Hydrocarbons in silica: PVTX properties of fluids and the genesis of diamond quartz from Caravia-Berbes Fluorite district (Asturias, Spain)

Levresse, Gilles ✉; Tritlla, Jordi; Ramos Rosique, Aldo; Cardellach, Esteve; Rollion-Bard, Claire; Pironon, Jacques; Jimenez Sandoval, Sergio

Angol nyelvű Tudományos Szakcikk (Folyóiratcikk)
  • SJR Scopus - Economic Geology: Q1
    The fluid history of "diamond" quartz crystals from Caravia-Berbes Fluorite district is intimately related with episodes of maturation and migration of hydrocarbons within the Asturian basin, probably linked to the structural activation of a Mesozoic rift system. These "diamond" quartz record the migration of hydrothermal silica-rich brines and associated hydrocarbons that recorded a temperature increase (outlined by fluid inclusion studies) from similar to 90 to similar to 140 degrees C. This gradient is also recorded by a change in the organic matter species trapped in quartz, from bitumen located in the inner quartz growth zones to liquid hydrocarbons trapped within the outer quartz overgrowths. Secondary ion mass spectrometer (SIMS) oxygen isotope microanalyses allowed to differentiate two delta O-18(H2O) values corresponding to the oil-dominated zone (core) and the water-dominated zone (outer growth zone). The heavier delta O-18(H2O) values in the water-dominated zone do not only record a higher temperature of formation, but also an increase in the delta O-18(H2O) of the parental fluid. Isotopic compositions of diamond quartz suggest a heterogeneous source of surficial fluids and formation-waters expelled from clays tones.Within the basin history, the diamond quartz precipitation took place during early Jurassic to Eocene subsidence periods. Pressure Temperature and composition (PTX) and delta O-18(H2O) characteristics point out a probable relationship with Albian diagenetic events reported in Cantabrian and north Pyrenean basins.
    Hivatkozás stílusok: IEEEACMAPAChicagoHarvardCSLMásolásNyomtatás
    2020-09-18 13:21