thumbnail

Some Nd and Sr isotopic systematics for the REE-enriched deposit at Bayan Obo, China

Chemical Geology

By:
, , ,
DOI: 10.1016/0009-2541(91)90098-C

Links

Abstract

Sm/1bNd and Rb/1bSr isotopic systematics have been determined for rare-earth element (REE) rich samples of carbonate, iron ore, and silicate types from the world's largest known REE deposit at Bayan Obo, China. The results yielded neither Rb/1bSr nor Sm/1bNd isochrons within analytical error. Isochronous relationships may have been disturbed in part by younger events. Modes in isotopic composition suggest two Sr reservoirs; the low 87Sr 86Sr ratios of 0.703 and 0.704 measured for two carbonates may be of mantle origin. The Sm/1bNd data delineate a trend at ??? 1 Ga; this trend might represent a disturbed fractionation event or mixing of Nd reservoirs. The REE ores could not have formed in a single fractionation event during the igneous activity at 260 Ma. Model ages suggest that the ore REE were isolated from mantle sources between ??? 1.7 and ??? 1.3 Ga. This time period hosts major anorogenic igneous activity, including anorthosites, and a number of other unusual REE iron ores. ?? 1991.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Some Nd and Sr isotopic systematics for the REE-enriched deposit at Bayan Obo, China
Series title:
Chemical Geology
DOI:
10.1016/0009-2541(91)90098-C
Volume
90
Issue:
3-4
Year Published:
1991
Language:
English
Publisher:
Elsevier
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
177
Last page:
188
Number of Pages:
12