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Organic Matter Optical Analysis and Clay Mineralogy to Unravel the Tectonic/Sedimentary Burial in the Laga Basin, Italy
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 70th EAGE Conference and Exhibition incorporating SPE EUROPEC 2008, Jun 2008, cp-40-00380
- ISBN: 978-90-73781-53-5
Abstract
Vitrinite reflectance data and clay mineral assemblages were used to investigate levels of diagenesis from the Messinian Laga Basin (Central Apennines) developed at the footwall of the Sibillini Mts. and the Gran Sasso Massif. Data derive from stratigraphic units forming the siliciclastic basin fill up to Middle Messinian gypsum-arenites and its pre-orogenic substratum. Highest Ro% values and percentages of illite layers in I/S are found in the basin depocentre and at the footwall of the carbonate thrust sheets. Lower Ro% values and percentage of illite layers in I/S characterize less subsided sectors. I/S records the maximum paleo-temperature the Laga Fm. experienced related to its burial history whereas KI data suggest higher temperatures related to detrital K-micas inherited from the uplift of the Alpine-Apennines chain. A calculation of paleo-temperatures from selected data of organic and inorganic parameters is proposed and compared with recent stratigraphic and structural data. This allowed proposing that the Laga basin fill never experienced temperatures >100-110°C, due to variable sedimentary loading, while localised anomalous heating is due to the effect of the tectonic emplacement and subsequent local erosion of the Sibillini and Gran Sasso thrust sheets.