检索结果-南通市图书馆

The Upper Devonian orbital cyclostratigraphy and numerical dating conodont zones from Guangxi,South china

在线全文

学校读者我要写书评

暂无评论

Science china earth sciences 2005年第1期48卷 32-41页

作者： gong yiming, XU Ran, TANG Zhongdao & LI Baohua faculty of earth Science, china university of geosciences, wuhan 430074, china Laboratory of Marine Geology, Tongji university, Shanghai 200092, china faculty of earth Science China University of Geosciences Wuhan China Laboratory of Marine Geology Tongji University Shanghai China

The hierarchically organized laminae, bundles, bundlesets and superbundlesets which correspond to a sub-Milankovitch, obliquity or precession, eccentricity and long eccentricity cyclothems, respectively, have been distinguished from the Upper Devonian Fras-nian-Famennian (F-F) transitional carbonate successions deposited in the carbonate-basin and slope facies of Guangxi, South china. The durations of cyclothems are 8000-10000a, 16667a or 33333a, 100000a and 400000a, respectively. The ratio of eccentricity to precession, eccentricity to obliquity, and long eccentricity to eccentricity is 1 : 6, 1 : 3 and 1 : 4 in the Devonian, respectively. Orbital cyclostratigraphical studies show that the durations of the conodont falsio-valis Zone, transitans Zone, punctate Zone, Lower hassi Zone, Upper hassi Zone, jamieae Zone, Lower rhenana Zone, Upper rhenana Zone, linguiformis Zone, Lower triangularis Zone, Middle triangularis Zone and Upper triangularis Zone are 0.4, 0.4, 0.4, 0.3, 0.4, 0.2, 0.8, 0.6, 0.8, 0.3, 0.3 and 0.3 Ma from bottom to top, respectively, and the duration of the Frasnian is 4.3 Ma. The conodont is the normal marine organism of the latest mass extinction (the latest linguiformis Zone) and the first recovery (including the whole Lower triangularis and Middle triangularis Zone) in the F-F transition. The conodont mass extinction and recovery lasted 200000-100000a and 0.6 Ma, respectively. We consider that average durations of the fossil zones calculated by reported numerical ages divided by fossil zone numbers within a stage or series or system cannot discovery complications and non-uniformity of evolutionary organisms and environments.

关键词： orbital cyclostratigraphy, conodont zone, numerical dating, mass extinction, Devonian, Guangxi, South china.

Silurian Seismites in Hanxia,Yumen,North Qilian Mountains,and Their Tectonic Significance

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2001年第4期75卷 385-390页

作者： DU Yuansheng, gong Shuyun, HAN Xin, WANG Jiasheng, GU Songzhuand LIN Wenjiao faculty of earth sciences, china university of geosciences, wuhan 430074, Hubei china Univ Geosci Fac Earth Sci Wuhan 430074 Peoples R China

The Caledonian orogenic belt of the North Qilian Mountains is an intensely active structure belt. In the process of the Late Caledonian syn-orogeny, the North Qilian-Hexi Corridor area was situated on the tectonic background of a syn-orogenic basin. In response to the orogenic process of the North Qilian Mountains, typical earthquake event deposits—seismites of the Silurian were widely distributed around Hanxia of Yumen City, the Liyuan River of Sunan County and Biandukou of Minle County. In the Hanxia area, where seismites are typically developed, clastic deposits of tidal-flat facies are the background deposits of the Hanxia Formation. The earthquake event deposits are characterized by sandy mudstone veins, synsedimentary microfractures, micro-corrugated laminations and earthquake breccias, which in turn constitute complex seismites, featuring seismic corrugation, shattering and liquefied sandy mudstone veins, auto-clastic breccias and intraclastic parabreccias. The seismites and tidal flat deposits formed typical sequences of earthquake event deposits.

关键词： Gansu Province North Qilian orogenic belt Caledonian Stage Silurian seismites earthquake event deposits

On Evolutionary Sequence Systematics: Taking Permian Waagenophylloid Coral Fauna as an Example

在线全文

学校读者我要写书评

暂无评论

Journal of earth Science 1999年第3期18卷 215-227页

作者： Xu Guirong gong Shuyun Wang Yongbiao(faculty of earth sciences, china university of geosciences, wuhan 430074) faculty of earth sciences China University of Geosciences Wuhan 430074

