New data on the Vrancea Nappe (Moldavidian Basin, Outer Carpathian Domain, Romania): paleogeographic and geodynamic reconstructions

Abstract

A study has been performed on the Cretaceous to Early Miocene succession of the Vrancea Nappe (Outer Carpathians, Romania), based on field reconstruction of the stratigraphic record, mineralogical-petrographic and geochemical analyses. Extra-basinal clastic supply and intrabasinal autochthonous deposits have been differentiated, appearing laterally inter-fingered and/or interbedded. The main clastic petrofacies consist of calcarenites, sub-litharenites, quartzarenites, sub-arkoses, and polygenic conglomerates\ud derived from extra-basinal margins. An alternate internal and external provenance of the different supplies is the result of the paleogeographic re-organization of the basin/margins system due to tectonic activation and exhumation of rising areas. The intra-basinal deposits consist of black shales and siliceous sediments (silexites and cherty beds), evidencing major environmental changes in the Moldavidian Basin. Organic-matter-rich black shales were deposited during anoxic episodes related to sediment starvation and high nutrient influx due to paleogeographic isolation of the basin caused by plate drifting. The black shales display relatively high contents in sub-mature to mature, Type II lipidic organic matter (good oil and gas-prone source rocks) constituting a potentially active petroleum system.\ud The intra-basinal siliceous sediments are related to oxic pelagic or hemipelagic environments under tectonic quiescence conditions although its increase in the Oligocene part of the succession can be correlated with volcanic supplies.\ud The integration of all the data in the ‘‘progressive reorientation of convergence direction’’ Carpathian model, and their consideration in the framework of a foreland basin, led to propose some constrains on the paleogeographic-geodynamic evolutionary model of the Moldavidian Basin from the Late Cretaceous to the Burdigalian

Paratethyan Petroleum Source Rocks: An Overview

“…Miclăus et al, 2009). Unfortunately the precise age of the Menilite Formation is still a matter of debate (see Melinte, 2005;Melinte-Dobrinescu and Bustur;, Amadori et al, 2012Guerrera et al, 2012;Sachsenhofer et al, 2015).…”

Evolutionary Models of the Cenozoic Basins of Central-Western Mediterranean Area: A Review of Methodological Approaches

“…These sections synthetically show the main crustal elements (oceans, continents and sedimentary covers); subduction planes; main tectonic movements; and orogenic phases. Relationships between microplates and basins, tectonic transport, and opening and closing of basins are also shown (data from [9,21,31,37,69,77,78]). In the reconstruction the Tethyan oceanic branch recently recognized in the External Domain of the Rif Chain ( [35,[79][80][81]) was interpreted as an oceanic branch sector located between the External zones of the Mesorif and Intrarif Domains connected to the Maghrebian Flysch Domain [82].…”

Dinoflagellate cysts and palynofacies across the Cretaceous-Paleogene boundary interval of the Vrancea Nappe (Eastern Carpathians, Romania)

“…This olistostrome bed is over lain by the Putna-Piatra Uscatã For ma tion (180 m thick; Lower Paleocene-up per most Ypresian; Grasu et al, 1988;Guerrera et al, 2012), con sist ing of lam i nated black shales with lime stone in ter ca la tions (up to 4-5 m thick), arenites and calcarenites. The geo log i cal sec tion along the Runcu River ends with the Bisericani For ma tion (Priabonian-Lower Rupelian; Amadori et al, 2012).…”