- Tytuł:
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Porównanie podatności magnetycznej (MS) i wskaźników geochemicznych środkowego i górnego franu w Kanadyjskich Górach Skalistych: implikacje dla analiz paleoklimatycznych i paleośrodowiskowych oraz interpretacji zdarzenia punctata
Comparison of magnetic susceptibility (MS) and other geochemical proxies from the Middle-Late Frasnian of the Canadian Rocky Mountains: implication for paleoenvironmental and paleoclimatic analyses and interpretations of the punctata Event - Autorzy:
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Śliwiński, M. G.
Whalen, M.
Day, J. - Powiązania:
- https://bibliotekanauki.pl/articles/2074752.pdf
- Data publikacji:
- 2010
- Wydawca:
- Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
- Tematy:
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późny dewon
podatność magnetyczna
zdarzenie punctata
pierwiastki śladowe
wycieczka geochemiczna
izotopy trwałe
zbiorniki osadowe Kanady zachodniej
Late Devonian
magnetic susceptibility
punctata Event
trace elements
stable isotopes
Western Canada Sedimentary Basin - Opis:
- Ongoing magnetostratigraphic and geochemical studies (including major and trace element geochemistry and stable isotopes of C, N, O) in the Canadian Rocky Mountains are providing insight into the paleoenvironmental changes of the mid-Frasnian punctata Event, a prominent marine geochemical perturbation. The data is evaluated with 1) a regional sequence stratigraphic perspective and 2) within the context of a rapidly changing Late Devonian world, characterized by numerous sedimentological and faunal perturbations leading up to the eventual Frasnian-Fammenian (F/F) mass extinction. Proxies for bottom water paleoredox conditions (Mo, V, U), oceanic primary productivity (δ13Corg, δ15Nbulku, Cu, Ni, Ba), changes in detrital input (Si, Al, K, Ti, Zr), and magnetic susceptibility display similar trends, indicating that these proxies and MS variations are inherently linked. The observed excursions suggest that changes in detrital input were the main driver of a bioproductivity increase. Elevated organic matter export from the photic zone likely led to the deposition and later preservation of organic-carbon rich facies under facilitated conditions of bottom water suboxia-anoxia. These geochemical trends were likely influenced by eustatic sea level change, but may have been enhanced by pulses of coincident orogenic activity and pulses of terrestrial afforestation. The rise and expansion of the first true forests is thought to have drastically altered nutrient fluxes to the oceans via increases in pedogenesis and the expansion of a mature soil profile. Our work is intended to complement the growing body of research aimed at elucidating the causes and understanding the effects of terrestrial and marine events of the P. punctata biozone and, more broadly, at understanding the Earth-system changes of the Late Devonian leading up to the F/F boundary.
- Źródło:
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Przegląd Geologiczny; 2010, 58, 12; 1152-1160
0033-2151 - Pojawia się w:
- Przegląd Geologiczny
- Dostawca treści:
- Biblioteka Nauki
Artykuł