Late Devonian facies variety in Iran: volcanism as a possible trigger of the environmental perturbation
Year: 2004
Type: article
Abstract: possible trigger of the environmental perturbation near the Frasnian-Famennian boundary. Geol. Quart., 48 (4): 323–332. Warszawa. Upper Devonian successions surrounding the Frasnian-Famennian (F-F) boundary in Iran consist of mixed carbonate/silisiclastic depos-its. The successions are characterized by conspicuous ferruginous limestones, clay-rich units, black shales, and mafic volcanic rocks that provide important insights into palaeoenvironmental conditions during this interval of Earth’s history. An increase of kaolinite/illite ra-tio in clays associated with the F-F boundary suggests that increased chemical weathering was facilitated by warm and humid climatic conditions. Distinctive ferruginous-oolite deposits overlying the crucial Frasnian-Famennian boundary interval indicate a high supply rate of Fe-bearing clay originated during enhanced weathering under such climatic conditions. Black shales associated with the F-F boundary are interpreted to be the result of a high primary productivity caused by an increased influx of land-derived nutrients and re-gional volcanic activity. Widespread rift-related, basaltic activity along eastern Laurussia and northern Gondwana during the mid-Late Devonian is believed to have contribution to this global warming surrounding the F-F boundary.
Institution: The University of Tokyo
Language: English
Subfield: Paleontology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W2133406325