摘要
华南地区晚二叠世末碳酸盐台地上广泛发育一套钙质微生物岩,这些钙质微生物岩以发育“花斑状”构造为特征,部分微生物岩伴生有叠层石层、鲕粒灰岩层。通过仔细的野外和室内工作,初步揭示微生物岩产出的古地理环境、时代、微生物岩内化石的组成、岩石特征以及岩石地球化学特征。
通过野外观察,微生物岩出露的古地理位置大致可以分为三类:(1)南盘江盆地内孤立碳酸盐台地上;(2)上扬子地区台内生物礁顶上;(3)中下扬子碳酸盐台地边缘生物礁顶上。微生物岩和上下地层之间为一种整合的接触关系。厚度从几米到十几米不等,并向台地周围深水区逐渐尖灭。
通过对微生物岩中已发现的牙形石化石的综合分析,发现所研究的6条剖面中均产有牙形石化石H.parvus。据现有的发现,H.parvus均出现在微生物岩的内部,距微生物岩底部(绝灭界线)有一定的距离。通过与浙江煤山标准剖面的对比,将微生物岩的时代确定为晚二叠世末到早三叠世早期。
微生物岩中的化石主要以钙质微生物为主,同时伴生有小型的腹足、双壳、有孔虫和介形虫,在一些微生物岩中还发现有分类不明的棒状化石。微生物岩所代表的这种特殊的古代生态系可称之为菌藻生态系。微生物岩中钙质微生物化石主要以两种形态出现,即“束囊状”和球状。“束囊状”化石经初步鉴定为肾形藻(Renalcis)或Epiphyton。微生物岩中菌藻类化石的发现为了解大绝灭后礁顶上残存下来的古生物群落的组成及当时的古海洋环境提供了重要的化石材料。
从岩石特征上看,微生物岩主要以发育“花斑状”构造为特征,但不同地区表现形式有所不同。在南盘江盆地南边的广西地区,微生物岩以斑状和丘状构造为主要特征;在北边的贵州边阳地区,则表现为纹带构造,同时可见大型的藻叠层;而川东地区钙质微生物岩以发育穹隆状构造、纹带状构造及指状构造为主要特征;鄂东南地区表现为纹带状构造和丘状构造,局部出现柱状叠层构造。引起微生物岩的这种岩性差异的原因可能是其沉积水深的不同,同属于浅海相沉积的微生物岩,水深细微的不同,就可能造成不同的岩石特征。但微生物岩在岩石结构上基本一致,即由微晶基质和中、粗晶方解石指状体或斑点所组成。
通过对微生物岩的岩石地球化学分析,认为微生物岩形成于一个盐度相对较高的水化学环境中。另外,地球化学分析显示微生物岩受后期成岩变化的影响较小,基本保持了成岩时的特征。微生物岩中常量元素Mg的变化和微量元素Sr的高含量可以用来解释当时古海洋的高盐度。稀土元素分配曲线结果显示,在作登微生物岩上的泥岩层的沉积物来源应该与台地沉积物无关,可能是由于海水翻转将深海沉积物涌起,而在台地上形成。稀土元素Ce在“花斑状”微生物岩中的负异常揭示了这类微生物岩形成于一个相对氧化的水环境中,但Ce在其他灰岩中的分布特征仍显示了火绝灭后海洋为一种普遍的缺氧水体。
碳氧同位素分析显示,碳稳定同位素的负偏主要出现在微生物岩与晚二叠世生物碎屑灰
The microbialites occur widely above the mass extinction line in the Late Permian carbonate platform in South China. The microbialites are characterized by the peculiar structure of "graniphyic fabric", as well as stromatolite and oolites at some locations. After carefully observe and study, we make clear the paleogeography position and age of the microbialites. The fossil composition, lithology and geochemistry characters have been studied too.
The microbialites' paleogeography position can be divided into three types: (1) on the top of the isolated carbonate platform within the Nanpanjiang Basin; (2) on the top of reefs which were developed within the Upper Yangtze platform; (3) on the top of reefs which were built up along the margin of Middle-Lower Yangtze platform. The microbialites had a conformity relationship with the overlying and underlying strata. The thickness of the microbialites was from several meters to tens meters, and gradually disappeared from shallow water to deep water.
