关岭及相关生物群沉积与生态环境的探讨  

SEDIMENTARY AND PALAEOECOLOGICAL ENVIRONMENTS OF THE GUANLING AND RELATED BIOTAS

作　　者：汪啸风[1] 陈孝红[1] 程龙[1] 王传尚[1] Bachmann G H Sander M Hagdorn H 

机构地区：[1]宜昌地质矿产研究所 [2]Insitute of Geology,Martin Luther University,Halle-Wittenberg [3]Institute of Paleontology,Bonn University,Nussallee 8,Bonn [4]Muschelkalkmuseum,D-74653 Ingelfingen

出　　处：《古生物学报》2009年第3期509-526,共18页Acta Palaeontologica Sinica

基　　金：中国地质调查局关岭生物群及环境演化工作项目(1212010611603)资助

摘　　要：根据近年来对黔东南至滇东关岭、兴义、贞丰和罗平等地中-晚三叠世含海生爬行动物骨架和(或)深水海百合黑色岩系(通常所称黑色页岩)化石库的研究,现将该区岩石地层单位划分,以及这些黑色岩系化石库生物组合特征、时代、分布、沉积和古地理环境概括如下:1)在关岭—兴义地区中-晚三叠世(安尼期、拉丁期和早卡尼期)地层中,至少夹有3层、甚至4层含海生爬行动物的黑色岩系化石库(或黑色"页岩"化石库),自下而上产盘县生物群、兴义生物群和关岭生物群。云南罗平地区中三叠统关岭组中新发现的"罗平生物群"与盘县生物群层位大致相当。贞丰龙场赖石科组上部新挖掘出的30m厚产创口海百合、双壳类及菊石的黑色岩系,应该是研究地区最高层位的海相三叠纪黑色岩系,时代似属晚三叠世早卡尼期晚期;2)推测这些含海生爬行动物骨架的黑色岩系化石库是在印支造山运动影响下,伴随南盘江前陆盆地隆升和闭合,在扬子克拉通台地边缘所形成的一个或几个边缘凹陷、或边缘盆地之中形成的,这些凹陷或盆地形成之初,表层水充氧,且具有很好的食物链结构,有利于各类海生生物生活;后来的海平面上升至最大海泛期,以及由此引起缺氧和含硫化氢水位的上升,导致这些凹陷逐渐变成安静、滞流的死亡之海和黑色岩系化石库;3)关岭生物群产于晚三叠世卡尼期早期小凹组下段上部黑色岩系之中,是一个典型的在滞流、缺氧且海底没有食腐动物边缘局限盆地中所形成的黑色页岩化石库,以产大量海生爬行动物和深水假浮游海百合为特征,此外还有个别的两栖类和原始龟类发现;4)产于竹杆坡组近底部黑色岩系中的兴义生物群,以产大量肿肋龙类为特点,尤以个体较小的贵州龙最为常见,共生的还有多种鱼类化石,在生物组合和产出层位上,可与阿尔卑斯南部Meride灰岩�Based on recent studies of the Middle-Upper Triassic black rock series（so called black ＂shale＂） fossil Lagerstttes,bearing marine reptile skeletons in association sometimes with pelagic crinoids,etc.from Guanling,Xingyi,Zhenfeng and Luoping areas in SW Guizhou to E Yunnan,China,we hereby present our analysis of the assemblage features,time-spatial distribution,sedimentary,palaeoecological and taphonomic environments as well as the subdivision and correlation of the lithostratigraphic units concerned,as summarized in the following：1） A total of three or four black rock series fossil Lagerstttes with laminated structure and ash interbeds are present in the Middle and Upper Triassic（Anisian,Ladinian and early Carnian） strata.They separately host the Panxian biota,the Xingyi biota and the Guanling biota.The Middle Triassic（Anisian） Luoping biota found in the Guanling Formation of Luoping area seems to be equivalent to the Panxian biota in horizon.The black rock series of about 30m thick with pelagic pseudoplanktonic crinoids（Traumatocrinus）,bivalves（Daonella） and ammonoids,excavated recently from the uppermost Laishike Formation at the Longchang section near Zhenfeng,is considered as the youngest marine Triassic deposits in the study area,probably belonging to the late early Carnian age;2） Those black rock series fossil Lagerstttes,with well-preserved marine reptile skeletons,are suggested to be in one or several marginal depressions（or called back bulge） or basins,caused by the folding and uplift of the Nanpanjiang foreland basin along with the Indo-China orogenesis,in the margin of the Yangtze craton platform.These depressions had living condition suitable for marine organisms with generally aerated surface waters and good food web in their initial stage.Followed by the occurrence of sea-level rise to the maximum flooding interval,and the resulting going up of the oxygen-deficient and H_2S-enriched water zone,these depressions gradually become quiet and stagnant sea of dea

关 键 词：关岭生物群 兴义生物群 盘县生物群 黑色岩系 海生爬行动物 中-上三叠统 边缘盆地 前陆盆地 

分 类 号：Q911[天文地球—古生物学与地层学]