ISSN:
0016-7835
Keywords:
Key words Northern Chile
;
Jurassic magmatic arc
;
Mafic granulite Sm
;
Nd isotope chemistry and ages
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
Notes:
Abstract We investigated the Sm–Nd systematics of mafic granulite and undeformed layered gabbro, which form a midcrustal section of the Jurassic magmatic belt in the North Chilean Coast Range, south of Antofagasta. Mineral isochrons indicate ages between ca. 171 and 150 Ma for the granulite and an age of ca. 161 Ma for the gabbro. These ages are interpreted as closure time of the Sm–Nd system in the area. The age of metamorphism is Late-Jurassic. The minimum intrusion age of the protolith of the granulite is likely Early Jurassic (ca. 200 Ma), but an exact intrusion age could not be derived from the data. The intrusion age of the gabbro is ca. 185 Ma. Granulite generated from mantle-derived gabbroic magmas has ɛNd200 between 6.28 and 7.05 and the gabbro that intruded the granulite has ɛNd185 between 5.89 and 6.09.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s005310050175
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