According to the study of conodonts, H.parvus fossils have been found in the microbialites from six sections. All the conodont fossils found so far are produced within the microbialites and have a distance to the bottom of the microbialites. By correlation with the GSSP at Meishan, it is proposed that the microlialites spanned the latest Permian and Earliest Triassic.
Calcified microbe are the main fossils discovered in the microbialites, and some micro-gasteropods, bivalves, foraminifer, ostracods, micro-problematical fossils can also be found. This special ecological system represented by the microbialites may be called bacterium-alga system. Globular cynobacteria and chambered fossils are the main types of calcified microbe. The chambered fossils had been identified as Renalcis or Epiphyton. The calcified microbe found in the microlialites provides important material for study of ancient biotic community on the top of the reefs and the conditions of the ancient marine environment after mass extinction.
Generally, the microbialites displays the structure of "graniphyic fabric". However, there are some other different lithological characteristics in different places. The microbialites in the South of Nanpanjiang Basin have characteristics of spot and mound structure. The microbialites in the north of the basin have veins or big stromatolite. In East Sichuan, the microbialites characteristics were arched, veins and digitate structure. Microbialites in South-east Hubei have veins, mound structure and stromatolites. This different maybe explain the vary depth of the water. However, the
引文
曾瑞骥.新元古代奇异叠层石和凝块石中可疑的动物活动证据.古生物学报,1999.38(3):291-304.
曾瑞骥,袁训来.中国叠层石研究的历史和现状.微体古生物学报,2003.20(1):5-14.
曹瑞骥,袁训来,肖书海.论锥叠层石群(Conophyton)的形态发生——对苏北新元古代九顶山组一个似锥叠层石的剖析.古生物学报,2001.40(3):318-329.
陈晋镳.论叠层石的地层意义,甘肃地质学报,1994.第3卷第一期,1-10.
戴永定,陈孟莪,王尧.微生物岩研究的发展与腱望.地球科学进展,1996.11(2):209-215.
方宗杰,从华南二叠纪-三叠纪礁生态系的演变探讨与灭绝-残存-复苏相关的几个问题.见:戎嘉余.方宗杰,生物大灭绝与复苏-来自华南古生代和三叠纪的证据.合肥:中国科学技术大学出版社,2004.475-542.
冯洪真,E.Wallis,刘家润等.川西南阿什及尔期地层中的Ce异常及其古海洋学意义.火山地质与矿产.2001.22(2);126-134.
胡明毅.塔北柯坪奥陶系碳酸盐岩地球化学特征及环境意义.石油与天然气地质,1994.15(2):158-163.
胡明毅.中扬子台地北缘上震旦统碳酸盐岩中锶的分布特征及环境意义.岩石矿物学杂志,1999.18(3):243-246.
黄汲清.陈炳蔚.中国及邻区特提斯还的演化.北京:地质出版社,1987.1-109.
赖旭龙,张克信.二叠-三叠纪之交牙形石生态新模型.地球科学,1999.24(1):33-38.
李文恒.我国东南地区上二叠统的几个问题.地层学杂志,1979.3(2):113-122.
廖卓庭.广西来宾合山晚二叠世硅化腕足类及其古生态特征[A].二叠系与三叠系界限(一)IM].南京:南京大学出版社.1987.81-130.
芮琳,江纳言,陈楚震.中国南部二叠纪末和三叠纪初的沉积分区及其相型.中国科学(B辑),1983.(6):560-565.
芮琳,江纳言.苏浙皖地区二叠纪末和三叠纪初的岩相和古生物相.古生物学报,1984.23(5):286-296.
戎昆方,李景阳,安裕国.初论生物成因的洞穴叠层石的形成条件.中国岩溶,1998.17(3):285-290.
王成源(主编).下扬子地区牙形刺——生物地层与有机变质成熟度的指标.北京:科学出版社.1993.1-326.
