LOW-GRADE METAMORPHISM OF MESOZOIC AND CENOZOIC VOLCANIC SEQUENCES OFPATAGONIA, CHILE (43-46-DEGREES-S)

Authors
AGUIRRE L CORTES JA MORATA D HERVE F
Citation
L. Aguirre et al., LOW-GRADE METAMORPHISM OF MESOZOIC AND CENOZOIC VOLCANIC SEQUENCES OFPATAGONIA, CHILE (43-46-DEGREES-S), Revista geologica de Chile, 24(2), 1997, pp. 187
Citations number
34
Journal title
Revista geologica de Chile → ACNP
ISSN journal
07160208
Volume
24
Issue
2
Year of publication
1997
Database
ISI
SICI code
0716-0208(1997)24:2<187:LMOMAC>2.0.ZU;2-N
Abstract
Rocks belonging to various units from the Jurassic to the Neogene were studied in the Chilean Patagonian area between 43 and 46 degrees S. A ll these rocks were affected by very low to low grade metamorphism in the zeolite, prehnite-pumpellyite and greenschist facies. Differences in grade are related to the age of the rock sequences with the younges t (Tertiary) metamorphosed in zeolite and the oldest (Jurassic) in gre enschist facies. Temperatures for the metamorphic processes are in the range 120 degrees to 340 degrees C with P below 2 kb. A thermal impri nt of Cretaceous granitoids on the Jurassic rocks exists almost comple tely obliterating an earlier low-grade regional metamorphic pattern.