Are the “magnetite lava flows” of El Laco (Chile) magmatic? Comparison of trace elements in magnetite with other magmatic Fe-oxide deposits (original) (raw)

2012

Abstract

Magnetite forms under a wide variety of conditions, crystallizing at high temperature from silicate magmas or precipitating at low temperature from hydrothermal fluids or seawater. Trace element content of magnetite may reflect the differences in these conditions. Therefore as part of a larger project examining the trace element content of magnetite, by laser ablation ICP-MS, we have characterized magnetite in magmatic massive Fe-oxide deposits (magnetite-ilmenite, ± apatite) from layered intrusions (Bushveld and Sept Iles Complexes) and a massif anorthosite (Lac St. Jean) in order to study how magmatic processes affect the trace element compositions. We have also collected trace element data from the enigmatic “magnetite lava flows” from El Laco, Chile, in order to consider whether these magnetites are indeed of igneous origin. Magnetite from the layered intrusions record the evolution of the fractionating silicate liquid (Fig. 1a), with those found lower in the sequence (more prim...

Sarah Dare hasn't uploaded this paper.

Let Sarah know you want this paper to be uploaded.

Ask for this paper to be uploaded.