王福星,曹建华,江利登等.岩溶洞穴叠层石.古生物学报,1994.33(2):172-179.
王立亭,陆彦邦,赵时久等.中国南方二叠纪岩相古地理与成矿作用.北京:地质出版社,1994.1-137.
王永标,童金南,王家生等.华南二叠纪末大绝灭后的钙质微生物岩及古环境意义,科学通报,2005.50(6):552-558.
王自强,全秋琦.宜昌峡东地区的现代叠层石,地质科学,1982.04期.
杨浩,张素新,江海水,王永标,湖北崇阳二叠纪-三叠纪之交钙质微生物岩的时代及基本特征。地球科学——中国地质大学学报,2006,31(2):165-170.
杨守仁,郝维城,王新平.广西二叠 三叠系界线层牙形石演化、分带及二叠 三叠系界线.见:八尾昭等著,中国古特提斯生物及地质变迁.北京:北京大学出版社.1999a.81-85.
杨守仁,王新平,郝维城.广西西部早、中三叠世牙形石序列.北京大学学报(自然科学版),1986(4):90-106.
杨遵仪,吴顺宝,殷鸿福等.华南二叠-三叠纪过渡时期地质事件[M].北京:地质出版社.1991.
殷鸿福,黄恩骥,张克信,等.华南二叠-三叠纪之交的火山活动及其对生物绝灭的影响.地质学报.1989.63(2):169~181
朱士兴.中国叠层石.天津:天津大学出版社.1993.191-196.
张克信.浙江长兴地区二叠纪与三叠纪之交牙形石动物群及地层意义.地球科学——武汉地质学院学报,1987.12(2):193-200
周祖仁.二叠纪菊石的两种形态类型.中国科学(B辑),1985.(7):648-657.
周祖仁,朱德寿,李富玉等.华南二叠纪茅口的边缘海域及菊石群.古生物学报,1995.34(5):525-548.
Baud, A., Holser, W. T., Magaritz, M., Permian/Triassic of the Tethys:Carbon isotope studies. Grol. Rundschun, 1989. 78:1-25.
Becker, L., Poreda, R.J., Hunt, a.G., et al., Impact Event at the Permian-Triassic boundary: Evidence from extraterrestrial noble gases in fullerenes.Science 2001. 291, 1530-1533.
Bowring, S. A., Erwin, D.H., Jin, Y.G., et al., U/Pb Zircon Geochronology and Tempo of the End-Permian Mass Extinction. Science 1998. 280, 1039-1045.
Buren. R. V., and Moote L.S., Microbialites organosedimentary deposits of bethic microbial comminunities. Palaios. 1987. V. 2, P. 241-254
Bush, I. P., Upper Permian(?) and Lower Triassic metasedimentary rocks, northeastern Baja California Mexico. In: Frizzell V A Jr, ed. Geology of the Baja California Peninsula. Society of Economic Paleontologists and Mineralogists. Pacific Section, 1984. 39:31~36
Campbell, I. H., Czamanske, G.K., Fedorenko, V.A., et al., Synchronism of the Siberian Traps and the Permian-Triassic boundary. Science 1992. 258, 1760-1763.
Crasquin, S. S., Kershaw-Stephen., Ostracod fauna from the Permian-Triassic boundary interval of south China (Huaying Mountains, eastern Sichuan Province); palaeoenvironnmental significance. Palaeogeography, Palaeoclimatology, Palaeoecology. 2005. 217; 1-2, Pages 131-141.
De Baar. H. J. W., Bacon, M. P., Brewer, P. G, et al., Rare earth elements in the Pacific and Atlantic oceans[J].Ceochim.Cosmochim. Acta, 1985. 49:1943-1959.
de Wit, M. J., Gosh, J.G., de Villiers, S., et al., Multiple organic carbon isotope reversals across the Permian-Triassic boundary of terrestrial Gondwana sequences: Clues to extinction patterns and delayed ecosystem response.J. Geol. 2002.110, 227-240.
