%0 Journal Article
%T Deformaci車n, vetas, inclusiones fluidas y la evoluci車n tect車nica de las rocas cret芍cicas de Valle de Bravo, Estado de M谷xico, M谷xico
%A Fitz-D赤az
%A Elisa
%A Tols車n
%A Gustavo
%A Camprub赤
%A Antoni
%A Rubio-Ramos
%A Marco A.
%A Prol-Ledesma
%A Rosa Mar赤a
%J Revista mexicana de ciencias geol車gicas
%D 2008
%I Universidad Nacional Aut車noma de M谷xico
%X in the valle de bravo area, central mexico, two assemblages of cretaceous rocks are exposed. both units present very low grade metamorphism: (1) a meta-sedimentary rock assemblage (ems), and (2) a meta-volcanic rock assemblage (emv). these rocks are part of the ixtapan de la sal - teloloapan volcano-sedimentary metamorphosed mesozoic sequence. the history of deformation of the two assemblages is represented by three sub-horizontal shortening events (d1, d2yd3), that display similar ne-sw orientation, but alternating tectonic transport direction. d1 has a general vergence toward 043 ∼, whereas d2 toward 218∼, and d3 toward 045∼. the three events have been recognized in different localities in guerrero andmichoacan states, and they represent important shortening episodes at regional scale. event d1 exhibits ductile deformation at grain scale, while d2 is brittle-ductile, and d3 presents strictly brittle characteristics. we propose that d1 is the peak metamorphic/deformational event and that d2 and d3 occurred during exhumation of the rocks. during d1and d2, two generations of veins (v1 and v2, respectively) were developed. abundance of the veins has been related directly to the penetrativity of deformation; which suggests that the mobilization of soluble material (mainly by pressure-solution/re-precipitation) was the effective mechanism of deformation at the microscopic scale. this soluble material was deposited in veins in later stages of the deformation event and was more intense during d1. this is demonstrated by the analysis ofmicrostructures in thin section, by outcrop observations and by the comparative-quantitative determination of density of veins through image analysis. in addition to the earlier v1 and v2 veins, late veins (v3) were also identified, and are associated dominantly to normal faults that cut d3 structures. petrography and microthermometric analyses on fluid inclusions were done on quartz and calcite crystals of the three generations of veins in
%K folds
%K deformation
%K veins
%K microthermometry
%K exhumation
%K cretaceous
%K valle de bravo
%K mexico.
%U http://www.scielo.org.mx/scielo.php?script=sci_abstract&pid=S1026-87742008000100004&lng=en&nrm=iso&tlng=en