Title: Hierarchy of Factors Controlling Faunal Distribution: A Case Study from the Ordovician of the Argentine Precordillera
Abstract: Other| August 01, 2002 Hierarchy of Factors Controlling Faunal Distribution: A Case Study from the Ordovician of the Argentine Precordillera TERESA M. SÁNCHEZ; TERESA M. SÁNCHEZ 1Cátedra de Estratigrafía y Geología Histórica, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba. Av. Velez Sársfield 299, 5000 Córdoba, Argentina, CONICET Search for other works by this author on: GSW Google Scholar MARCELO G. CARRERA; MARCELO G. CARRERA 1Cátedra de Estratigrafía y Geología Histórica, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba. Av. Velez Sársfield 299, 5000 Córdoba, Argentina, CONICET Search for other works by this author on: GSW Google Scholar BEATRIZ G. WAISFELD BEATRIZ G. WAISFELD 1Cátedra de Estratigrafía y Geología Histórica, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba. Av. Velez Sársfield 299, 5000 Córdoba, Argentina, CONICET Search for other works by this author on: GSW Google Scholar Author and Article Information TERESA M. SÁNCHEZ 1Cátedra de Estratigrafía y Geología Histórica, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba. Av. Velez Sársfield 299, 5000 Córdoba, Argentina, CONICET MARCELO G. CARRERA 1Cátedra de Estratigrafía y Geología Histórica, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba. Av. Velez Sársfield 299, 5000 Córdoba, Argentina, CONICET BEATRIZ G. WAISFELD 1Cátedra de Estratigrafía y Geología Histórica, Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba. Av. Velez Sársfield 299, 5000 Córdoba, Argentina, CONICET Publisher: SEPM Society for Sedimentary Geology Accepted: 04 Feb 2002 First Online: 03 Mar 2017 Online ISSN: 1938-5323 Print ISSN: 0883-1351 Society for Sedimentary Geology PALAIOS (2002) 17 (4): 309–326. https://doi.org/10.1669/0883-1351(2002)017<0309:HOFCFD>2.0.CO;2 Article history Accepted: 04 Feb 2002 First Online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation TERESA M. SÁNCHEZ, MARCELO G. CARRERA, BEATRIZ G. WAISFELD; Hierarchy of Factors Controlling Faunal Distribution: A Case Study from the Ordovician of the Argentine Precordillera. PALAIOS 2002;; 17 (4): 309–326. doi: https://doi.org/10.1669/0883-1351(2002)017<0309:HOFCFD>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyPALAIOS Search Advanced Search Abstract Limiting factors affecting faunal distribution in the Ordovician rocks of the Precordillera basin, western Argentina, are analyzed and tentatively established. Eight biotic intervals ranging from the Tremadoc to the Ashgill are defined based upon the distribution in time and space of articulate brachiopod, trilobite, sponge, and bryozoan genera. High magnitudes of turnover are recognized on the basis of vertical ranges of taxa; this observation also is supported by low indices of carryover and holdover. Times of high faunal change define boundaries between the biotic intervals. Abiotic constraints largely prevail over ecological factors in controlling most substantial shifts in faunal composition and distribution at the interval boundaries. Taxonomic composition through different intervals is consistent with a change in paleobiogeographic affinities throughout the Ordovician, from markedly Laurentian affinities in the lowermost Ordovician to increasing Gondwanic affinities towards the Middle and Late Ordovician. At a smaller scale, the development of successive intervals is overprinted strongly by changes in facies and tectonic-induced setting. The composition and structure of assemblages were modified dramatically in the late Arenig-early Llanvirn with the changeover from sponge and brachiopod-dominated assemblages to brachiopod and trilobite-dominated assemblages with abundant bryozoans. This change occurs in consort with a shift from carbonate facies to mixed carbonate-siliciclastic and exclusively siliciclastic facies, and is considered to be the result of sea-level rise and the development of subsiding depocenters in the northern and southern parts of the Precordillera basin. On paleoecological grounds, this episode has allowed the biotic intervals to be grouped in two distinct stages. The lower stage includes intervals 1 to 3, whereas the upper stage includes intervals 6 to 8; intervals 4 and 5 represent the diachronous arrangement of both types of assemblages due to the gradual southward flooding of the basin. Abiotic factors acted at different temporal and spatial scales. Hence, their effect on faunal composition is explained best by distinguishing hierarchical levels of incidence. On this basis, three major hierarchical levels of factors are proposed. The general context in which faunas developed is provided by the shifting position of the Precordillera terrane throughout the Ordovician; accordingly, a first-order hierarchical level is represented by paleogeographic position. The second-order level is represented by the combined effects of rapid sea-level rise and basin deepening, with a high paleoecological impact on the fauna. The third-order level includes single factors producing minor changes in otherwise stable community structures (e.g., minor sea-level changes, fluctuations in water temperature, different facies types). You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Publication Year: 2002
Publication Date: 2002-08-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 8
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