Evolutionary sequence systematics is a discipline in paleontology and biology that deals with phylogeny of organism, the main purpose of which is to understand relatives between species and taxa and to show their evolutionary sequence. The systematics is set up on the phenetic-cladistic systematics. A number of important theoretical concepts in the cladistics are added the concept of time in the systematics. For example, the time-span between the closest sister species is considered limited in the duration of their mother species. The foundational methodology of the systematics is to analyze sister-group and character mosaic distribution, and the key to study evolutionary sequence is to understand cbaracter mosaic distribution fully. These aualyses can be executed by using computer. In the paper, the Permian Waagenophylloid coral fauna is taken as an example to illustrate the analysis on evolutionary sequence. These coral fossils are widespread in Tethyan *** characters and a number of cbaracter states for each character used in study result from features of Waagenophylloid corals. According to principles of tbe widest distribution of character states, fossil records and ontogenesis we discerned plesiomorph character states for each character. Characters are divided into 4 ranks on the basis of their important place in pkylogeny. Based on the theory and methopology of tbe evolutionary sequence systematics the paper analyzes the sister groups and evolutionary sequence. In the examination each other between the analyses of sister groups and evolutionary sequence tbe paper found many importunt phenomena of paleontology,such as character degeneration, parallel evolution, and polydirectional clades, and distinguished a number of abnormal order. Iu the discussion to test tke rirst occurrence event8 of biostratigraphy we infer the Possible stratigraphic levels of some fossils.

关键词： evolutionary sequence systematics character mosaic distribution Permian Waagenophylloid corals

Devonian Sequence Stratigraphy and Sea Level Change Cycles in South china

在线全文

学校读者我要写书评

暂无评论

Journal of earth Science 1996年第1期15卷 72-79页

作者： Du Yuansheng gong yiming (faculty of earth sciences, china university of geosciences, wuhan 430074) Wu Yi (Guangxi Institute of Geology, Nanning 530023) Liu Benpei Feng Qinglai (faculty of earth sciences, china university of geosciences, wuhan 430074)

The Devonian is well developed in South china and has drawn a great attention from the geologists both at domestic and abroad. On the basis of study on the sequence stratigraphy in more than 10 sections in Guizhou, Guangxi, Longmenshan and Southern Qinling within South china we have identified 21 sequences and T-R cycles that correspond to third-order sea level changes. These sea level change cycles were controlled by autorhythm(Pragian,Eifelian), allorhythm(Lochkovian,Emsian,Givetian) and coupling rhythm mechanisms (frasian, Famennian and F-F boundary).

关键词： south china Devonian,sequence,sea level change cycle.

earthquake-controlled event deposits and its tectonic significance from the Middle Permian Wandrawandian Siltstone in the Sydney Basin, Australia

在线全文

学校读者我要写书评

暂无评论

Science china earth sciences 2005年第9期48卷 1337-1346页

作者： DU Yuansheng1, G. R. Shi1,2 & gong yiming1 1. faculty of earth sciences, china university of geosciences, wuhan 430074, china 2. School of Ecology and Environment, Deakin university, Victoria 3125, Australia faculty of earth sciences China University of Geosciences Wuhan China School of Ecology and Environment Deakin University Victoria Australia

The Sydney-Bowen basin in eastern Australia is an elongate back arc-converted foreland basin system situated between the Lachlan Fold Belt in the west and the New England Fold Belt in the east. The Middle Permian Wandrawandian Siltstone at Warden Head near Ulla- dulla in the southern Sydney Basin is dominated by fossiliferous siltstone and mudstone, with a large amount of dropstones and minor pebbly sandstone beds. Two general types of deposits are recognized from the siltstone unit in view of the timing and mechanism of formation. One is rep- resented by the primary deposits from offshore to subtidal environments with abundant drop- stones of glacial marine origin. The second type is distinguished by secondary, soft-sediment deformational deposits and structures, and comprises three layers of mudstone dykes of seismic origin. In the latter type, metre scale, laterally extensive syn-depositional slump deformation structures occur in the middle part of the Wandrawandian Siltstone. The deformation structures vary in morphology and pattern, including large-scale complex-type folds, flexural stratification, concave-up structures, faulting of small displacements accompanied by folding and brecciation. The slumps and associated syn-sedimentary structures are attributed to penecontemporaneous deformations of soft sediments (mostly silty mud) formed as a result of mass movement of un- consolidated and/or semi-consolidated substrate following an earthquake event. The occurrence of the earthquake event deposits supports the current view that the Sydney Basin was located in a back-arc setting near the New England magmatic arc on an active continental margin during the Middle Permian.

关键词： Permian, seismites, earthquake, tectonics, Sydney Basin, Australia.

