【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灰岩所夹黑色含沥青页岩化石库对比,时代似应归属拉丁期早或中期;大量米虾在竹杆坡组近底部含贵州龙层的发现,推测兴义生物群可能形成于台地边缘早期并不缺氧,且具有理想食物链结构的浅水、超盐的凹陷或盆地之中。由于存在浮游生物—虾—贵州龙—欧龙—虾—浮游生物所组成的生态组合和食物链结构,从而为解释以肿肋龙类为代表的兴义生物群的繁衍和多生提供了依据;接踵而来的沉积速率下降和缺氧水位的上升,以及间歇性火山作用,导致该特有生态体系的崩溃和化石库的形成。根据对贞丰挽澜竹杆坡组底部首次发现的棘皮动物的化石库的研究,指出该化石库系由海星、细小蛇尾、底栖海百合茎、海胆和海参等5类棘皮动物化石和含贵州龙骨架碎片组成,其下为8m厚夹有薄层的骨层的凝缩层沉积,后者位于硬底之上。此种沉积和埋藏模式与德国上壳灰岩早拉丁期的棘皮动物化石库类似,是在近岸海水不太浅的内陆棚的环境下,由于风暴潮作用所形成的化石库,他们与在滞流、缺氧海底、通过化石聚集所形成的化石库是不同的;5)产盘县生物群的黑色岩系化石库主要见于盘县羊件和普安青山中三叠世(安尼期)关岭组中,与云南罗平地区的"罗平生物群"在层位及生物组合上大致相当,均以含大量混鱼龙、幻龙和欧龙,以及鱼类为特点,共生的还有大量节肢动物。所不同的是后者由于靠近滨岸,故而出现大量幼年期的鱼类以及虾类和鲎类化石,推测他们形成于靠近古陆或滨岸的台缘浅水表层充氧的正常、且有时超盐的凹陷之中,时代上早于阿尔卑斯南部安尼期/拉丁期比塞娄组;其集群死亡除因后期盆地滞流、缺氧外,可能还与风暴和火山作用有关。更多还原

【Abstract】 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 H₂S-enriched water zone,these depressions gradually become quiet and stagnant sea of death and black rock series fossil Lagerstttes;3) The Late Triassic（early Carnian） black rock series fossil Lagersttte,typically represented by the Guanling biota,occurring in the upper Lower Xiaowa Formation,is considered to be deposited under anoxic or dysoxic restricted basin without scavengers in the bottom.It is characterized by the presence of numerous marine reptile skeletons（ichthyosaurs,thalattosaurs,and a few placodonts） with a number of pelagic pseudoplanktonic colonies（Traumatocrinus）,rare fishes,except for one plagiosaurid and one original turtle found recently near the basin margin;4) The Xingyi black rock series fossil Lagersttte,located in the lowest Zhuganpo Formation,is characterized by the occurrence of thousands of skeletons of pachpleurosaurids,especially the Kweichousaurus reaching 15—20cm long,and lots of fishes.It appears similar to the black bituminous shale fossil Lagersttte（i.e.the Cave-inferiore and Cave-superiore shales intervals） hosting pachpleurosaurids in the Meride Limestone of Southern Alps and to be of the early or middle Ladinian age.The discovery of numerous small shrimps（Schimperella） at the base of the pachypleurosaur beds seems in favour of the hypothesis that the Xingyi biota would have been formed in a restricted shallow hypersaline basin with aerated surface waters and good food web,composed of planktons-shrimps（Schimperella）-Kweichousaurus-Lariosaurus-Schimperella-planktons.The new evidence may explain why pachypleurosaurs were so flourishing with so high breeding rate in the biota.Subsequent decrease in sedimentation rates and rise in oxygen-deficient water levels with intermittent volcanic activities would lead to the breakup of the specialized ecosystem and the formation of the fossil Lagersttte.An echinoderm fossil Lagersttte,composed of（Starfish）（Trichasteropsis）,small ophiuroids（? Aspiduriella）,benthonic crinoids—encrinid columnals,echinoids（Triadotiaris）,and sea cucumber（holothurians） fossils,with skeleton fragments of Kweichousaurus,are first found near the base of the Zhugangpo Formation at Wanlan of Zhenfeng.The underlying condensation beds with thin bonebed layers about 8m above the hard ground overlying the Yangliujing Formation.This sedimentary and taphonomic mode reminiscent of Muschelkalk bedding planes with thin bonebed layers might have resulted from storm activity（storm tide） near the inner shelf and different from the fossil Lagersttte mentioned above through the accumulation of fossils in the stagnant and oxygen-deficient bottom sediments over a prolonged time period;5)The black rock series,hosting the Panxian biota,are mainly present in the Middle Triassic（Anisian） Guanling Formation in Yangjian of Panxian and Qingshan of Pu’an.It is characterized by occurrence of numerous mixosaurs,nothosaurs,lariosaurs and fishes,such as Saurichthys,arthropods,etc.and earlier than the Besano Formation of Anisian/Ladinian Stages in the Southern Alps.The Luoping biota appears roughly equivalent to the Panxian biota in horizon and biological assemblage,but contains numerous juvenile fishes,shrimps and limulus due to closeness to the coast.It is suggested that the Panxian biota and "Luoping biota" would be formed in a restricted open marine,salinity normal,or sometimes hypersaline marginal depressions close to the coast with aerated surface waters.Their mass death might have resulted from the stagnant and anoxic events associated with the maximum transgression,subsequent sea level down,and reduced basin size.Besides,the mass death of a large number of juvenile fishes might be related to unexpected storm and volcanic event.更多还原