Dropstones are isolated fragments of rock found within finer-grained water-deposited sedimentary rocks or pyroclastic beds. They range in size from small pebbles to boulders.

2023年1月3日 · Dropstones indicate that a rock was, by some agency, relocated to a still, low-energy environment. Once a stone is transported to a body of water and then released into it, …

Several specialized programs comprise the UGS: Data Management, Energy & Minerals, Geologic Hazards, Geologic Information & Outreach, Geologic Mapping, Groundwater & …

1996年5月1日 · Dropstones are the product of two distinct entrainment and transport mechanisms: by a rafting agent, or as a projectile. Four main processes of transport and …

1996年5月1日 · Dropstones are the product of two distinct entrainment and transport mechanisms: by a rafting agent, or as a projectile. Four main processes of transport and …

Varved sediments may contain dropstones, which are fragments of rock that have dropped from an overlying floating ice sheet and that have sunk into and depressed the layers beneath …

2018年3月23日 · Fieldwork in now-arid Namibia has uncovered dropstones—large chunks of rock frozen to the underside of icebergs that are dropped into the ocean as the ice moves and …

2008年10月27日 · The very large rock - called a dropstone - that has come from the melting glacier is substantially different in size than the material on the seafloor. Because of the …

Lake Bonneville was the largest Late Pleistocene paleolake in the Great Basin of western North America. It was a pluvial lake that formed in response to an increase in precipitation and a …

1997年6月1日 · Laminated sand- and siltstones containing dropstones are abundant in the lower Unit and very rare in the upper one. Deposits of subaqueous mass flows are present in both …