TY - JOUR
T1 - Geochronology and geothermometry of the Laramide metamorphism in the Cambrian metabasalts from the Cerro Rajón Formation, Caborca region, northwest Mexico
AU - Arturo J, Barrón Díaz
AU - Francisco A, Paz Moreno
AU - Daniel P, Miggins
AU - Alexander, Iriondo
N1 - Publisher Copyright:
© 2019 Elsevier Ltd
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2019/4
Y1 - 2019/4
N2 - Early Cambrian volcanic rocks characterized by pyroclastic and lava flows of basaltic composition form the Cerro Rajón Formation are exposed in the Caborca region, northwest Sonora, Mexico. These rocks underwent greenschist facies metamorphism characterized by a metamorphic paragenesis of actinolite, sphene, chlorite, epidote and calcite with minor interstitial albite. This mineralogical association was characterized by electron microprobe analysis. Metamorphic temperatures were calculated by amphibole-plagioclase geothermometry, which indicates temperatures as high as 548 ± 40 °C. U–Pb geochronology of the pluton that may cause the metamorphism yielded an age of 71.1 ± 0.4 Ma, and an average estimated temperature of 664 ± 40 °C. Preliminary pressures in this intrusive show an average of 3.08 ± 1.5 kbar. Two metamorphic events where identified by 40 Ar/ 39 Ar geochronology. Metabasalt samples from the western part of the study area yielded ages from 55.89 ± 0.6 Ma to 60.26 ± 0.33 Ma, while an age of 81.37 ± 0.81 Ma was obtained from a sample collected in the eastern part. Combined results suggest that Laramide intrusives metamorphosed the Neoproterozoic and Cambrian rocks in the Caborca region.
AB - Early Cambrian volcanic rocks characterized by pyroclastic and lava flows of basaltic composition form the Cerro Rajón Formation are exposed in the Caborca region, northwest Sonora, Mexico. These rocks underwent greenschist facies metamorphism characterized by a metamorphic paragenesis of actinolite, sphene, chlorite, epidote and calcite with minor interstitial albite. This mineralogical association was characterized by electron microprobe analysis. Metamorphic temperatures were calculated by amphibole-plagioclase geothermometry, which indicates temperatures as high as 548 ± 40 °C. U–Pb geochronology of the pluton that may cause the metamorphism yielded an age of 71.1 ± 0.4 Ma, and an average estimated temperature of 664 ± 40 °C. Preliminary pressures in this intrusive show an average of 3.08 ± 1.5 kbar. Two metamorphic events where identified by 40 Ar/ 39 Ar geochronology. Metabasalt samples from the western part of the study area yielded ages from 55.89 ± 0.6 Ma to 60.26 ± 0.33 Ma, while an age of 81.37 ± 0.81 Ma was obtained from a sample collected in the eastern part. Combined results suggest that Laramide intrusives metamorphosed the Neoproterozoic and Cambrian rocks in the Caborca region.
UR - http://www.scopus.com/inward/record.url?scp=85060715458&partnerID=8YFLogxK
U2 - 10.1016/j.jsames.2019.01.005
DO - 10.1016/j.jsames.2019.01.005
M3 - Artículo
AN - SCOPUS:85060715458
VL - 91
SP - 47
EP - 56
JO - Journal of South American Earth Sciences
JF - Journal of South American Earth Sciences
SN - 0895-9811
ER -