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The Neuquén Basin: Sequence Stratigraphy of Vaca Muerta Formation (view source)
Revision as of 16:09, 13 March 2019
, 16:09, 13 March 2019→Stratigraphy of Vaca Muerta Formation in El Trapial area
Three main facies has been determined in El Trapial area to describe Vaca Muerta Formation.
Three main facies has been determined in El Trapial area to describe Vaca Muerta Formation.
=== Facies 1: outer ramp restricted to basin ===
=== Facies 1: Outer ramp restricted to basin ===
[[File:3.png|400px|thumbnail|{{figure number|3}}Schematic section showing facies association A and B, by Tomassini et al.<ref name=Tomassini /> A) mixed ramp. B) siliciclastic platform.]]
[[File:3.png|400px|thumbnail|{{figure number|3}}Schematic section showing facies association A and B, by Tomassini et al.<ref name=Tomassini /> A) mixed ramp. B) siliciclastic platform.]]
According Tomassini et al.,<ref name=Tomassini /> the interpreted transport and sedimentation processes were strom events that put particles suspension and subsequent decanting. The absence of [[bioturbation]], dark colors, and bindstones suggest a low rate of sedimentation, low energy and low oxygen environment.
According Tomassini et al.,<ref name=Tomassini /> the interpreted transport and sedimentation processes were strom events that put particles suspension and subsequent decanting. The absence of [[bioturbation]], dark colors, and bindstones suggest a low rate of sedimentation, low energy and low oxygen environment.
=== Facies 2: outer ramp ===
=== Facies 2: Outer ramp ===
It is constituted by alternating marl with [[packstones]] and grainstones. Bioclastic concentrations are very similar to those of the previous facies for each lithology.
It is constituted by alternating marl with [[packstones]] and grainstones. Bioclastic concentrations are very similar to those of the previous facies for each lithology.
According Tomassini et al.,<ref name=Tomassini /> these facies are interpreted as an environment of outer ramp, where periods of storm and good weather prevailed.
According Tomassini et al.,<ref name=Tomassini /> these facies are interpreted as an environment of outer ramp, where periods of storm and good weather prevailed.
=== Facies 3: offshore- offshore transition ===
=== Facies 3: Offshore- offshore transition ===
Composed of laminated shales (few fish scales and bivalves) and interbedded silt and very fine sand .
Composed of laminated shales (few fish scales and bivalves) and interbedded silt and very fine sand .