{"title":"阿根廷前科迪勒拉Cerro La Silla地区奥陶系上拉西拉组和圣胡安组(特雷马多世-大平纪下)牙形石生物相","authors":"M. Mango, undefined Guillermo L. Albanesi","doi":"10.5852/cr-palevol2021v20a35","DOIUrl":null,"url":null,"abstract":"Conodonts from the upper La Silla (9.6 m thick) and San Juan formations (264.7 m thick) at the Cerro La Silla section are analyzed for the identification of faunal dynamics, biofacies and sea-level changes. The conodont collection of 11 388 specimens was recovered after digestion of 41 samples of carbonate rocks, totalizing 88.155 kg. Conodont total abundance and generic diversity graphs, as well as cluster analysis, reveal seven biofacies. The Colaptoconus, Tropodus-Reutterodus, Oepikodus-Prioniodus, Juanognathus-Bergstroemognathus, Juanognathus-Oepikodus-Protopanderodus, Juanognathus-Protopanderodus, Juanognathus-Semiacontiodus biofacies are determined. These biofacies represent middle to outer carbonate ramp environments for the San Juan Formation. The associated analysis of biofacies and lithology allow for the recognition of two transgressive events in the San Juan Formation at the Cerro La Silla section, which could be related to transgressive systems tracts (TST) that occurred during the Early and Middle Ordovician (middle Tremadocian-early Dapingian).","PeriodicalId":51002,"journal":{"name":"Comptes Rendus Palevol","volume":"39 1","pages":""},"PeriodicalIF":1.2000,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":"{\"title\":\"Ordovician conodont biofacies of the upper La Silla and San Juan formations (middle Tremadocian-lower Dapingian) at Cerro La Silla, Argentine Precordillera\",\"authors\":\"M. Mango, undefined Guillermo L. Albanesi\",\"doi\":\"10.5852/cr-palevol2021v20a35\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Conodonts from the upper La Silla (9.6 m thick) and San Juan formations (264.7 m thick) at the Cerro La Silla section are analyzed for the identification of faunal dynamics, biofacies and sea-level changes. The conodont collection of 11 388 specimens was recovered after digestion of 41 samples of carbonate rocks, totalizing 88.155 kg. Conodont total abundance and generic diversity graphs, as well as cluster analysis, reveal seven biofacies. The Colaptoconus, Tropodus-Reutterodus, Oepikodus-Prioniodus, Juanognathus-Bergstroemognathus, Juanognathus-Oepikodus-Protopanderodus, Juanognathus-Protopanderodus, Juanognathus-Semiacontiodus biofacies are determined. These biofacies represent middle to outer carbonate ramp environments for the San Juan Formation. The associated analysis of biofacies and lithology allow for the recognition of two transgressive events in the San Juan Formation at the Cerro La Silla section, which could be related to transgressive systems tracts (TST) that occurred during the Early and Middle Ordovician (middle Tremadocian-early Dapingian).\",\"PeriodicalId\":51002,\"journal\":{\"name\":\"Comptes Rendus Palevol\",\"volume\":\"39 1\",\"pages\":\"\"},\"PeriodicalIF\":1.2000,\"publicationDate\":\"2021-08-27\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"3\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Comptes Rendus Palevol\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.5852/cr-palevol2021v20a35\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"PALEONTOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Comptes Rendus Palevol","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.5852/cr-palevol2021v20a35","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PALEONTOLOGY","Score":null,"Total":0}
引用次数: 3
摘要
分析了Cerro La Silla剖面上La Silla组(9.6 m厚)和San Juan组(264.7 m厚)的牙形刺,以确定动物动态、生物相和海平面变化。对碳酸盐岩样品41件进行消化后,回收牙形石标本11 388件,总重量为88.155 kg。牙形石总丰度和属多样性图以及聚类分析显示了7种生物相。确定了Colaptoconus、Tropodus-Reutterodus、Oepikodus-Prioniodus、Juanognathus-Bergstroemognathus、Juanognathus-Oepikodus-Protopanderodus、Juanognathus-Protopanderodus、Juanognathus-Semiacontiodus生物相。这些生物相代表了圣胡安组中至外碳酸盐岩斜坡环境。通过生物相和岩性分析,确定了Cerro La Silla剖面圣胡安组的两次海侵事件,可能与早、中奥陶世(特雷马多世—大平世早期)的海侵体系域(TST)有关。
Ordovician conodont biofacies of the upper La Silla and San Juan formations (middle Tremadocian-lower Dapingian) at Cerro La Silla, Argentine Precordillera
Conodonts from the upper La Silla (9.6 m thick) and San Juan formations (264.7 m thick) at the Cerro La Silla section are analyzed for the identification of faunal dynamics, biofacies and sea-level changes. The conodont collection of 11 388 specimens was recovered after digestion of 41 samples of carbonate rocks, totalizing 88.155 kg. Conodont total abundance and generic diversity graphs, as well as cluster analysis, reveal seven biofacies. The Colaptoconus, Tropodus-Reutterodus, Oepikodus-Prioniodus, Juanognathus-Bergstroemognathus, Juanognathus-Oepikodus-Protopanderodus, Juanognathus-Protopanderodus, Juanognathus-Semiacontiodus biofacies are determined. These biofacies represent middle to outer carbonate ramp environments for the San Juan Formation. The associated analysis of biofacies and lithology allow for the recognition of two transgressive events in the San Juan Formation at the Cerro La Silla section, which could be related to transgressive systems tracts (TST) that occurred during the Early and Middle Ordovician (middle Tremadocian-early Dapingian).
期刊介绍:
Comptes Rendus Palevol is a fully electronic and peer-reviewed journal, with a continuous publication stream, devoted to palaeontology, prehistory and evolutionary sciences. It publishes original research results, in French or English, in the following domains: systematic and human palaeontology, prehistory, evolutionary biology and macroevolution, and history of sciences. Thematic issues may also be published under the responsibility of a guest editor. All articles published in Comptes Rendus Palevol are compliant with the different nomenclatural codes. A copyright assignment will be signed by the authors before publication.