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Three groups of unusual microfossils in the Pennsylvanian and Permian succession in midcontinent North America.

机译：北美洲中部宾夕法尼亚州和二叠纪演替中的三类不同寻常的微化石。

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摘要

This thesis includes descriptions of three unusual groups of microfossils from the Pennsylvanian and Permian succession of Midcontinent North America. Most of the locations were discovered during the examination of acid insoluble residues of shales and limestones, while working on various projects involving conodont biostratigraphy. Locations vary from near Des Moines, Iowa in the north, to northwest Missouri, eastern and south-central Kansas, and near Tulsa, Oklahoma in the south. Locations range in age from the Excello Shale in the upper Desmoinesian Stage (Pennsylvanian) to the Fort Riley Limestone in the lower Artinskian Stage (Permian). Fossil groups include radiolarians, chitinozoans, and chitinozoan-like organic-walled microfossils. All fossil groups contain very small individuals (62--2500mu) and require imaging by a scanning electron microscope (SEM) to identify and study morphology.; The radiolarians (Chapter I) represent the first known occurrence of abundant relatively well-preserved specimens from Midcontinent North America. The radiolarians are from the Excello Shale, lower Marmaton Group (Desmoinesian, Pennsylvanian) of south-central Iowa, and include pseudoalbaillellids and both spherical and stauraxon spumellarians.; The chitinozoans (Chapter II) were previously reported from the Leavenworth Limestone and Fort Riley Limestone (Virgilian and Artinskian stages respectively) of eastern Kansas, and this report extends the geographical range into northwest Missouri in the Larsh-Burroak Shale (Virgilian) and into northeastern Oklahoma in the Eudora Shale (Missourian). They include Rhabdochitina, Euconochitina, Lagenochitina, and Sphaerochitina of the Order Prosomatifera.; The chitinozoan-like organic-walled microfossils (Chapter III) were also previously reported from the Leavenworth Limestone (Virgilian) and the Fort Riley Limestone (Artinskian) of eastern Kansas, but they had never been described morphologically. They have also now been found in abundance in the lower Lane Shale (Missourian) of Iowa, Larsh-Burroak Shale (Virgilian) of Missouri, and lower Eudora Shale (Missourian) of Oklahoma. Their biological affinity is still unknown, but they may represent Polychaete worm egg cases.; All three groups of microfossils are related to their utility in biostratigraphy and to their position within transgressive-regressive sequences (cyclothems). Radiolarians and the organic-walled microfossils occur in abundance only in facies of the highstand system tract, while the chitinozoans occur as rare fossils in all system tracts. Only the radiolarians seem useful in biostratigraphic correlation, and paleogeographic reconstruction.
机译：本文包括对北美中部宾夕法尼亚州和二叠纪演替过程中三个不同寻常的微化石群的描述。大多数位置是在检查页岩和石灰石的酸不溶性残留物时发现的，同时进行了涉及牙形石生物地层学的各种项目。地点从北部的爱荷华州得梅因附近，密苏里州的西北部，堪萨斯州的中部和南部到南部的俄克拉荷马州塔尔萨不等。年龄范围从上Desmoinesian阶段的Excello页岩（宾夕法尼亚）到Artinskian阶段下部的二叠纪Fort Riley石灰岩（二叠纪）。化石群包括放射虫，甲壳动物和类似甲壳动物的有机壁微化石。所有化石群都非常小（62--2500mu），需要通过扫描电子显微镜（SEM）成像才能识别和研究形态。放射虫（第一章）是北美中部地区相对完好的保存完好的标本的第一个已知事件。放射虫来自爱荷华州中南部的下马尔马顿群（得克萨斯州，宾夕法尼亚州）的埃克塞洛页岩，包括假伞形目动物以及球形和星状浮游生物。先前曾从堪萨斯州东部的莱文沃思石灰岩和莱利堡石灰岩（分别为维吉尔和阿廷斯基阶段）报道了甲壳动物（第二章），并且该报告将地理范围扩展到了拉什-巴鲁克页岩（维吉尔）的密苏里西北部和东北部。俄克拉荷马州的尤多拉页岩（密苏里州）。它们包括肉食目的Rhabdochitina，Euconochitina，Lagenochitina和Sphaerochitina。以前也曾从堪萨斯州东部的莱文沃思石灰岩（维吉尔人）和莱利堡石灰岩（阿尔丁斯基）石灰岩中发现过类似甲壳动物类的有机壁微化石（第三章），但从未进行过形态学描述。现在，在爱荷华州下巷页岩（密苏里州），密苏里州拉尔什-布罗克页岩（维吉尔）和俄克拉荷马州下尤多拉页岩（密苏里州）也大量发现了它们。它们的生物亲和力仍然未知，但它们可能代表多毛蠕虫卵病例。这三组微化石都与它们在生物地层学中的用途以及它们在海侵序列之间的位置有关。放射虫和有机壁微化石仅在高位系统道的相中大量存在，而甲壳动物在所有系统道中均以稀有化石的形式出现。只有放射虫似乎对生物地层相关和古地理重建有用。

著录项

  • 作者

    Pope, John Paul.;

  • 作者单位

    The University of Iowa.;

  • 授予单位 The University of Iowa.;
  • 学科 Geology.; Paleontology.
  • 学位 Ph.D.
  • 年度 2006
  • 页码 173 p.
  • 总页数 173
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 地质学;古生物学;
  • 关键词

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