Duane, M. J,, Al-Zamel, A. Z., Syngenetic textural evolution of modern sabkha stromatolites (Kuwait). Sedimentary Geology. 1999. 127:237-245
Erwin, D. H., The Great Paleozoic Crisis: Life and Death in the Permian. Columbia University Press, New York. 1993.
Erwin, D. H., The Permo-Triassic Extinction. Nature.1994. 367, 231-236.
Ezaki, J., Liu, J., Adachi, N., Earliest Triassic microbialite micro- to megastructures in the Hnaying Mountains area of Sichuan Province, south China: implications for the nature of oceanic conditions after the end-Permian extinction. Palaios 2003. 18, 388-402.
Faure, K., de Wit, M.J., Willis, J.P., Late Permian global coal hiatus linked to ~(13)C-depicted CO_2 £ux into the atmosphere during the final consolidation of Pangea.Geology 1995.23, 507-510
Corsetti, F. A., Baud, Av., Marenco, P. J., et al., Summary of Early Triassic carbon isotope records. GeneralPaleontology(Paleoecology). 2005. (4)473-486.
Grotzinger, J., Adams, E. W., Schroeder, S., Microbial-metazoan reefs of the terminal Proterozoic Nama Group (c. 550-543 Ma), Namibia. Geological Magazine. 2005. 142: 5, Pages 499-517.
Groves, J. R., Altiner. D., Boyce, M. D., Craig, B. J., "Disaster oolites" in the Permian-Triassic boundary interval, Tauride Mountains (Turkey). Abstracts with Programs-Geological Society of America. 2003. 35; 2, Pages 48.
Groves, J. R. and Calner, M., Lower Triassic oolites in Tethys; a sedimentologic response to the end-Permian mass extinction. Abstracts with Programs-Geological Society of America. 2004. 36; 5, Pages 336.
Hofmaun, H. J., Stratiform Precambrian stromatolites, Belcher Islands, Canada: Relations between silicified microfossils and microstructure. Am J Sci, 1975. 275: 1121~1132
Holser, W. T., Magaritz, M., Events near the Permian-Triassic boundary.Mod. Geol. 1987. 11, 155-180.
Holser, W.T., Scho.. nlaub, H.P., Attrep, M., Jr., et al., A unique geochemical record at the Permian/Triassic boundary.Nature 1989. 337. 39-44.
Horodyski, R. J., Vonder Haar. S. P., Recent calcareous stromatolites from Laguna Mormona (Baja California) Mexico. Journal of Sedimentary Petrology. 1975. 45(4): 894~906
Isozaki, Y., Permo-Triassic boundary superanoxia and stratified superocean: records from lost deep sea.Science 1997. 276, 235-238.
Jin, Y. G., Pre-Lopingian Benthos Crisis. Computes Rendus Ⅻ ICC-P, 1993.2: 269-278.
Jin. Y.G.. Wang, Y., Wang, W., et al., Pattern of marine mass extinction near the Permian-Triassic boundary in south China.Science 2000. 289,432-436.
Jin, Y., Wardlaw, B.R., Glenister, B.F., et al., Permian chronostratigraphic subdivisions.Episodes 1997. 20, 6-10.
Kaiho, K., Kajiwara, Y., Nakano, T., et al., End-Permian catastrophe by a bolide impact: Evidence of a gigantic release of sulfur from the mantle.Geology 2001. 29, 815-818.
Kajiwara, Y., Yamakita, S., Ishida, K., et al., Development of a largely anoxic stratified ocean and its temporary massive mixing at the Permian/Triassic boundary supposed by the sulfur isotopic reeord.Palaeogeo gr. Palaeoclimatol.Palaeoecol. 1994.111, 367-379.
Kershaw, S., Guo, L., Swift A., et al.,. ?Microbialite carbunate crust at the Permian-Triassic interval in central China:structure, age and distribution. Facies 2002. 47, 83-90.
Kershaw, S., Zhang, T.S., Lan, GZ., A? microbialite carbonate crust at the Permian-Triassic boundary in South China, and its palaeoenvironmentai significance. Palaeogeography, Palaeoclimatology, Palaeoecology 1999.146, 1-18.
