Burial Diagenesis of Magnetic Minerals: New Insights from the Grès d’Annot Transect (SE France)

Minerals

Myriam Kars¹  Charles Aubourg¹  Pierre Labaume²  Thelma S. Berquó³ 

[1] Laboratoire des Fluides Complexes et leurs Réservoirs, Université de Pau et des Pays de l’Adour, UMR 5150 CNRS TOTAL, Avenue de l’Université, 64013 Pau cedex, France; E-Mail:;Géosciences Montpellier, Université de Montpellier 2, UMR 5243 CNRS, Place E. Bataillon, 34095 Montpellier cedex 5, France; E-Mails:;Physics Department, Concordia College, 901 8th St. S., Moorhead, MN 56562, USA; E-Mail:

关键词: Grès d’Annot basin;    burial diagenesis;    magnetite;    pyrrhotite;    paleotemperature;   

DOI  :  10.3390/min4030667

来源: mdpi

【 摘 要 】

The diagenetic evolution of the magnetic minerals during burial in sedimentary basins has been recently proposed. In this study, we provide new data from the Grès d’Annot basin, SE France. We analyze fine-grained clastic rocks that suffered a burial temperature from ~60 to >250 °C, i.e., covering oil and gas windows. Low temperature magnetic measurements (10–300 K), coupled with vitrinite reflectance data, aim at defining the magnetic mineral evolution through the burial history. Magnetite is documented throughout the entire studied transect. Goethite, probably occurring as nanoparticles, is found for a burial temperature <80 °C. Micron-sized pyrrhotite is highlighted for a burial temperature >200 °C below the Alpine nappes and the Penninic Front. A model of the evolution of the magnetic assemblage from 60 to >250 °C is proposed for clastic rocks, containing iron sulfides (pyrite) and organic matter. This work provides the grounds for a better understanding of the magnetic properties of petroleum plays.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.