Temperature estimates obtained with various biotite-garnet thermometers are inconsistent in granulite facies rocks. Although the inconsistency lies partly in the lack of definition of equilibrium criteria, it still remains after rigorous selection of analyzed mineral pairs (isolated biotite and garnet cores for peak equilibrium conditions) and originate from minor element effects in garnet and ...

The Conlara Metamorphic Complex, the easternmost complex of Sierra de San Luis, is a key unit to understand relationship between late Proterozoic-Early Cambrian Pampean and Upper Cambrian-Middle Ordovician Famatinian orogenies Eastern Sierras Pampeanas. Complex extends east foothills Comechingones west up Río Guzmán shear zone. main rock types CMC are metaclastic metaigneous rocks that intruded...

introduction the area studied is located north of azna (lorestan province) in a small portion of the sanandaj – sirjan structural zone (mohajjel et al., 2003).this area is part of the zagros orogenic belt, formed by the opening and closure of neotethyan ocean. from ne to sw, it consists of three parallel tectonic regions: the orumieh-dokhtar magmatic belt, the sanandaj-sirjan structural zone an...

The Massif Central, like the southern part of the Massif Armoricain, belongs to the North Gondwana margin. The Massif Central consists of a stack of nappes resulting of six main tectonicmetamorphic events. The first one, D0, is coeval with an Early Late Silurian (ca 415 Ma) highpressure (or ultra high-pressure) metamorphism for which the associated structures are poorly documented. The Early De...

Polygenetic monazite grains in diverse Precambrian crystalline rocks from the Black Hills, South Dakota, have been analyzed in situ by ion and electron microprobe methods (SHRIMP and EMP), to evaluate the accuracy and precision of EMP ages determined using a new analytical protocol that incorporates improved background acquisition and interference corrections. Parallel evaluations were conducte...