Titaniferous Clinohumite from Gardiner Plateau Complex, East Greenland

T. F. D. Nielsen and O. Johnsen
Institute of Petrology and Geological Museum, University of Copenhagen, Øster Voldgade 5–7, DK-1350 Copenhagen K, Denmark

Summary: Titaniferous clinohumite occurs as a major constituent in the centres of late magmatic veins in the Tertiary ultramafic, strongly alkaline Gardiner Plateau Complex in East Greenland (69° N. and 32° W.). The complex is briefly described and an electron microprobe analysis of titaniferous clinohumite is presented. This gives the following: 38·44% SiO2, 2·99% TiO2, 4·87% FeO, 51·89% MgO, 1·3% F, H2Ocalc 1·50%, and total 100·44%. Optical data, density, and unit cell dimensions are also presented. Of magmatic occurrences, titaniferous clinohumite has otherwise only been reported in certain kimberlites and carbonatites.

Mineralogical Magazine; March 1978 v. 42; no. 321; p. 99-101; DOI: 10.1180/minmag.1978.042.321.14
© 1978, The Mineralogical Society
Mineralogical Society (www.minersoc.org)