King, G. M., Terrestrial tetrapods and the end Permian event: A comparison of analyses.Hist. Biol. 1991.5, 239-255.
Knoll, A. H., Bambach, R. K., Canfield, D. E., et al., Comparative Earth history and the Late Permian mass extinction. Science1996. 273, 452-457.
Kozur, H. W.,. Pelagic uppermost Permian and Permian.-Triassic boundary conodonts of Iran. Part 1: Taxonomy. Hallesches Jahrbuch Geowissenschaften, Reihe B, Beiheft, 2004. 18: 39-68.
Krull, E. S., Lehrmann, D. J., Druke, D., et al., Stable carbon isotope stratigraphy across the Permian-Triassic boundary in shallow marine carbonate platforms, Nanpanjiang Basin, South China. Palaeogeography, Palaeoclimatology, Palaeoccology. 2004. 204; 3-4, Pages 297-315.
Krull, E. S.. Retallack, G.J., ~(13)C depth profiles across the Permian-Triassic boundary: evidence for methane release. Boulder GeoI.Soc.Am.Bull. 2000. 112, 1459-1472.
Krull, E. S., Retallack, G.J., Campbell H.J., et al., ~(13)C_(org) chemostratigraphy of the Permian-Triassic boundary in the Maitai Group, New Zealand: evidence for high latitudinal methane release.N. Z.J.Geol.Geophys. 2000. 43, 21-32.
Krystyn, L., Richoz, S., Baud, A., et al., A unique Permian-Triassic boundary section from the Neotethyan Hawasina Basin, Central Oman Mountains.Palaeogeogr. Palaeoclima tol. Palaeoecol. 2003. 191, 329-344.
Lehrmann, D.J., Early Triassic calcimicrobial mounds and biostromes of the Nanpanjiang basin, South China. Geology. 1999. 27, 359-362.
Lehrmann, D.J., Payne, J.L., Felix. S.V., et al., Permian-Triassic boundary sections from shallow-marine carbonate platforms of the Nanpanjiang Basin,South China: implications for oceanic conditions associated with the end-Permian extinction and its aftermath. Palaios. 2003. 18.138-152.
Lehrmann, D.J.. Wei. J.Y., Enos, P., Controls on facies architecture of a large Triassic carbonate platform: the Great Bank of Guizhou, Nanpanjiang Basin, South China. Journal of Sedimentary Research. 1998. 68. 311-326.
Lehrmann, D.J.. Yang, W.. Wei, J.Y., et al., Lower Triassic peritidal cyclic limestone: an example of anachronistic carbonate facies from the Great Bank of Guizhou, Nanpanjiang Basin. Guizbou province. South China. Palaeogeography, Palaeoclimatology. Palaeoecology 2001. 173, 103-123.
Magaritz, M., Krishnamurty, R.V., Holser, W.T., Parallel trends in organic and inorganic carbon isotopes across the Permian/Triassic boundary.Am.J.sci. 1992. 292, 727-739.
Maxwell, W. D., Permian and Early Triassic extinction of non-marine tetrapods.Palaeontology 1992. 35, 571-584.
Miller, P., Dulski, P., Ban, M., Rare earth elements adsorption in a seawater profile above the east Pacific rise [J]. Chem. Erde, 1994. 54:129-149.
Morante, R., Permian and Early Triassic isotopic records of carbon and strontium in Australia and a scenario of events about the Permian^Triassic boundary.Hist.Biol. 1996.11,289-310.
Mundil, R., Metcalfe, I., Ludwig, K.R., et al., Timing of the Permian-Triassic biotic crisis: implications from new zircon U/Pb age data (and their limitations).Earth Planet.Sci. Lett. 2001. 187, 131-145.
Newell, N. D., Is there a precies Permian/Triassic boundary?. Permonphile Calgary, 1994.24:46-48.
Nicoll, R. S., Metcalfe, I., Wang, C. Y., New species of the conodont genus Hindeodus and the conodont biostratigraphy of the Permian-Triassic boundary interval. Journal of Asian Earth Sciences. 2002. 20(6): 609-631.
