Phylloid algae arc important rcef-builders in the late Carboniferous. This paper focuses on the paleoecology of phylloid algae in the Late Carboniferous on well-exposed reefs in Ziyun County, Guizhou Province. Phylloi...Phylloid algae arc important rcef-builders in the late Carboniferous. This paper focuses on the paleoecology of phylloid algae in the Late Carboniferous on well-exposed reefs in Ziyun County, Guizhou Province. Phylloid algae growing closely packed arc attached via holdfast or similar structure to substrate. They were growing in environments such as shallow water, photic zone and below the wave base with medium energy currents. They have a variety of morphological forms, such as single cup-shaped, cabbage-shaped and clustering cup-shaped. The thalli arc of certain tenacity and intensity. In the areas dominated by phylloid algae, other marine orgam＇sms arc relatively scarce. Obviously, phylloid algae arc stronger competitors for living space than other co-occurring organisms.展开更多
The Yining Block is located in the southwestern part of the Central Asian Orogenic Belt （CAOB）,which is characterized by widespread Carboniferous volcanic rocks.Recently,we carried out the National Nature Science Fo...The Yining Block is located in the southwestern part of the Central Asian Orogenic Belt （CAOB）,which is characterized by widespread Carboniferous volcanic rocks.Recently,we carried out the National Nature Science Foundation of China （No.41273033） and Special Fund for Basic Scientific Research of Central Colleges （No.310827153407） project,and focused on two suits volcanic rocks from the Early Carboniferous Dahalajunshan Formation and the Late Carboniferous Yishijilike Formation.Field observations,zircon U-Pb dating,and Sr-Nd isotopic dating were conducted to evaluate the petrogenesis.展开更多
Numeral Permian mafic-ultramafic complexes occur in the Beishan terrane atthe northeastern margin of the Tarim craton,southwestern Central Asian Orogenic Belt,including the Pobei,Cantoushan,Bijiashan,Hongshishan,Xuanw...Numeral Permian mafic-ultramafic complexes occur in the Beishan terrane atthe northeastern margin of the Tarim craton,southwestern Central Asian Orogenic Belt,including the Pobei,Cantoushan,Bijiashan,Hongshishan,Xuanwoling,Zhongposhan and Luodong etc.,intrusions(Qin et al.,2011;Zhang et al.,2017;Xue et al.,2018).These Beishan mafic-ultramafic complexes are composed of peridotite,pyroxenite.展开更多
Deposits of 10 volcanic events of 6 stages have been discovered by the authors after detailed field and lab studies of the Benxi and Taiyuan Formations in Shandong Province and its adjacent regions. They show certain ...Deposits of 10 volcanic events of 6 stages have been discovered by the authors after detailed field and lab studies of the Benxi and Taiyuan Formations in Shandong Province and its adjacent regions. They show certain temporal-spatial distribution characteristics. Volcanic fragments were probably derived from two different volcanic sources north and south of the North China Platform, while the magma of the two volcanic sources was probably derived from the lower crust. A new stratigraphic correlation scheme is put forward for the Benxi and Taiyuan Formations in this region on the basis of previous biostratigraphic work with the regionally widespread volcanic event layers as the marker bed for the isochronous stratigraphic correlation on a super-regional scale and in conjunction with the maximum transgressive event layers.展开更多
Objective Though the Central Asian Orogenic Belt (CAOB) is characterized by widespread Phanerozoic crustal growth,there is little juvenile crust documented in its southeastern segment,northern margin of the North Chin...Objective Though the Central Asian Orogenic Belt (CAOB) is characterized by widespread Phanerozoic crustal growth,there is little juvenile crust documented in its southeastern segment,northern margin of the North China Craton(NCC)(Zhang et al,2007,2009).Late Carboniferous Dongwanzi ultramafic-mafic cumulate complex occurs in northern margin of the NCC and is intruded by a syenite with depleted Sr-Nd isotopes (Ma et al.,2014).However,the age and petrogenesis of this syenite is poorly constrained.In this study,we present new petrological,zircon U-Pb and Hf isotopic data of the Dongwanzi syenite,in order to put insights on its formation age and petrogenetic relationship with cumulates.展开更多
