Evolution of diagenetic conditions and burial history in Buntsandstein Gp. fractured sandstones (Upper Rhine Graben) from in-situ δ18O of quartz and 40Ar/39Ar geochronology of K-feldspar overgrowths

Abstract In-situ δ 18 O measured in the quartz overgrowths help identify temperature and fluid origin variations responsible for cementation of pore network (matrix fracture) Buntsandstein Gp. sandstone reservoirs within Upper Rhine Graben. The record two types evolution O: 1) a monotonous decrease overgrowth interpreted as linked to an increasing burial 2) random fluctuations, pointing out injection allochthonous fluids faulted areas, on processes (both intergranular fracture planes). Fluids causing are either autochthonous buffered from clay illitisation; or meteoric with below − 5%. These thermal disequilibrium host sandstone. signal samples calculated curves testing hypothetic compared T–t during burial. This modelling proposes initiation Jurassic is validated by in-situ 40 Ar/ 39 Ar dating results obtained feldspar predating overgrowths. A similar diagenetic history recorded graben shoulders buried parts basin. Here, beginning predates structuration blocks basin before Cenozoic opening.