|
|
|
|
|
|
|
|
|
Blue rock [volcanic] - (colloquial
| Глоссарий геологических терминов |
Hawaii) the very dense (e.g. 2.75 g/cc), extremely hard and massive, nominally vesicular lava that commonly forms the inner core of an `a`a lava flow. sw
|
|
|
Bolson, английский
(colloquial: western usa.) a term applied to an internally drained (closed) intermontane basin in arid regions where drainages from adjacent mountains converge toward a central depression. bolsons are often tectonically formed depressions. according to peterson, a bolson can include alluvial flat, alluvial plain, beach plain, barrier beach, lake plain, sand sheet, dune, and playa landforms. the piedmont slope above a bolson includes erosional (pediments) and older depositional surfaces (fans) that adjoin the mountain front. a semi-bolson is an externally drained (open) bolson. synonym - intermontane basin. gg and ffp.
Block stream, английский
An accumulation of boulders or angular blocks, with no fine sizes in the upper part, overlying solid or weathered bedrock, colluvium, or alluvium, and lying below a cliff or ledge from which coarse fragments originate. block streams usually occur at the heads of ravines as narrow bodies that are more extensive downslope than along the slope. they may exist on any slope angle, but ordinarily not steeper than 90 percent slope (approx. 40 degrees). compare - block field. gg
|
|
|
|
|
|
|
