کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4466758 1622218 2012 17 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Palaeoecology of transported brachiopod assemblages embedded in black shale, Cape Phillips Formation (Silurian), Arctic Canada
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Palaeoecology of transported brachiopod assemblages embedded in black shale, Cape Phillips Formation (Silurian), Arctic Canada
چکیده انگلیسی

Brachiopod communities have been widely used for palaeoecological studies and reconstruction of sea-level changes in Earth history. Previous studies of brachiopod communities emphasised sampling benthic shelly fossils preserved in situ to avoid preservation bias. Silurian (Wenlock) brachiopod assemblages are well preserved as debris-turbidity flows, including calcareous concretions, embedded in thick sequences of black shale of the Cape Phillips Formation, with a mixture of deep-water brachiopods and transported shallow-water forms. In this study, the first attempt is made to use the transported assemblages to reconstruct Silurian brachiopod communities that once lived along a palaeogradient from the shallow-water Arctic Platform to the deep-water Franklinian Basin. Seven transported brachiopod assemblages were recognised using multivariate analyses (cluster analysis and principal components analysis), with varying ratios of shallow- versus deep-water shells, segregated according to their known palaeobathymetric ranges in other regions. The Wenlock–early Ludlow sea-level fluctuations in the study area, reconstructed using the percentage values of shallow- and deep-water brachiopod specimens as a proxy, have a high degree of agreement with the Arctic Silurian sea-level curve and moderate agreements with global sea-level histories of other regions such as the British Isles and Gotland interpreted from graptolite abundance and diversity changes, and sequence and event stratigraphical methods, respectively.

Figure optionsDownload high-quality image (198 K)Download as PowerPoint slideHighlights
► Silurian brachiopod assemblages are rich and diverse in debris flow deposits.
► Ratio of transported shallow vs. deep-water taxa is related to shoreline proximity.
► Silurian sea-level curve is reconstructed using brachiopod assemblages as proxy.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Palaeogeography, Palaeoclimatology, Palaeoecology - Volumes 367–368, 15 December 2012, Pages 104–120
نویسندگان
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