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Dynamic Linkages Between Stratigraphy, Climate, Oceanography, and Biotic Events in the Middle Silurian of Eastern Laurentia- [electronic resource]
Dynamic Linkages Between Stratigraphy, Climate, Oceanography, and Biotic Events in the Middle Silurian of Eastern Laurentia- [electronic resource]
상세정보
- 자료유형
- 학위논문(국외)
- 자관 청구기호
- 기본표목-개인명
- 표제와 책임표시사항
- Dynamic Linkages Between Stratigraphy, Climate, Oceanography, and Biotic Events in the Middle Silurian of Eastern Laurentia - [electronic resource] / Thomka, James Robert.
- 발행, 배포, 간사 사항
- 형태사항
- 1 online resource(465 p)
- 일반주기
- Source: Dissertation Abstracts International, Volume: 77-07(E), Section: B.
- 학위논문주기
- Thesis (Ph.D.)--University of Cincinnati, 2015.
- 요약 등 주기
- 요약The late Llandovery-early Wenlock (middle Silurian) is increasingly recognized as one of the most perturbed intervals of the Paleozoic, characterized by rapid, nearly concurrent disruptions to a variety of biotic and abiotic systems. A previously unrecognized signature of regional and global instability is the occurrence of an anachronistic echinoderm fauna in eastern Laurentia that is genetically linked to coincident disturbances; unraveling the factors controlling the establishment of this blastozoan-dominated fauna contributes to a refined understanding of the dynamic evolution of middle Silurian climate, oceanography, stratigraphy, and paleoecology.
- 요약 등 주기
- 요약As part of a large-scale faunal invasion, an exceptionally diverse fauna of blastozoan echinoderms derived from Old World (Gondwanan, Baltican, Avalonian) lineages, including coronoids, hemicosmitid rhombiferans, and the diploporite Holocystites Fauna, invaded and flourished in the Cincinnati Arch region. At the Napoleon quarry of southeastern Indiana, these invasive taxa co-occur with the youngest documented representatives of Paracrinoidea and Eocrinoidea, as well as callocystitid rhombiferans and a blastoid. Hence, this fauna displays class-level diversity and a blastozoan:crinoid ratio characteristic of the Middle-early Late Ordovician and quite unlike the crinoid-dominated middle Silurian. The local success of this unusual fauna can be attributed in part to substrate irregularity, which permitted diverse attachment strategies, and in part to a complex taphonomic history, which favored preservation and concentration of articulated and identifiable diploporite thecae. Nevertheless, the anomalously high abundance and diversity of non-crinoid echinoderms was predominantly controlled by extrinsic paleoenvironmental factors.
- 요약 등 주기
- 요약The establishment of the Holocystites Fauna and associated blastozoans does not occur in the immediate aftermath of an extinction event within Crinoidea or removal of other sessile suspension-feeders, and does not correspond to decreased predation. Convergent lines of evidence indicate a genetic link to a short-lived early Sheinwoodian glaciation that led to establishment of cool, nutrient-rich waters that impinged on areas of positive relief, leading to locally increased primary productivity. This abundance of food for suspension-feeding organisms allowed the relatively efficient camerate crinoids to thrive, as they did in most middle Silurian shallow marine settings, but also led to a dramatically increased proportion of taxa with less efficient feeding structures that were largely excluded from such environments by late Llandovery.
- 요약 등 주기
- 요약The middle Silurian perturbed interval was initially characterized by un-glaciated conditions, low carbon isotope values, and high sea levels further elevated by a minor episode of tectonic activity. This exceptionally high sea level opened up biogeographic corridors into Laurentia from other paleocontinents, leading to an early phase of the late Telychian faunal invasion. The shift to early Sheinwoodian glaciated conditions is marked by redox and shale-marl rhythms, biological turnover in certain clades, and, eventually, relative sea-level fall. Echinoderms from higher latitudes invaded Laurentia at this point, before highstand biogeographic corridors were closed off. Sheinwoodian glaciated conditions are characterized by growth of micritic mud-mounds, high carbon isotope values, and anachronistic echinoderms, reflecting altered paleoceanographic conditions (i.e., small and large scale climatically generated changes in productivity). With later Sheinwoodian climatic amelioration, widespread, massive skeletal carbonates were deposited across both sides of the Appalachian Foreland Basin.
- 주제명부출표목-일반주제명
- 부출표목-단체명
- 기본자료저록
- Dissertation Abstracts International. 77-07B(E).