China is rich in Middle and Carboniferous fossil corals. The coral faunas in different regions have varying characteristics and can be divided into distinct assemblages. The coral fauna in South China is dominated by ...China is rich in Middle and Carboniferous fossil corals. The coral faunas in different regions have varying characteristics and can be divided into distinct assemblages. The coral fauna in South China is dominated by the order Caninida and contains numerous endemic elements; that in North China has a lot of Middle Carboniferous corals which are monotonous in species, with Late Carboniferous solitary corals being predominant. The coral fauna in Junggar mainly contains large bi-zoned solitary caninids, while that in southern Khingan is similar to that in South China due to the presence of abundant tri-zoned compound corals. In northern Tibet the coral fauna is also similar to that in South China, but in southern Tibet it is of a cold-water type. Therefore, the Middle and Late Carboniferous coral geography of China can be divided into the Tethys, Boreal and Gondwana Realms.展开更多
In early Late Carboniferous only the South Junggaru-Bogeda area of the ancient North Xinjiang geosynclinal region was still in the geosynclinal stage,when it was the critical Period for closing of the geosynclinal reg...In early Late Carboniferous only the South Junggaru-Bogeda area of the ancient North Xinjiang geosynclinal region was still in the geosynclinal stage,when it was the critical Period for closing of the geosynclinal region. The crust movement was in a special form with frequent rhythm,and there developed a typical flysch formation in Liushugou-Urho in Late Carboniferous. A thorough investigation and study on the flysch formation have been carried out,based on a great number of the firsthand field information and experiment analytical data.The Late Carboniferous flysch formation in Liushugou-Urho,Xinjiang,formed in the Bashkirian .consisting mainly of the Baogutu Formation. There are outcrops if the flysch at Liushugou ,Kesongertai, Kayinte, Hatu, Dongfeng Wudui, Urho, etc. The outcrops at Kesongertai and Urho, 422m and 1228m thick respectively,are more typical and complete flysch formation.The Late Carbonilerous flysch formation in Liushugou-Urho consists mainly of the rhythmic series of sandstone and shale. The shale (or mudstone) component increases southeastward to Urho and sandstone component increases southwestward to Liushugou-Kayinte. Body fossils are seldom in the formation but the Nereites ichnofacies are common. The distribution of trace elements is stable and belongs to the regular pattern. THe flysch formation at the Urho formed chiefly in a bathyal sedimentary environment,possessing a complete transgressive-and-regressive sequence. At Liushugou -Kayinte, the formation can obviously be divided into the upper and lower parts. The upper formed in a littoral-neritic oscillatory environment,while the lower deposited in a bathyal turbidite basin. The two parts constitute a transgressive sequence.展开更多
The Wupata'erkan Group, also called Wupata'erkan Formation, distributed in the South Tianshan, Xinjiang, China, mainly consists of gray and dark gray fine-grained clastic rocks, interlayered with volcanic rock...The Wupata'erkan Group, also called Wupata'erkan Formation, distributed in the South Tianshan, Xinjiang, China, mainly consists of gray and dark gray fine-grained clastic rocks, interlayered with volcanic rocks, carbonates and cherts. Some ultra-basic rocks (blocks) punctuate the formation. The formation was variously assigned to Silurian-Middle Devonian, Silurian-Lower Devonian, and pre-Devonian, mainly based on Atrypa bodini Mansuy, Hypothyridina parallelepipedia (Brour.) and Prismatophyllum hexagonum Yoh collected from the limestone interlayers, respectively. However, radiolarian fossils obtained from 24 chert specimens of the Wupata'erkan Group, mainly include Albaillella sp. cf. A. undulata Deflandre, Albaillella sp. cf. A. paradoxa Deflandre, Albaillella cf. A. deflandrei Gourmelon, Albaillella sp. cf. A. indensis Won, Albaillella sp. cf. A. excelsa Ishiga, Kito and Imoto, Albaillella sp. and Latentifistulidae gen. et. sp. indet., are earliest Carboniferous and Late Permian. The earliest Carboniferous assemblage is characterized by Albaillella sp. cf. A. undulata Deflandre, Albaillella sp. cf. A. paradoxa Deflandre, Albaillella cf. A. deflandrei Gourmelon and Albaillella sp. cf. A. indensis Won, and the Late Permian assemblage by Albaillella sp. cf. A. excelsa Ishiga, Kito and Imoto. This new stratigraphic evidence indicates that the Wupata'erkan Group is possibly composed of rocks with different ages from Silurian to Permian, and therefore, it is probably an ophiolite melange. The discovery of Late Permian Albaillella sp. cf. A. excelsa provides more reliable evidence supporting the existence of a Permian relic ancient oceanic basin in the western part of Xinjiang South Tianshan.展开更多