Payne, J.L., Lehrmann D. J., Wei, J. Y., et al., Large perturbations of the carbon cycle during recovery from the end-Permian extinction. Science. 2004. 305; 5683, Pages 506-509.
Peryt, T. M., Significance of stromatolites for the environmental interpretation of the Bundsandstein (Lower Triassic) rocks. Geologische Rundschau, 1975. 64: 143~158
Pratt, B. R., Epiphyton and Renalcis-diagenetic microfossils from calcification of coccoid blue-green algae. Journal of Sedimentary Petrology, 1984. 54(3): 948~971
Rampino, M.R., Prokoph, A., Adler, A., Tempo of the end-Permian event: High-resolution cyclostratigraphy at the Permian-Triassic boundary.Geology 2000. 28, 643-646.
Raup, D. M., Size of the Permo-Triassic bottleneck and its evolutionary implications.Science 1979.206, 217-218,
Raup, D. M., Sepkoski J. J., Mass exctinctions in the marine fossil record. Science, 1982. 215: 1501-1503
Reid, R. P., Macintyre, I. G., Microboring versus recystallization: further insight into the micritization process. J. Sediment. Res, 2000b. 70:24-28.
Renne, P. R., Zichao, Z., Richards, M.A., et al., Synchrony and causal relations between Permian-Triassic boundary crisis and Siberian flood volcanism. Science 1995. 269, 1413-1416.
Retallack, G. J., Permian-Triassic life crisis on Land. Science 1995. 267, 77-80.
Retallack. G. J., Seyedolali, A., Krull, E.S., et al., Search for evidence of impact at the Permian-Triassic boundary in Antarctica and Australia.Geology 1998. 26, 979-982.
Riding, R., Evolution of algal and cyanobacterial calcification. In: Bengtson S, ed. Early life on Earth. Columbia University Press, New York, Nobel Symposium, 1994. 84: 426-438.
Riding, R., Classification of microbial carbonates, Benthic microbes and reefs, discussion Sessions, 6th Inter. Coral reef symposium, abstracts, 1988.
Riding. R., Brasier. M., Earliest calcareous foraminifera. Nature. 1975, 257: 208~210
Rostovtsev, K. O., Azaryan N R. The Permian-Triassic boundary in Transcaucasia. In: Logan D H. Hills L V. eds. The Permian and Triassic Systems and Their Mutual Boundary. Canadian Society of Petroleum Geologists Memoir, 1973. 2: 89~99
Sano, H., Nakashima K. Lowermost Triassic (Griesbachian) microbial bindstone-cementstone facies southwest Japan. Facies, 1997. 36: 1~24
Sarkar. A.. Yoshioka. H., Ebihara. M., et al.. Geochemical and organic carbon isotope studies across the continental Perrno-Triassic boundary of Raniganj Basin, eastern India.Palaeogeogr. Palaeoclimatol. Palaeoecol. 2003.191, 1-14.
Schubert, J. K., Bottjer D J. Early Triassic stromatolites as post-mass extinction disaster forms. Geology, 1992. 20: 883~886
Sepkoski, J.J., Periodicity in marine extinction events. In: Elliott D K(ad.). Dynamics of extinction. New York, Wiley. 1986.3-36.
Shapiro, R. S., Diversity and abundance patterns of early Paleozoic microbialites. Abstracts with Programs Geological Society of America. 1999. 31; 7, Pages 335.
Shen J. W., Xu, H. L., Microbial carbonates as contributors to Upper Permian (Guadalupian-Lopingian) biostromes and reefs in carbonate platform margin setting, Ziyun County, south China. Palaeogeography, Palaeoclimatology, Palaeoecology. 2005.218; 3-4, Pages 217-238.
Stanley, S. M., Extinction. Freeman, New York. 1987.242 p.
Stanley, S. M., and Yang, X. N., A double mass extinction at the end of the Paleozoic Era.Science, 1994. 266:1340—1344.
