Age Assignment of the Erin Slate, Talladega Slate Belt, Clay County, Alabama

阿拉巴马州克莱县塔拉迪加板岩带艾琳板岩的年龄分配

• 批准号: 9019286
• 负责人: Robert Gastaldo
• 金额: $ 3.2万
• 依托单位: Auburn University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-03-01 至 1992-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9019286&HistoricalAwards=false
• 关键词: Age; Assignment; Erin; Slate; Talladega

A controversy exists surrounding the age assignment of the Erin Slate, outcropping in the Talladega Slate Belt of Alabama. The age assignment of this unit has become pivotal in the paleotectonic interpretation and timing of emplacement of the Talladega slate belt in the southern Appalachian orogen. The disputed age assignment of the Erin Slate is based on the reported presence of permineralized Carboniferous lycophyte cones, Lepidostrobus hobbsii D. White. Subsequent workers were unable to collect additional permineralized fossil plants, although compression-impressions have been documented in the matrix and an indistinguishable petrologic similarity between the Erin Slate and matrix adhering to one of the cones exists. The lack of subsequently collected material, equal in preservational mode and type to that of the original two lycophyte cones, has led some workers to question the validity of a fossiliferous Erin. The original plant fossils are currently considered to be "exotics", and the Erin Slate has been lithostratigraphically correlated with the Early Devonian Jemison Chert. Newly discovered permineralized plant fossils provide unequivocal evidence that the Erin slate is fossiliferous. The project herein proposed is designed to assess this newly recovered paleobotanical evidence for a definitive age assignment of the Erin Slate and its regional correlatives. The taxonomic diversity and systematic affinities of this permineralized flora will be ascertained and compared with those plants of homologous structural advancement, paleogeographic distribution, and biostratigraphic position. The age assignment based on the constraints of the paleobotanical evidence will form the foundation for evaluating the tectonic setting of the Erin Slate and its relationship to the tectonic framework now proposed for the southern Appalachians.//

围绕年龄分配存在争议， 艾琳石板，在亚拉巴马的塔拉德加石板带露头。 这个单位的年龄分配已成为关键， 古构造解释和侵位时间 阿巴拉契亚造山带南部的塔拉德加板岩带。 的 有争议的年龄分配的艾琳石板是基于报告 存在过矿化的石炭纪石松球果， 霍氏鳞松白色。 后来的工人无法 收集更多的化石植物，虽然 压缩压痕已记录在矩阵中， 埃林板岩和 存在附着在其中一个锥体上的基质。 缺乏 随后收集的材料，在平行模式下相等， 类型到原来的两个石松球果，导致了一些 工人们质疑一个充满活力的艾琳的有效性。 的 原始植物化石目前被认为是“外来物种”， 而埃林板岩的岩石地层与 早泥盆世杰米森燧石 新发现的过矿化 植物化石提供了明确的证据，表明埃林板岩是 充满活力。 本文提出的项目旨在评估 新发现的古植物学证据表明 Erin Slate及其区域相关物的分配。 的 分类多样性和系统亲缘关系 确定矿化植物群，并与 同源结构进化的植物，古地理的 分布和生物地层位置。 年龄分配 基于古植物学证据的限制， 评价埃林构造环境的基础 板岩及其与构造格架的关系 阿巴拉契亚山脉南部