Results of a systematic paleomagnetic study are reported based on Late Carboniferous to Early Permian sedimentary rocks on the north slope of the Tanggula Mountains, in the northern Qiangtang terrane （NQT）, Tibet, C...Results of a systematic paleomagnetic study are reported based on Late Carboniferous to Early Permian sedimentary rocks on the north slope of the Tanggula Mountains, in the northern Qiangtang terrane （NQT）, Tibet, China. Data revealed that magnetic minerals in limestone samples from the Zarigen Formation （CP^z）are primarily composed of magnetite, while those in sandstone samples from the Nuoribagaribao Formation （Pnr） are dominated by hematite alone, or hematite and magnetite in combination. Progressive thermal, or alternating field, demagnetization allowed us to isolate a stable high temperature component （HTC） in 127 specimens from 16 sites which successfully passed the conglomerate test, consistent with primary remnance. The tilt-corrected mean direction for Late Carboniferous to Early Permian rocks in the northern Qiangtang terrane is D°=30.2°, Is=-40.9°, ks=269.0, a95=2.3°, N=16, which yields a corresponding paleomagnetic pole at 25.7°N, 241.5°E （alp/rim=2.8°/1.7°）, and a paleolatitude of 23.4°S. Our results, together with previously reported paleomagnetic data, indicate that： （1） the NQT in Tibet, China, was located at a low latitude in the southern hemisphere, and may have belonged to the northern margin of Gondwana during the Late Carboniferous to Early Permian; （2） the Paleo-Tethys Ocean was large during the Late Carboniferous to Early Permian, and （3） the NQT subsequently moved rapidly northwards, perhaps related to the fact that the Paleo-Tethys Ocean was rapidly contracting from the Late Permian to Late Triassic while the Bangong Lake-Nujiang Ocean, the northern branch of the Neo-Tethys Ocean, expanded rapidly during this time.展开更多
Various microbial fabrics characterize late Moscovian mounds in Houchang Town,southern Guizhou,South China.The dominant components of the mounds are microbial boundstones with stromatolitic structures,irregular oncoid...Various microbial fabrics characterize late Moscovian mounds in Houchang Town,southern Guizhou,South China.The dominant components of the mounds are microbial boundstones with stromatolitic structures,irregular oncoid-like forms,and wrinkle structures.Calcimicrobes recognized in the mounds include Girvanella,Ortonella,Wetheredella-like,Palaeomicrocodium-like,and some problematic calcimicrobes occurring in deposits between microbial boundstones,in thrombolitic textures,and in some intraclasts.Microbial carbonates are common in the substrate and interior of the mounds,including thrombolitic textures,microstromatolites,microbial ooids,oncoids,irregular encrusted layers,microbial mat debris,and microbial micrite.Calcimicrobes and microbial carbonates played an important role in the construction of the mounds:Girvanella might have contributed as a source of lime mud that formed the mound and stabilized the coral frame;thrombolitic mats could trap and fix sediments and bioclasts,contributing to the stabilization of substrate and mound limestones;and,microbial boundstone,clotted micrite and micritized bioclast could provide a hard substrate for encrusting metazoans(e.g.,bryozoans,Ivanovia).The abundant microbial fabrics in the mounds indicate that microbial activity was widespread in Moscovian reef mounds in southern Guizhou,and this suggests that microbial organisms were the primary mound builders in the study area.展开更多
Based upon the research materials from Shanxi, Hebei, Henan, Jiangsu, Shan- dong, Anhui and Shaanxi provinces, the Late Carboniferous fusulinid biostrati- graphical sequence in stratigraphical region of North China ca...Based upon the research materials from Shanxi, Hebei, Henan, Jiangsu, Shan- dong, Anhui and Shaanxi provinces, the Late Carboniferous fusulinid biostrati- graphical sequence in stratigraphical region of North China can be subdivided from bottom upwards into the following zones.展开更多
基金This study is supported by a grant （No. 40572014） from National Science Foundation of China （NFSC）.
