%0 Journal Article
%T Polyphase white mica growth in low-grade metapelites from La C¨¦bila Metamorphic Complex (Famatinian Belt, Argentina): evidence from microstructural and XRD investigations
%A Verdecchia
%A Sebasti¨¢n O
%A Collo
%A Gilda
%A Baldo
%A Edgardo G
%J Andean geology
%D 2011
%I Scientific Electronic Library Online
%X two tectono-thermal metamorphic events, m1-d1 (s1, with associated white mica and chlorite: wm1-chl1) and m2-d2 (s2, with development of wm2-chl2), are established from polyphase white mica growth for low-grade units from the ordovician metasedimentary successions of la c¨¦bila metamorphic complex in the famatinian belt (western-central argentina). the thermobarometric characterization of the m1 main event was carried out by means of clay-mineral analysis and crystallo-chemical parameter measurements. epizonal (temperatures between 300 and 400¡ãc) and low-pressure conditions are suggested for m1 event, based in k¨¹bler index values ranging from 0.23 to 0.17 a¡ã20, white mica b parameter values between 9.004 and 9.022 ¨¢ (mean of 9.014 ¨¢, n=16) and si contents between 3.13-3.29 a.p.f.u. temperatures of ~180-270¡ãc are estimated for the m2 event, with k¨¹bler index values ranging from 0.31 to 0.46 a¡ã20. the m1-d1 event of la c¨¦bila could be linked to high-strain heating tectono-metamorphic ordovician regime recorded in others complexes from famatinian foreland region of sierras pampeanas.
%K sierras pampeanas
%K low pressure
%K k¨¹bler index
%K white mica b parameter.
%U http://www.scielo.cl/scielo.php?script=sci_abstract&pid=S0718-71062011000200002&lng=en&nrm=iso&tlng=en