摘要:

Extant shore platforms are in process of being graded to LWL, just as the whole terrain is being so graded. Thus platforms occur at all possible heights. Other things being equal, lithology determines height. Ecology is important. On macrotidal stormy coasts (e. g. U. K.) the sea is a dominant factor. In hot humid tropics (e. g. Hawaii) intense weathering is a dominant factor (e. g. water layer weathering). Soft rocks graded to LWL have two profiles of equilibrium: (1) Ramp‐type in non‐soluble rocks. (2) Horizontal‐type in soluble rocks. Platforms exist because the sea is more erosive above LWL than below. Endless variation exists in height of tides and waves, so the sea cannot cut at particular levels. ‘Storm wave’ platforms are hard rocks in exposed sites. They are flat because cut by planar swash (not waves) that returns by channels. Criteria for separating tectonic and eustatic factors are

ISSN:0300-9483    

DOI:10.1111/j.1502-3885.1972.tb00141.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Different types of ice‐dammed lakes occur along the Swedish part of the Scandinavian mountain range. Traces of wide open lakes are found mainly in the north and south. In the main part of the area the ice‐dammed basins were more or less filled by dead ice. The ice‐lake distribution indicates that the ice recession in the north and south proceeded towards active centres east of the mountains. In the middle part the corresponding centres were gradually more controlled by the mountain r

ISSN:0300-9483    

DOI:10.1111/j.1502-3885.1972.tb00142.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Recently recognized field evidence clearly indicates that both the Nebraskan and Kansan Glaciations are divisible into stades on the basis of a stratigraphic record of ice‐margin fluctuations. Two Nebraskan stades and three Kansan stades have been identified; it is suggested that others will be found. Recognition of multiple stades requires a thorough review of all Early Pleistocene stratigraphic and paleontologic age assignments applied in the American Midwes

ISSN:0300-9483    

DOI:10.1111/j.1502-3885.1972.tb00143.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

ISSN:0300-9483    

DOI:10.1111/j.1502-3885.1972.tb00144.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY

摘要:

Climatic changes result from variables in planetary orbits which modulate solar energy emission and change seasonal and latitudinal distribution of heat received by the Earth. Small insolation changes are multiplied by the albedo effect of the winter snow fields of the Northern Hemisphere, by ocean‐atmosphere feedbacks, and, probably, by the stratospheric ozone layer. The role of volcanic explosions and other aperiodic phenomena is secondary. The immediate climate response to insolation trends permits astronomic dating of Pleistocene events. A new glacial insolation regime, expected to last 8000 years, began just recently. Mean global temperatures may eventually drop about 1oC in the next hundred years. A refinement of the Milankovitch theory in terms of the lunar orbit and more data on solar periodicities are needed for reliable long range prediction

ISSN:0300-9483    

DOI:10.1111/j.1502-3885.1972.tb00145.x

出版商:Blackwell Publishing Ltd    

年代:1972

数据来源: WILEY