文摘Phylloid algae arc important rcef-builders in the late Carboniferous. This paper focuses on the paleoecology of phylloid algae in the Late Carboniferous on well-exposed reefs in Ziyun County, Guizhou Province. Phylloid algae growing closely packed arc attached via holdfast or similar structure to substrate. They were growing in environments such as shallow water, photic zone and below the wave base with medium energy currents. They have a variety of morphological forms, such as single cup-shaped, cabbage-shaped and clustering cup-shaped. The thalli arc of certain tenacity and intensity. In the areas dominated by phylloid algae, other marine orgam＇sms arc relatively scarce. Obviously, phylloid algae arc stronger competitors for living space than other co-occurring organisms.
文摘The Yining Block is located in the southwestern part of the Central Asian Orogenic Belt （CAOB）,which is characterized by widespread Carboniferous volcanic rocks.Recently,we carried out the National Nature Science Foundation of China （No.41273033） and Special Fund for Basic Scientific Research of Central Colleges （No.310827153407） project,and focused on two suits volcanic rocks from the Early Carboniferous Dahalajunshan Formation and the Late Carboniferous Yishijilike Formation.Field observations,zircon U-Pb dating,and Sr-Nd isotopic dating were conducted to evaluate the petrogenesis.
基金supported financially by the NSFC projects(Grant Nos.U1403291,41802074,41830216,41202044)projects of the China Geological Survey(Grant Nos.1212010811033,12120113096500,12120113094000,DD20160123,DD20160009 and DD20179607)+1 种基金the IGCP 662 projectDDE.
文摘Numeral Permian mafic-ultramafic complexes occur in the Beishan terrane atthe northeastern margin of the Tarim craton,southwestern Central Asian Orogenic Belt,including the Pobei,Cantoushan,Bijiashan,Hongshishan,Xuanwoling,Zhongposhan and Luodong etc.,intrusions(Qin et al.,2011;Zhang et al.,2017;Xue et al.,2018).These Beishan mafic-ultramafic complexes are composed of peridotite,pyroxenite.
基金This study was supported by the National Natural Science Foundation of China Grant No. 4880102
文摘Deposits of 10 volcanic events of 6 stages have been discovered by the authors after detailed field and lab studies of the Benxi and Taiyuan Formations in Shandong Province and its adjacent regions. They show certain temporal-spatial distribution characteristics. Volcanic fragments were probably derived from two different volcanic sources north and south of the North China Platform, while the magma of the two volcanic sources was probably derived from the lower crust. A new stratigraphic correlation scheme is put forward for the Benxi and Taiyuan Formations in this region on the basis of previous biostratigraphic work with the regionally widespread volcanic event layers as the marker bed for the isochronous stratigraphic correlation on a super-regional scale and in conjunction with the maximum transgressive event layers.
基金supported by the National Science Foundation of China(grants 41302042 and 41672217)the Fundamental Research Funds for the Central Universities(grants N170104022).
文摘Objective Though the Central Asian Orogenic Belt (CAOB) is characterized by widespread Phanerozoic crustal growth,there is little juvenile crust documented in its southeastern segment,northern margin of the North China Craton(NCC)(Zhang et al,2007,2009).Late Carboniferous Dongwanzi ultramafic-mafic cumulate complex occurs in northern margin of the NCC and is intruded by a syenite with depleted Sr-Nd isotopes (Ma et al.,2014).However,the age and petrogenesis of this syenite is poorly constrained.In this study,we present new petrological,zircon U-Pb and Hf isotopic data of the Dongwanzi syenite,in order to put insights on its formation age and petrogenetic relationship with cumulates.
