Precise position of the Basal Choteč event and evolution of sedimentary environments near the Lower–Middle Devonian boundary: The magnetic susceptibility, gamma-ray spectrometric, lithological, and geochemical record of the Prague Synform (Czech Republic)

0359029 - GLÚ 2012 RIV NL eng J - Článek v odborném periodiku
Koptíková, Leona
Precise position of the Basal Choteč event and evolution of sedimentary environments near the Lower–Middle Devonian boundary: The magnetic susceptibility, gamma-ray spectrometric, lithological, and geochemical record of the Prague Synform (Czech Republic).
Palaeogeography, Palaeoclimatology, Palaeoecology. Roč. 304, 1/2 (2011), s. 96-112. ISSN 0031-0182. E-ISSN 1872-616X
Grant CEP: GA AV ČR KJB307020602; GA AV ČR IAAX00130702
Výzkumný záměr: CEZ:AV0Z30130516
Klíčová slova: magnetic susceptibility * Gamma-ray spectrometry * Prague Synform * Lower–Middle Devonian
Kód oboru RIV: DB - Geologie a mineralogie
Impakt faktor: 2.392, rok: 2011

Basal Choteč Event (close the Lower–Middle Devonian boundary, Prague Synform) has distinct correlatable magnetic susceptibility (MS), gamma spectrometric (GRS), and geochemical patterns. The MS record produces a smooth curve below the first event-related beds and a rapid increase in MS values with oscillations above. The GRS record shows a reversal in the Th to U ratio at the event base from values above 1 to below 1. REE distributions show very uniform patterns indicative of their aeolian origin. A similar trend is displayed both in the deeper- and shallow-water environments. Light and heavy mineral assemblages are dominated by dia-, paramagnetic (kaolinite, chlorite, pyroxene/amphiboles, apatite, barite, feldspars, muscovite) and ferromagnetic minerals(Fe oxides-oxyhydroxides). The MS and GRS data, together with the lithology(calcisiltic hemipelagic material below the event base and recycled skeletal detritus from turbidite currents above),suggest the sea-level rise at event interval.
Trvalý link: http://hdl.handle.net/11104/0196904