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Cenozoic reactivation along the Late Triassic Ganzi-Litang suture,eastern Tibetan Plateau

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Geoscience Frontiers 2020年第3期11卷 1069-1080页

作者： W.T.Jackson Jr. D.M.Robinson A.L.Weislogel X.Jian Department of Earth Sciences University of South AlabamaMobileAL36688USA Department of Geological Sciences and Center for Sedimentary Basin Studies The University of AlabamaTuscaloosaAL35487USA Department of Geography and Geology West Virginia UniversityMorgantownWV26506USA State Key Laboratory of Marine Environmental Science College of Ocean and Earth SciencesXiamen UniversityXiamen 361102China

The spatial-temporal development of Cenozoic reactivation along Mesozoic suture zones in the Tibetan Plateau are first-order parameters needed for assessing models of plateau *** Ganzi-Litang suture,in the eastern Tibetan Plateau,developed in the Late Triassic because of subduction and closure along the eastern branch of the Paleo-Tethys *** the city of Litang,the Ganzi-Litang suture is defined by a melange sequence with faultbound,synorogenic nonmarine strata along the western and eastern flanks,suggesting post-Triassic structural *** present detrital zircon U-Pb geochronology and field data to determine the timing and style of reactivation along the Ganzi-Litang suture,as well as sedimentary provenance of nonmarine strata.A reverse fault placing melange rock on top of nonmarine strata along the eastern flank of the Ganzi-Litang suture indicates a contractional deformational regime during *** clast counts indicate a local sediment source of recycled Ganzi-Litang suture and Yidun terrane *** zircons indicate a localized provenance consisting of recycled material from Triassic Yidun Arc plutons and Triassic Yidun Group turbidite rock.A weighted mean average of Cenozoic zircon grains(n=10) establishes a maximum depositional age of41.5 ± 1.2 Ma for nonmarine strata in the Ganzi-Litang *** interpret the maximum depositional age of the nonmarine strata to represent the upper-limit for structural reactivation along the Ganzi-Litang suture while undeformed Neogene strata in the suture zone represent the lower-limit;thereby bracketing structural reactivation from ca.42-25 *** results provide enhanced spatial-temporal resolution for Cenozoic deformation in the eastern Tibetan Plateau.

关键词： nonmarine strata Yidun terrane Tibetan plateau Zircon Suture zone Reactivation

The Cretaceous System in China

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Acta Geologica Sinica(English Edition) 2007年第6期81卷 957-983页

作者： WAN Xiaoqiao CHEN Peiji WEI Mingjian Capital Normal University 105 Xishanhuan Beilu Bering 100037 China University of Geosciences 29 Xueyuan Road Beijing 100083 Nanjing Institute of Geology and Palaeontology Chinese Aca-demy of Sciences Nanjing Jiangsu 210008

This paper provides an outline of Cretaceous stratigraphy and paleogeography in China, which is based on rich data obtained from recent researches. Cretaceous deposits are widespread in China. Most strata are of nonmarine origin and marine sediments occur only in Tibet, western Tarim Basin of Xinjiang, Taiwan and limited localities of eastern Heilongjiang. AH deposits are rich in fossils and well-constrained biostratigraphically. The stratigraphic successions of different regions are illustrated, and general stratigraphic division and correlation have been introduced. The marine deposits are described in the Tibetan Tethys, Kashi-Hotan Region of Xinjiang, eastern Heilongjiang, western Yunnan and Taiwan; the nonmarine deposits are outlined from northeast China, southeast China, southern interior China, southwest China, the Shaanxi-Gansu-Ningxia region, and northwestern China intermontane basins. The sedimentary facies and paleogeography are diversified. In Tibet the basin evolution is largely related to the subduction and collision of the Indian Plate against the Eurasian Continent, and shows a tectonic evolution in the Cretaceous. Foraminifera are a dominant biota in the Tibet Tethys. nonmarine sediments include variegated and red beds, coal- or salt-bearing horizons, and volcanic rocks. These deposits contain diverse and abundant continental faunas and floras, as well as important coal and oil resources. The Cretaceous stratigraphy and paleogeography in China have presented a foundation for geological studies.

关键词： China Cretaceous stratigraphy paleogeography marine nonmarine

Sedimentary Basin Analysis and Petroleum Potential of the Cretaceous Yuchon Group in Haenam Depression, SW Korea

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Global Geology 2000年第2期5卷 188-196页

作者： Son Jin - Dam (Korea Institute of Geology, Mining and Materials, Taejon 305 - 350, Korea ) Korea Institute of Geology Mining and Materials Taejon 305 - 350 Korea

The Yuchon Group in the Late Cretaceous of Haenam and Mokpo area on the southwest coast of Korea peninsula can be divided into two Formations: (1) the intermediate volcanic Formation (Hwawon Formation), about 500m thick, (2 ) the acidic volcanic Formation (Hwangsan Formation), about 400m thick in ascending order The former comprises intermediate volcaniclastics interlayered with volcanic rocks, and red mudrock and tuffaceous sandstone indicating fluvial deposits. The latter is subdivided into the upper part (Hwangsan Tuff Member) consisting of subaerial pyroclastics and intercalated rhyolites, and the lower part (Byeongonri Member) including subaqueous volcaniclastics, lake deltaic sandstone and gravelstone, lacustrine black shale and limestone and chert, and lake turbidite sandstone. The Late Cretaceous basin including Haenam subbasin in southwest Korea was largely formed of extensional nonmarine depressions (volcano - tectonic) bounded by NE - SW sinistral fault system. The thermal maturation based on geochemical and mineralogical studies for the black shales and tuffaceous sandstones reached the late stage of oil generation zone or gas generation stage. It seems that black shales and limestones are fairly good as source rock. The porosity of potential reservoir sandstone and tuff ranges from 5 % to 11 %, but their permeability except the fractured rocks is very low (< 1md) because of fine pore throats reduced by diagenetic cementation of tuffaceous sandstones. Numerous potential traps might have been formed by the later folding and faulting along with lateral factes change and abundant mudrocks and volcaniclastics should make excellent seals.

关键词： Late Cretaceous nonmarine basin Basin evolution and volcanic activity Volcanism and petroleum geology