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Short Communication |
1 University of Aberdeen, Department of Geology and Petroleum Geology, King's College, Aberdeen AB24 3UE, UK (e-mail: m.vigorito{at}abdn.ac.uk)
2 3DLab, School of Earth, Ocean and Planetary Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3YE, UK
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.