文摘China is rich in Middle and Carboniferous fossil corals. The coral faunas in different regions have varying characteristics and can be divided into distinct assemblages. The coral fauna in South China is dominated by the order Caninida and contains numerous endemic elements; that in North China has a lot of Middle Carboniferous corals which are monotonous in species, with Late Carboniferous solitary corals being predominant. The coral fauna in Junggar mainly contains large bi-zoned solitary caninids, while that in southern Khingan is similar to that in South China due to the presence of abundant tri-zoned compound corals. In northern Tibet the coral fauna is also similar to that in South China, but in southern Tibet it is of a cold-water type. Therefore, the Middle and Late Carboniferous coral geography of China can be divided into the Tethys, Boreal and Gondwana Realms.
文摘In early Late Carboniferous only the South Junggaru-Bogeda area of the ancient North Xinjiang geosynclinal region was still in the geosynclinal stage,when it was the critical Period for closing of the geosynclinal region. The crust movement was in a special form with frequent rhythm,and there developed a typical flysch formation in Liushugou-Urho in Late Carboniferous. A thorough investigation and study on the flysch formation have been carried out,based on a great number of the firsthand field information and experiment analytical data.The Late Carboniferous flysch formation in Liushugou-Urho,Xinjiang,formed in the Bashkirian .consisting mainly of the Baogutu Formation. There are outcrops if the flysch at Liushugou ,Kesongertai, Kayinte, Hatu, Dongfeng Wudui, Urho, etc. The outcrops at Kesongertai and Urho, 422m and 1228m thick respectively,are more typical and complete flysch formation.The Late Carbonilerous flysch formation in Liushugou-Urho consists mainly of the rhythmic series of sandstone and shale. The shale (or mudstone) component increases southeastward to Urho and sandstone component increases southwestward to Liushugou-Kayinte. Body fossils are seldom in the formation but the Nereites ichnofacies are common. The distribution of trace elements is stable and belongs to the regular pattern. THe flysch formation at the Urho formed chiefly in a bathyal sedimentary environment,possessing a complete transgressive-and-regressive sequence. At Liushugou -Kayinte, the formation can obviously be divided into the upper and lower parts. The upper formed in a littoral-neritic oscillatory environment,while the lower deposited in a bathyal turbidite basin. The two parts constitute a transgressive sequence.
基金the National Natural Science Foundation of China(Grant 40072077) the Tarim Oil Field Company.PetroChina(Grant 2098050230).
文摘The Wupata'erkan Group, also called Wupata'erkan Formation, distributed in the South Tianshan, Xinjiang, China, mainly consists of gray and dark gray fine-grained clastic rocks, interlayered with volcanic rocks, carbonates and cherts. Some ultra-basic rocks (blocks) punctuate the formation. The formation was variously assigned to Silurian-Middle Devonian, Silurian-Lower Devonian, and pre-Devonian, mainly based on Atrypa bodini Mansuy, Hypothyridina parallelepipedia (Brour.) and Prismatophyllum hexagonum Yoh collected from the limestone interlayers, respectively. However, radiolarian fossils obtained from 24 chert specimens of the Wupata'erkan Group, mainly include Albaillella sp. cf. A. undulata Deflandre, Albaillella sp. cf. A. paradoxa Deflandre, Albaillella cf. A. deflandrei Gourmelon, Albaillella sp. cf. A. indensis Won, Albaillella sp. cf. A. excelsa Ishiga, Kito and Imoto, Albaillella sp. and Latentifistulidae gen. et. sp. indet., are earliest Carboniferous and Late Permian. The earliest Carboniferous assemblage is characterized by Albaillella sp. cf. A. undulata Deflandre, Albaillella sp. cf. A. paradoxa Deflandre, Albaillella cf. A. deflandrei Gourmelon and Albaillella sp. cf. A. indensis Won, and the Late Permian assemblage by Albaillella sp. cf. A. excelsa Ishiga, Kito and Imoto. This new stratigraphic evidence indicates that the Wupata'erkan Group is possibly composed of rocks with different ages from Silurian to Permian, and therefore, it is probably an ophiolite melange. The discovery of Late Permian Albaillella sp. cf. A. excelsa provides more reliable evidence supporting the existence of a Permian relic ancient oceanic basin in the western part of Xinjiang South Tianshan.
