclimatic evidence, this paper discusses the provenance from the Middle Jurassic to Early Cretaceous, which responds to the Late Mesozoic tectonic domain transformation in the Eastern North China Craton, and provides important evidence of provenance in the North Yellow Sea Basin to determine the time of tectonic domain transformation. These results suggest that the source rocks of sediments in the North Yellow Sea Basin have changed from ancient sediments (ancient craton/recycle orogenic belt) in the Middle Jurassic to Late Jurassic, to felsic igneous rocks in the Early Cretaceous. The peak of zircon U–Pb ages changed from 234, 1,842, and 2,429 Ma in the Late Jurassic to 217 and 1,871 Ma in the Early Cretaceous. The provenance changed from the Sulu Orogenic Belt and Precambrian basement of the Jiaodong Peninsula in the Late Jurassic, to the igneous rocks and Precambrian basement of the Liaodong Peninsula and Korean Peninsula in the Early Cretaceous. The provenance direction of the sediments changed from south‐west in the Late Jurassic to the north and south‐east in the Early Cretaceous. The tectonic setting of the basin changed from compression to extension. The changes in the peaks of zircon U–Pb age, characteristics of the source rocks, provenance direction, and basin tectonic setting in the Middle Jurassic to Early Cretaceous in the North Yellow Sea Basin are a response to the change from E–W compression to NNE–SSW extensional tectonics caused by the transformation of two tectonic domains. In the Early Cretaceous, the Eastern North China Craton completed the transformation of two tectonic domains that were influenced and controlled by the marginal Pacific tectonic domain. [ABSTRACT FROM AUTHOR]