The sliding bed facies in esker sands and gravels: a criterion for full‐pipe (tunnel) flow?

摘要: The Guelph esker (Ontario, Canada) consists of a sinuous, steep-sided and segmented ridge which comprises poorly sorted, matrix-supported sands gravels. These gravels were probably deposited during the sliding bed stage has been observed by others in closed-conduit hydraulic experiments. poor sorting resulted from high concentration bed-material load lower part subglacial tunnel, being restricted to that produced particle collisions. Inclusive graphic standard deviation is characteristically large for gravels, indicating virtually all sizes available transport. overall grain size distribution shows characteristic undulatory shape on arithmetic probability paper, mostly because selective removal pebble gravel granule sizes. This sorted fades believed be diagnostic transport tunnel flowing full water, may used identify conditions other eskers. Deltaic occur downcurrent contain greater diversity structures; climbing-ripple cross-laminae, parallel laminae massive structure, large-scale foresees at end tunnel. deltaic grade distally into outwash