000 02909nmc a2200229 4500
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082 _aCD I116 64 0015469
245 0 0 _aTrazadores diagenéticos de las paleomigraciones de hidrocarburos en las areniscas rojas cretácicas del Grupo Neuquén, Cuenca Neuquina
270 _a03/10/2016 ; 03/10/2016
300 _a20 p.
520 _aDiagenetic tracers of hydrocarbon paleo-migratios in Cretaceous red beds of the Neuquén Group, Neuquén Basin Striking arrangement of colorful facies in the sandstones outcrops of the Candeleros, Huincul, and Portezuelo formations at Los Chihuidos high (Neuquén Group) and at the Huincul Ridge has been attributed to the surface expression of hydrocarbon-induced alteration. According to visual distinctions, four diagenetic facies have been recognized: red, white, gray, and brown sandstones. Differences in the mineralogy between sandstones facies depend on the degree of interaction with hydrocarbon-bearing solutions and the relative position of the redox roll front developed during this process. The red facies represents the original oxidized sandstones with hematite, kaolinite or corrensite, quartz and albite overgrowths, and calcite cement precipitated under oxidizing conditions during the regional burial diagenesis. The white facies formed during the interaction of red beds with hydrocarbons-organic acids, where clasts and cement were partially dissolved, iron was reduced to Fe2+ and removed or precipitated as pyrite, resulting in the sandstone decoloration and in a notorious enhancement of the secondary porosity. Only minor montmorillonite precipitated replacing kaolinite and detrital feldspars and multistage calcite filling the pores. The gray and the brown sandstones locally bound the redox front with abundant clay and oxide minerals. Montmorillonite and secondary hematite are dominant in the more oxidized gray sandstones whereas interstratified chlorite-montmorillonite is more abundant in the more reduced brown sandstones. The coexistence of these minerals indicates metastable reducing-oxidizing conditions at the redox front. This multi-scale study of patterns of bleaching in a succession of clastic rocks allowed the definition of a redox system at regional scale linked to structure controlled upflow of hydrocarbons and associated fluids, and the chemical reactions between reducing fluids and diagenetic minerals.
773 _g
942 _cCONGTP
100 1 _aFranchini, Marta
_955663
100 1 _aRainoldi, Ana
_955675
100 1 _aPons, Josefina
_955676
100 1 _aGiusiano, Adolfo
_955677
111 2 _aCongreso de Exploración y Desarrollo de Hidrocarburos (9no. : 2014 nov. 3-7 : Mendoza)
_954287
999 _c189765
_d189765
856 _uhttps://biblioteca.iapg.org.ar/ArchivosAdjuntos/CONEXPLOR2014/203-Trazadoresdiageneticos.pdf