Polyphase white mica growth in low-grade metapelites from La Cébila Metamorphic Complex (Famatinian Belt, Argentina): evidence from microstructural and XRD investigations

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 cébila 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°c) and low-pressure conditions are suggested for m1 event, based in kübler index values ranging from 0.23 to 0.17 a°20, white mica b parameter values between 9.004 and 9.022 á (mean of 9.014 á, n=16) and si contents between 3.13-3.29 a.p.f.u. temperatures of ~180-270°c are estimated for the m2 event, with kübler index values ranging from 0.31 to 0.46 a°20. the m1-d1 event of la cébila could be linked to high-strain heating tectono-metamorphic ordovician regime recorded in others complexes from famatinian foreland region of sierras pampeanas.