Microstructure and fluid flow in the vicinity of basin bounding faults in rifts – The Dombjerg Fault, NE Greenland rift system

Faults commonly form loci for high fluid flux in sedimentary basins, where fluids, rocks and deformation processes frequently interact. Here, we elucidate the interaction of flow, diagenesis near basin-bounding faults basins through a study vicinity (0–3.5 km) Dombjerg Fault NE Greenland rift system. Due to fault-controlled circulation, fault-proximal syn-rift clastics underwent pervasive calcite cementation, whereas uncemented at some distance from fault remained highly porous friable. Correspondingly, two distinct regimes developed accommodate continued deformation: discrete brittle fractures formed cemented rocks, cataclastic bands deposits. We show that low-permeable forming were associated with localized host rock alteration, chemical reduction porosity along bands. In cementation-induced low porosity, created new pathways but subsequently filled calcite. Occasionally, veins comprise multiple generations microcrystalline calcite, likely precipitated rapidly super-saturated fluids injected into fractures. This suggests deposits sealed compartments, overpressure developed. conclude compartmentalized flow may fault-bounded which has wide implications assessments potential carbon storage, hydrocarbon, groundwater, geothermal sites.