Geology of the Danube Delta

The Danube Delta is located, in geological terms, in a region of crust mobile platform called Delta (region predobrogeană). Delta platform comes into contact with the south-western North Dobrogea orogen by Oancea fault-St. George, which is roughly parallel to the St. George arm.

Its geological structure is composed of a crystalline foundation over which has a transgressive sedimentary sequence represented by deposits Paleozoic, Triassic, Jurassic, Cretaceous, Neogene and Quaternary, induced by large and shallow drilling conducted in the area. Deposits of Paleozoic age, the floors are Silurian-Permian (438-230 million years ago), consist of limestone, dolomite, silt, lithic sandstones, with intercalations of tuffs vitroclastice.

Triassic deposits (248-213 million years) are formed at the base of ferruginous silt, clay, sandstone, microconglomerates with intercalations feldspathic Gates, diabase and melafire and transgressive occurring dolomite, sandstone, limestone, silt, marl AND . a. containing plant species (Striatoabietites sp. Ovalipollis Oval etc.), foraminifers (Glomospirella sp. Spirillina sp. etc.), conodonde (Gondolella navicula, Gladiogondolella tethydis etc.).

Deposits of Jurassic age (ages Dogger-Malm - 176-142 million years) are mainly composed of limestone (the base), clay, limestone, sandstone, limestone and gray and yellow (on top), with fossil foraminifers ( Textularia Jurassic, Spirillina orbicula etc.) dinofagelate (Nannoceceratopsis spicula, N. pellucida, Ctenidodinium panneum etc.), etc.. Cretaceous deposits belonging floors Apţian-Senonian (121-65 million years) are composed mainly of ferruginous clay and silt with intercalations of fine sandstones and dolomites gipsifere, containing a poor phytocoenosis Trilobosporilites apiverucatus, triplex Clavifera etc..

Neogene age deposits (Sarmatian-Romanian floors - from 13.5 to 1.8 million years) are composed of a succession of layers with lumaşelice limestone, sand, silt and clay, with Mactra sp., Sand, silt and clay reddish with Dosinia maeotica, fine gray sand (with Dreissena rimestiensis, Limnocardium sp. Stylodacna orientalis sands and sands with clay intercalations, containing specimens bifarcinatus viviparus, etc. Dreissena polymorpha.

Quaternary age deposits (deltaic deposits belonging to the Pleistocene-Holocene floors - 1.8 to 0.01 million years) are formed at the base, a brick-red clay layer followed by a succession of layers of gravel, sand , silt, clay and loess, and silt at the top is available for fluvial and fluvial-lacustrine origin.