基金supported by the National Natural Science Foundation of China(Grant Nos.41304049 and 41421002)the Special Fund for Strategic Pilot Technology of the Chinese Academy of Sciences(Grant No. XDB03010000)
文摘Results of a systematic paleomagnetic study are reported based on Late Carboniferous to Early Permian sedimentary rocks on the north slope of the Tanggula Mountains, in the northern Qiangtang terrane （NQT）, Tibet, China. Data revealed that magnetic minerals in limestone samples from the Zarigen Formation （CP^z）are primarily composed of magnetite, while those in sandstone samples from the Nuoribagaribao Formation （Pnr） are dominated by hematite alone, or hematite and magnetite in combination. Progressive thermal, or alternating field, demagnetization allowed us to isolate a stable high temperature component （HTC） in 127 specimens from 16 sites which successfully passed the conglomerate test, consistent with primary remnance. The tilt-corrected mean direction for Late Carboniferous to Early Permian rocks in the northern Qiangtang terrane is D°=30.2°, Is=-40.9°, ks=269.0, a95=2.3°, N=16, which yields a corresponding paleomagnetic pole at 25.7°N, 241.5°E （alp/rim=2.8°/1.7°）, and a paleolatitude of 23.4°S. Our results, together with previously reported paleomagnetic data, indicate that： （1） the NQT in Tibet, China, was located at a low latitude in the southern hemisphere, and may have belonged to the northern margin of Gondwana during the Late Carboniferous to Early Permian; （2） the Paleo-Tethys Ocean was large during the Late Carboniferous to Early Permian, and （3） the NQT subsequently moved rapidly northwards, perhaps related to the fact that the Paleo-Tethys Ocean was rapidly contracting from the Late Permian to Late Triassic while the Bangong Lake-Nujiang Ocean, the northern branch of the Neo-Tethys Ocean, expanded rapidly during this time.
基金supported by the National Natural Science Foundation of China(Grant No.41572004)
文摘Various microbial fabrics characterize late Moscovian mounds in Houchang Town,southern Guizhou,South China.The dominant components of the mounds are microbial boundstones with stromatolitic structures,irregular oncoid-like forms,and wrinkle structures.Calcimicrobes recognized in the mounds include Girvanella,Ortonella,Wetheredella-like,Palaeomicrocodium-like,and some problematic calcimicrobes occurring in deposits between microbial boundstones,in thrombolitic textures,and in some intraclasts.Microbial carbonates are common in the substrate and interior of the mounds,including thrombolitic textures,microstromatolites,microbial ooids,oncoids,irregular encrusted layers,microbial mat debris,and microbial micrite.Calcimicrobes and microbial carbonates played an important role in the construction of the mounds:Girvanella might have contributed as a source of lime mud that formed the mound and stabilized the coral frame;thrombolitic mats could trap and fix sediments and bioclasts,contributing to the stabilization of substrate and mound limestones;and,microbial boundstone,clotted micrite and micritized bioclast could provide a hard substrate for encrusting metazoans(e.g.,bryozoans,Ivanovia).The abundant microbial fabrics in the mounds indicate that microbial activity was widespread in Moscovian reef mounds in southern Guizhou,and this suggests that microbial organisms were the primary mound builders in the study area.
文摘Based upon the research materials from Shanxi, Hebei, Henan, Jiangsu, Shan- dong, Anhui and Shaanxi provinces, the Late Carboniferous fusulinid biostrati- graphical sequence in stratigraphical region of North China can be subdivided from bottom upwards into the following zones.
