| mhorn | Дата: Wednesday, 28.11.2012, 20:59 | Сообщение # 1 |
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| Vicente J.-C. (2012) Paleogeografía dinámica del margen cratónico durante el Jurásico marino a nivel de la Alta Cordillera de San Juan y Mendoza: paleoambientes y cambios de facies // Revue de Paléobiologie, Genève, Vol. spéc. 11. P.113-131
pdf: http://www.ville-ge.ch/mhng/paleo/paleo-pdf/spec-11/pal-spec-11-10.pdf
From a set of key stratigraphic sections of the marine Jurassic deposits from the High Cordillera of San Juan and Mendoza provinces (Argentina), logged between 31°30’ and 33°00’S, paleoceanographic profiles and paleogeographic maps spanning the Pliensbachian-Oxfordian interval are presented. With good stratigraphic control and a wealth of microfacies analyses, but confronted with great facies changes, both across and latitudinally, facies and ages were favoured at the expense of an imported lithostratigraphic nomenclature which could risk concealing diachronic events. According to the age of the transgression on one hand and that of the regression on the other, five virtual local series are defined to illustrate the main series type observed. The used virtual series notion is in agreement with the quite continuous character of sedimentation and the lack of notable discontinuities. On this basis the general facies evolution is analysed from the transgression deposits to the pure marine phases and the final stages of concentration of soluble salts in the water. The identified main paleoenvironments are sorted out according to their benthic thanatocoenoses and sedimentary characteristics. Comparison with recent environments leads to a relative paleobathymetry, which allows a fairly precise reconstruction of the coast line fluctuations and of the evolutionary dynamics of facies on that cratonic margin during the considered sedimentary cycle
Middle Jurassic - Lower Cretaceous ammonites & aptychi
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