Orogenic style, sea level, sr isotopes and a brief history of the earth for the last 600 million years

Sengor A.

RUSSIAN GEOLOGY AND GEOPHYSICS, vol.47, no.1, pp.21-31, 2006 (Journal Indexed in SCI) identifier

  • Publication Type: Article / Article
  • Volume: 47 Issue: 1
  • Publication Date: 2006
  • Page Numbers: pp.21-31


Turkic-type orogeny, a kind of collisional orogeny involving the growth and eventual apposition of very large subduction-accretion prisms, commonly but not necessarily with significant net crustal growth, leads to rising sea level, low (87)Sr/(86)Sr ratio in seawater and an equable, generally ice-cap free "greenhouse" world climate during its subductive growth phase. When its growth is arrested by collision, it leads to lower sea level, high (87)Sr/(86)Sr ratio in seawater and a harsh "icehouse" world climate commonly with recurrent ice ages. Greenhouse/icehouse environments thus generally correspond to the subductive growth and collisional destruction phases of Turkic-type accretionary complexes. At any one time in the Earth's history few Turkic-type orogenic systems existed on the Earth; their subductive growth was slow to span long time intervals, and, by contrast, their collisional destruction has been much faster. If the model presented in this paper is correct, much of the Earth's physical geography may have been influenced by Turkic- type orogeny at least during the Phanerozoic. This seems to hold true also for the later Proterozoic, although data precision does not allow as good inferences as one can draw for the Phanerozoic world.