Trace-element and Sr–Nd isotopic geochemistry of the PGE-bearing Xinjie layered intrusion in SW China

2004 ◽  
Vol 203 (3-4) ◽  
pp. 237-252 ◽  
Author(s):  
Hong Zhong ◽  
Yong Yao ◽  
Stephen A. Prevec ◽  
Allan H. Wilson ◽  
Morris J. Viljoen ◽  
...  
2003 ◽  
Vol 45 (4) ◽  
pp. 371-382 ◽  
Author(s):  
H. Zhong ◽  
Y. Yao ◽  
S. F. Hu ◽  
X. H. Zhou ◽  
B. G. Liu ◽  
...  

Author(s):  
R. R. Harding

AbstractThe structures and mineralogy of the Tertiary ultrabasic and basic intrusions are described. The ultrabasic rocks are thought to be remnants of a layered intrusion which once extended from Hirta to Boreray, and which probably formed by crystal accumulation. The eucrites may represent higher levels of this intrusion. A 350 feet-thick, fine-grained margin is described from the East Glen Bay Gabbro. The metamorphism of the ultrabasic and eucritic rocks, and the formation of the Glacan Mor Complex, probably occurred in a basic environment, before intrusion of the first acid rocks on St. Kilda. Five major-element and twenty-two trace-element analyses are presented.


1975 ◽  
Vol 12 (3) ◽  
pp. 361-370 ◽  
Author(s):  
Jackson M. Barton Jr. ◽  
Erika S. Barton

The Snyder breccia is composed of angular to subrounded xenoliths of migmatites and amphibolites in a very fine grained matrix. It is apparently intrusive into the metasediments of the Snyder Group exposed at Snyder Bay, Labrador. The Snyder Group unconformably overlies a migmatitic and amphibolitic basement complex and is intruded by the Kiglapait layered intrusion. K–Ar ages indicate that the basement complex is Archean in age (> 2600 m.y. old) and that the Kiglapait layered intrusion was emplaced prior to 1280 m.y. ago. Major and trace element analyses of the matrix of the Snyder breccia indicate that while it was originally of tonalitic composition, later it locally underwent alteration characterized by loss of sodium and strontium and gain of potassium, rubidium and barium. Rb–Sr isotopic analyses show that this alteration occurred about 1842 m.y. ago, most probably contemporaneously with emplacement of the breccia. The Snyder Group thus was deposited sometime between 2600 and 1842 m.y. ago and may be correlative with other Aphebian successions preserved on the North Atlantic Archean craton.


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