Regional-scale subsurface sand remobilization: geometry and architecture

An architectural hierarchy of clastic sills is recognized in the Panoche Giant Injection Complex in which staggered, stepped with erosive top surfaces, and multi-layered geometries occur in that stratigraphic order upward. Genetic relationships between parent depositional sand bodies, the sand injections, a zone of hydraulic fracture and a palaeo sea floor are seen at a scale previously observed only by using seismic data. Sills and randomly oriented dykes intrude into a hydraulically fractured shale unit above and below which dykes predominate. Erosive surfaces (scallops) are identified on sills that, along with smaller erosional features, record low-viscosity turbulent flow during sand injection. Sand extrusions occur where dykes reach the palaeo sea floor