FROM BACK-ARC BASIN TO BACK-ARC FORELAND BASIN—THE SEDIMENTARY BASIN AND TECTONIC EVOLUTION OF THE LATE CALEDONIAN—EARLY HERCYNIAN STAGES IN CORRIDOR AND NORTH QILIAN MTS

在线全文

学校读者我要写书评

暂无评论

地学前缘 2000年第S1期7卷 252-253页

作者： Du Yuansheng, gong Shuyun, Han Xin, Wang Jiasheng, Hou Guangjiu(faculty of earth sciences, china university of geosciences, wuhan 430074,china)

Qilian orogenic belt is a typical orogenic belt formed by polycyclic collisions between the North china plate and Qaidam microplate. Qilian ocean originated from the rift of the late Proterozoic Rodinia continent(Pangea\|850), evolved through rift basin and became an archipelagic ocean in the Caledonian stage. The Lower Proterozoic strata in Qilian area are mid\|high\|rank metamorphic rocks that constitute the metamorphic basement of the area. The “Huangyuan Movement" (in South Qilian and Central Qilian) and "Alashan Movement" (in North Qilian) in the latest Late Proterozoic formed a regional unconformity. The middle Proterozoic in the area are mudstones and carbonate rocks with stromatolites and ooids. The Qingbaikou System of the upper Proterozoic in the North Qilian and Corridor region is also mudstone and carbonate rock with stromatolites. The Qingbaikou System in Central Qilian is sandstones and mudstones. There are alkaline and tholeiite in the Sinian System in North Qilian and Corridor. The contact between Qingbaikou System and Sinian System is a regional unconformity (Quanji Movement). Qilian ocean began to rift away in Caledonian tectonic stage on the Pre\|Sinian basement.

关键词： sedimentary basin tectonic evolution late Caledon ian early Hercynian North Qilian Mts. Corridor

Devonian Frasnian-Famennian Transitional Milankovitch Cycles and High-Resolution Stratigraphic Correlation

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2001年第4期75卷 354-363页

作者： gong yiming faculty of earth Science, china university of geosciences, wuhan, 430074LI Baohua Laboratory of Marine Geology, Tongji university, Shanghai 200092and WU Yi Guangxi Institute of Geology, Nanning 530023 china Univ Geosci Fac Earth Sci Wuhan 430074 Peoples R China Tongji Univ Lab Marine Geol Shanghai 200092 Peoples R China Guangxi Inst Geol Nanning 530023 Peoples R China

Four hierarchical cyclothems, superbundlesets, bundlesets, bundles and laminae, have been identified from the Devonian Frasnian-Famennian carbonate strata in Guangxi, South china. Their hierarchical structures, ratio relationships and sequence in conodont zones are continuous and stable and can be traced across different facies zones and sedimentary basins. Our data show that hierarchically organized superbundlesets, bundlesets, bundles and laminae correspond to the long eccentricity, eccentricity, obliquity or precession and sub-Milankovitch cycles respectively. Their periods were 400,000, 100,000, 33,333, 16,667 and 8,000–17,000 a, respectively. The ratios of long eccentricity to eccentricity, eccentricity to obliquity, and eccentricity to precession in the Devonian are 1:4, 1:3 and 1:6 respectively. Using these hierarchical Milankovitch cyclothems, chronostratigraphical division and correlation can be realized at a resolution of 100 ka or 10 ka at the Frasnian-Famennian transition. The time intervals of the Upper rhenana Zone, linguiformis Zone, and the Lower, Middle and Upper triangularis Zone are 0.6, 0.8, 0.3, 0.3 and 0.3 Ma, respectively. Sea-level changes of the Frasnian-Famennian transition were not coherent and synchronous at the resolution of 100 ka or 10 ka in the basin-slope carbonate sequences of Guangxi, South china.

关键词： Milankovitch cycle high-resolution stratigraphic correlation sea-level change numerical dating Devonian Guangxi South china

Devonian Sea-Level Change Rhythms in South china and Coupling Relationships Among the earth-spheres

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1997年第4期71卷 370-385页

作者： gong yiming,faculty of earth Science, china university of geosciences, wuhan,Hubei, 430074Wu Yi,Guangxi Institute of Geology, Nanning, GuangxiDu Yuansheng, Feng Qinglai and Liu Benpeichina university of geosciences, wuhan, Hubei, 430074 faculty of earth Science China University of Geosciences Wuhan Hubei 430074 Guangxi Institute of Geology Naming Guangxi china university of geosciences Wuhan Hubei 430074 [?]gong yiming Born in October 1958 graduated from the Department of Geology Wuhan College of Geology in 1981 received his Ph.D. degree in china university of geosciences (wuhan) in 1991. He is now a professor of that university and mainly engaged in sedimentary geology of Chinese orogenic belts ichnology (trace fossils) and sequence stratigraphy.

