| mhorn | Дата: Thursday, 01.08.2013, 18:40 | Сообщение # 1 |
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| Bádenas, B., Armendáriz, M., Rosales,I., Aurell. M., Piñuela, L., García-Ramos J.C. (2013) Origen de los black shales del Pliensbachiense inferior de la Cuenca Asturiana (España) // Revista de la Sociedad Geológica de España, 26 (1), 41-54.
http://www.sociedadgeologica.es/archivos/REV/26(1)/art03.pdf
Lower Pliensbachian (Ibex Zone) black shales in the Asturian Basin (N Spain) represent “transgressive” black shales intercalated in relatively shallower (bioclastic and bioturbated) marine facies. Sedimentological and stable isotope analysis(O and C from belemnite rostra) and correlation between two 18 km apartstratigraphic sections at the Asturian sea-clifs (Playa de Vega: 4.4 m thick; Punta La Llastra: 7.8mthick) allowed characterizing vertical and lateral trends of black shale-, storm related bioclástic- and bioturbated muddy facies, within four sedimentary stages. The observed sedimentary trends have been mainly related to the interaction between: warming of superficial ocean water, long-term relative sea-level rise, and short-term tectonic pulses of differential subsidence controlling preferential accumulation of black shales in subsiding troughs. The comparison of available sedimentological and isotopic data from coeval sedimentary successions from other basins indicates at least a regional extension of the warming event (i.e. European and Nortwest Tethys basins). The slight diachroneity of the Lower Pliensbachian (Ibex Zone) black shales in the Asturian, Basque-Cantabrian and Lusitanian basins is probably reflecting the influence of the regional tectonic subsidence, which was superimposed to the long-term sea-level rise and the warming event
Middle Jurassic - Lower Cretaceous ammonites & aptychi
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