Significance of REE study for origin of sparry magnesite in Orhaneli Region, Turkey

Citation
F. Suner et al., Significance of REE study for origin of sparry magnesite in Orhaneli Region, Turkey, J GEOL S IN, 58(3), 2001, pp. 231-237
Citations number
14
Categorie Soggetti
Earth Sciences
Journal title
JOURNAL OF THE GEOLOGICAL SOCIETY OF INDIA
ISSN journal
00167622 → ACNP
Volume
58
Issue
3
Year of publication
2001
Pages
231 - 237
Database
ISI
SICI code
0016-7622(200109)58:3<231:SORSFO>2.0.ZU;2-D
Abstract
Pattern of REE distribution in various types of magnesite ore occurring wit hin the Late Cretaceous ultramafics in Orhaneli Region (Western Anatolia) w ere studied to interpret their genetic significance. The samples were class ified into three different groups viz. massive, lentiform and pignolite or stockwork. Individual groups exhibit distinctly different REE distribution pattern with variable Eu, Ce and Yb anomalies. Three types of REE distribut ion patterns are recognizable with the following characteristics: (1) high LREE/HREE ratios without having Cc and Eu anomalies, (2) similar LREE and H REE abundance with uncertain positive and negative Eu and Ce anomalies, and (3) low REE abundance with markedly positive Eu, negative Ce and slightly negative Yb anomalies. It is postulated that the redox conditions in the pr imary mineral formation system was subjected to change and as a result, sub sequent mobilization followed by recrystallization took place in the format ion of primary magnesite minerals. Although a low temperature environment i s indicated for magnesite formation, it is possible that REE-poor solutions derived from the fluid-rock interaction had caused mobilization and later recrystallization of magnesite ore.