Twenty orthosequences and their corresponding sea-level change (SLC) cycles have been recognized in the Devonian overlying the Caledonian unconformity, of which 9, 5.5 and 5.5 occurred in the Lower, Middle and Upper Devonian respectively. They can be grouped into 4 orthosequence sets, in which the maximum flooding surfaces lie in the sulcutus Zone (D12), perbonus Zone (D13), Middle and Upper varcus Zone (D22) and gigas Zone (D21) respectively. Four instant palaeogeographical reconstructions of South china have been made in the Emsian and Givetian. Devonian sea-level change rhythms of South china can be divided into 3 categories: the autorhythmic, the worldwide and regional allorhythmic, and the coupling-rhythmic. They developed respectively in the Famennian, Pragian, Eifelian, Lochkovian, Emsian, Givetian, Frasnian and the F / F (between the Frasnian and Famennian) event. The cause of the worldwide allorhythmic SLC of the Pragian and Eifelian under comparatively dry, warm and tranquil conditions may be related to the pulsating expanding and contracting of the oceanic basin volume or the earth volume pulsation, rather than the common glaciation and plate tectonism. The coupling-rhythmic SLC related to the F/ F event is a sensitive indicator of the interaction between terrestrial and extraterrestrial factors, and coordinated action among the earth-spheres.

关键词： sequence stratigraphy sea-level change rhythm coupling among the earth-spheres instant palaeogeographical reconstruction Devonian South china

Relationships between bacterial-algal proliferating and mass extinction in the Late Devonian Frasnian-Famennian transition:Enlightening from carbon isotopes and molecular fossils

在线全文

学校读者我要写书评

暂无评论

Science china earth sciences 2005年第10期48卷 1656-1665页

作者： gong yiming1,2, XU Ran1, TANG Zhongdao1, SI Yuanlan3 & LI Baohua4 1. faculty of earth Science and State Key Laboratory of Geological Processes and Mineral Resources, china university of geosciences, wuhan 430074, china 2. Institute of Resources & Environments, Henan Polytechnic university, Jiaozuo 454003, china 3. Department of Computer Science, South-Central university for Nationalities, wuhan 430074, china 4. Laboratory of Marine Geology, Tongji university, Shanghai 200092, china china university of geosciences Henan Polytechnic university South-Central university for Nationalities Tongji university

Studies show positive shifts of inorganic and organic carbon isotope values (δ 13Ccarb and δ 13Ckerogen) from +0.43 (‰ V-PDB) to +3.54 (‰ V-PDB) and from ?29.38 (‰ V-PDB) to ?24.14 (‰ V-PDB), respectively, B* (Ba* = Ba/ (Al2O3 X 15%)) values from 0.015 to 0.144, TOC values from 0.02% to 0.21%, V/Cr values from 0.3 to 2.0, Sr/Ba values from 3.20 to 49.50 in the Late Devonian Frasnian Upper rhenana zone to the top linguiformis zone of the Yangdi sec-tion deposited in carbonate slope facies of Guilin, Guangxi, South china, which indicates that biomass, productivity, organic carbon burial and salinity increase and that oxygenation near the boundary between sediments and waters decreases from the Late Devonian Frasnian Upper rhenana zone to the top linguiformis zone. Abundance of molecular fossils increases and normal alkanes, isoprenoid hydrocarbon, terpanes and steranes are dominated from the Late Devonian Frasnian to the bottom of Famennian, which shows that the predecessors of molecular fossils of the Frasnian-Famennian (F-F) transition are dominated by marine phytoplankton, zooplankton and benthic bacteria with no photosynthesis. Therefore, it is considered that the F-F transitional mass extinction with a multistage, selection and global synchronizing was caused by bacte-rial-algal proliferating, continuing deterioration of the shallow marine ecoenvironment of the mid-dle-lower latitudes. A simple cause and effect chain can be expressed as: appearance of seed plants and multi-storied forests → enhanced chemical and biochemical weathering and pe-dogenesis → wide development of soils → increasing riverine nutrient fluxes in epicontinental sea → from superoligotrophic to eutrophic in epicontinental sea → proliferating of marine phyto-plankton and zooplankton → frequent red tide and anoxia → mass extinction of shallow marine organisms in the middle-lower latitudes. It is worth notice that the factor drawdown of atmos-pheric Pco2, climatic cooling and sea level falling c

关键词： mass extinction, bacteria-algae, carbon isotopes, molecular fossils, biodiversity, Late Devonian, Guangxi, South china.