Stemmerik, L., Bendix-Almgreen, S.E., Piasecki, S., The Permian-Triassic boundary in central East Greenland: past and present views.Bull. Geol.Soc.Denmark 2001.48, 159-167.
Tarza, H., The Permian and the Lower Triassic systems in Abadeh region, central Iran. Kyoto University, Geology and Mineralogy Series. Faculty of Science Memoirs, 1981. 47: 66~1339
Twitchett, R. J., Looy, C.V., Morante, R., et al., Rapid and synchronous collapse of marine and terrestrial ecosystems during the end-Permian biotic crisis.Geology 2001.29, 351-354.
Wang, K., Geldsetzer, H.H.J., Krouse, H.R., Permian-Triassic extinction: Organic δ~(13)C evidence from British Columbia, Canada.Geology 1994. 22. 580-584.
Wignall, P.B., Hallam, A.. Xulong, L., Fengqing, Y., Palaeoenvironmental changes across the Permian/Triassic boundary at Shangsi (N.Sichuan, China). Hist.Biol. 1995.10, 175-189.
Wignall, P. B., Hallam, A., Anoxia as a cause for the Permianfrriassic mass extinction: Facies evidence from northernItaly and the western United States.Palaeogeogr. Palaeoclimatol. Palaeoecol. 1992. 93, 21-46.
Wignall, P. B., Hallam, A., Griesbachian(Earliest Triassic) palaeoenviromental changes in the Salt Range, Pakistan and Southeast China and their bearing on the Permo-Triassic mass extinction. Palaeogeography, Palaeoclimatology, Palaeoecology. 1993. 102:215-237.
Wignall, P.B., Morante, R., Newton, R., The Permo-Triassic transition in Spitzbergen: δ~(13)C_(org) chemostratigraphy,Fe and S geochemistry, facies, fauna, and trace fossils.Geol.Mag 1998.135, 47-62.
Wignall, P. B., Twichett, R.J., Oceanic anoxia and the End Permian mass extinction.Science 1996.272, 1155-1158.
Wignall, P. B., Twitchett. R.J, Extent, duration, and nature of the Permian-Triassic superanoxia event.Boulder Geol.soc. Am.Spec.Pap.3 2002.56, 395-413.
Wray, J. L.. Calcareous Algae. Amsterdam, Oxford. New York: Elsevier, 1977. 185
Wright. J., Schrader, H., Holser. W., Paleoredox variations in ancient oceans recorded by rare earth elements in fossil apatite [J].Geochim. Cosmochim. Acta, 1987. 51: 631-644.
Wright. J., Seymour, R. S., Shaw, H., REE and Nd isotopes in conodont apatite: Variations with geological age and depositional environment [J]. Geol. Soc. Amer. Spec.Pap., 1984.196:325-340.
Yang, W., Lehrmann, D.J., Milankovitch climatic signals in Lower Triassic (Olenekian) peritidal carbonate successions, Nanpanjiang Basin, South China. Palacogeography, Palaeoclimatology, Palaeoecology. 2003.201; 3-4, Pages 283-306.
Yin, H. F., Glenister, B. E, Kotlyar, G. V., et al., Recommendation of the meishan section as global stratotype section and point for basal boundary of Triassic System. Newsletter Stratigraphy, 1996.34(2):81-108.
Yin, H. F., Wu, S. B., Din, M. H., et al., The Meishan section-candidate of the Global Stratotype Section and Point of the Permian-Triassic boundary [J]. Albertiana, 1994, 14: 15-30.
Yin, H. F., Yang, F. Q., Zhang, K. X., et al., A proposal to the biostratigraphic criterion of the Permian-Triassic boundary. Memerie Delia Societa Geological Italiana, 1986.36: 329-334.
Yin, H. F., Zhang, K. X., Tong, J. N., et al., The Global Stratotype Section and Point (GSSP) of the Permian-Triassic Boundary. Episodes, 2001. 24: 102-114.
Zhang, Q., Xu, D., Inquiring into indicators and origin of catastrophic events at stratigraphic boundaries.J. Southeast Asian Earth Sci. 1996.13, 373-378.