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  • 館藏編號:NTUG010-T600007
  • 題名:準平原的成因
  • 作者:馬廷英
  • 藏品形式:稿本
  • 尺寸:180X250(mm)
  • 作成日期:1966
  • 簡述:Origin of Peneplains, P.6
  • 內容:

    "Origin of Peneplains, P.6
    the Great Coastal Plain region including the Mississippi valley and uplands there around, the surface of the subdued topography of mature stage, from the lower margin of the penultimate peneplain to the coastal plains with senile physiographical features, formed during marine regression due to rotational uplift of fragmented upper mantle layers and crust from the end of the penultimate adjusting uplift of the mantle until the last mantle displacement, was suddenly submerged by the last epeirogenic subsidence of the mantle in the North Atlantic region for receiving accumulation of glacial sediments from different floating ice-sheets or icebergs. All the drifts left by different ice-sheets freed from glaciers of different regions by the last epeirogenic subsidence of the mantle in the North Atlantic region accumulated on the suddenly submerged erosion surface with various sediments from silt to conglomerate including peat beds and fossil forests89,70 at different elevations corresponding to the strandline moving with rotational uplift of fragmented upper mantle layers and crust before the last mantle displacement and were later covered by sediments deposited during the last adjusting uplift of the mantle or redeposited with them so that they have been regarded as of four Quaternary glacial stages with three necessary interglacial stages intercalated. The fossil forests which have been regarded as of different interglacial stages and a great amount of remains of elephants of many species reported from
    many sites on the North Atlantic continental shelf of North America71, are all the land life mass-killed by the sudden marine transgression due to the last epeirogenic
    subsidence of the mantle occurring 65,000 B.P. Much greater amount of land animals were mass-killed by the sudden marine transgression due to the last epeirogenic subsidence of the mantle in Australia in antipodal position to the North Atlantic region, and their remains have been found (a) in old flood-plains and alluvial deposits; (b) in lake- and spring-deposits; (c) in caves; and (d) in beds of volcanic ash over the continent.
    Due to the repeated double marine abrasions caused by the sudden epeirogenic subsidences followed by adjusting uplifts with the last four mantle displacements, the bottom of rivers graded into very slow gradients extend from the coast across the Great Coastal Plain up a great distance into the gorges of the high mountain region wherefrom they originated. Therefore, even a great river as the Mississippi of great volume of flow has only power to transport a small portion of its fine sediments to the river mouth for accumulation as deltaic sediments but leaves most part of the fine sediments at different elevations as alluvial in its drainage basin. The great amount of unconsolidated sediments below sea level off the Atlantic coast of North America resulted from the repeated marine erosions during adjusting uplifts following sudden epeirogenic subsidences with the last four mantle displacements, and the distribution of thick unconsolidated sediments from the continental shelf to a great depth down the continental slope is due to landslidings caused by the intermittent tectonic movements during the adjusting uplifts following sudden epeirogenic subsidences in the North Atlantic region with the last four mantle displacements as well as due to gravity acting on sediments accumulated on the strandline moving with"