- 기본자료저록
- Dissertation Abstract International
- 전자적 위치 및 접속
- 원문정보보기
- 소장사항
-
20170404 2017
MARC
008170601s2015 us esm 001c eng■001MOKWON01251211
■00520170418113703
■007cr
■020 ▼a9781339435046
■035 ▼a(MiAaPQ)AAI10005426
■040 ▼aMiAaPQ▼cMiAaPQ
■090 ▼a전자도서(박사논문)
■1001 ▼aThomka, James Robert.
■24510▼aDynamic Linkages Between Stratigraphy, Climate, Oceanography, and Biotic Events in the Middle Silurian of Eastern Laurentia▼h[electronic resource]▼cThomka, James Robert.
■260 ▼a[Sl]▼bUniversity of Cincinnati▼c2015
■300 ▼a1 online resource(465 p)
■500 ▼aSource: Dissertation Abstracts International, Volume: 77-07(E), Section: B.
■5021 ▼aThesis (Ph.D.)--University of Cincinnati, 2015.
■520 ▼aThe late Llandovery-early Wenlock (middle Silurian) is increasingly recognized as one of the most perturbed intervals of the Paleozoic, characterized by rapid, nearly concurrent disruptions to a variety of biotic and abiotic systems. A previously unrecognized signature of regional and global instability is the occurrence of an anachronistic echinoderm fauna in eastern Laurentia that is genetically linked to coincident disturbances; unraveling the factors controlling the establishment of this blastozoan-dominated fauna contributes to a refined understanding of the dynamic evolution of middle Silurian climate, oceanography, stratigraphy, and paleoecology.
■520 ▼aAs part of a large-scale faunal invasion, an exceptionally diverse fauna of blastozoan echinoderms derived from Old World (Gondwanan, Baltican, Avalonian) lineages, including coronoids, hemicosmitid rhombiferans, and the diploporite Holocystites Fauna, invaded and flourished in the Cincinnati Arch region. At the Napoleon quarry of southeastern Indiana, these invasive taxa co-occur with the youngest documented representatives of Paracrinoidea and Eocrinoidea, as well as callocystitid rhombiferans and a blastoid. Hence, this fauna displays class-level diversity and a blastozoan:crinoid ratio characteristic of the Middle-early Late Ordovician and quite unlike the crinoid-dominated middle Silurian. The local success of this unusual fauna can be attributed in part to substrate irregularity, which permitted diverse attachment strategies, and in part to a complex taphonomic history, which favored preservation and concentration of articulated and identifiable diploporite thecae. Nevertheless, the anomalously high abundance and diversity of non-crinoid echinoderms was predominantly controlled by extrinsic paleoenvironmental factors.
■520 ▼aThe establishment of the Holocystites Fauna and associated blastozoans does not occur in the immediate aftermath of an extinction event within Crinoidea or removal of other sessile suspension-feeders, and does not correspond to decreased predation. Convergent lines of evidence indicate a genetic link to a short-lived early Sheinwoodian glaciation that led to establishment of cool, nutrient-rich waters that impinged on areas of positive relief, leading to locally increased primary productivity. This abundance of food for suspension-feeding organisms allowed the relatively efficient camerate crinoids to thrive, as they did in most middle Silurian shallow marine settings, but also led to a dramatically increased proportion of taxa with less efficient feeding structures that were largely excluded from such environments by late Llandovery.
■520 ▼aThe middle Silurian perturbed interval was initially characterized by un-glaciated conditions, low carbon isotope values, and high sea levels further elevated by a minor episode of tectonic activity. This exceptionally high sea level opened up biogeographic corridors into Laurentia from other paleocontinents, leading to an early phase of the late Telychian faunal invasion. The shift to early Sheinwoodian glaciated conditions is marked by redox and shale-marl rhythms, biological turnover in certain clades, and, eventually, relative sea-level fall. Echinoderms from higher latitudes invaded Laurentia at this point, before highstand biogeographic corridors were closed off. Sheinwoodian glaciated conditions are characterized by growth of micritic mud-mounds, high carbon isotope values, and anachronistic echinoderms, reflecting altered paleoceanographic conditions (i.e., small and large scale climatically generated changes in productivity). With later Sheinwoodian climatic amelioration, widespread, massive skeletal carbonates were deposited across both sides of the Appalachian Foreland Basin.
■590 ▼aSchool code: 0045.
■650 4▼aGeology
■690 ▼a0372
■71020▼aUniversity of Cincinnati▼bArts and Sciences: Geology.
■7730 ▼tDissertation Abstracts International▼g77-07B(E).
■773 ▼tDissertation Abstract International
■790 ▼a0045
■791 ▼aPh.D.
■792 ▼a2015
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T14487067▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
■980 ▼a20170404▼f2017
