|
|||||
|
|
The Zircon-Bearing Chromitites of the Phlogopite Peridotite of Finero (Ivrea Zone, Southern Alps): Evidence and Geochronology of a Metasomatized Mantle Slab |
|
| Authors: | GRIECO G; FERRARIO A; VON QUADT A; KOEPPEL V; MATHEZ E A |
| Institution: | 1DIPARTIMENTO DI SCIENZE DELLA TERRA, UNIVERSITÀ DEGLI STUDI DI MILANO, VIA BOTTICELLI 23, 20133, MILANO, ITALY 2ETH ZENTRUM, 8092, ZÜRICH, SWITZERLAND 3DEPARTMENT OF EARTH AND PLANETARY SCIENCES, AMERICAN MUSEUM OF NATURAL HISTORY, NEW YORK, NY 10024, USA |
| Abstract: | The phlogopite peridotite unit of the Finero Complex is a restiticharzburgite that records two metasomatic events. The first eventis related to the intrusion of basaltic magma, which reactedwith the pyroxene of the host harzburgite to produce chromititepods with dunite haloes. It also produced secondary clinopyroxeneand amphibole in the harzburgite and enriched harzburgite inNa and the light rare earth elements. The second metasomaticevent is related to the later intrusion of clinopyroxeniticdykes. During this event, water-rich vapour penetrated the harzburgitealong fractures and reacted with it to form phlogopite, thusenriching the rock in K. Chromitites host zircons that yieldan age for the first metasomatic event of 207·9 + 1·7/-1·3Ma, during which time extensional tectonics prevailed in theSouthern Alps. KEY WORDS: metasomatism; chromitite; zircon; geochronology; Finero |
| Keywords: | |
| 本文献已被 Oxford 等数据库收录！ | |