Сборник упражнений по грамматике английского языка. Стрелкова М.С. - 27 стр.

oped.
      28) Several of the faults were responsible for the location of Caledonian
granites, which appear to have made their way up to higher levels in the crust
along these lines of weakness, which opened up spaces during fault movement.
      29) The mechanism that finally triggered the most recent ice age appears to
have been the change in ocean-current circulation resulting from the collision
between South and North America, which was completed by 2 million years
ago.
      30) Although layered komatiite flows with spinifex-textured upper parts
and olivine enriched lower parts are commonly thought to provide firm evidence
of magmatic differentiation by olivine settling, there are, however the reasons
for some other suggestion.
      31) Oil is believed to be the product of the decomposition of organic mat-
ter, both plant and animal.
      32) Other factors such as duration of emplacement, the total volume of
granitoid masses, the silica content and the activity of the volcanoes seems to
decrease from older to younger complex.
      33) The Bait Hill volcano is believed to have originated as a mildly alkaline
seamount which was accreted from the subducting Iapetus plate.
      34) As adiabatic fractional melting is believed to closely approximate to
adiabatic decompression melting of the mantle, this is considered to provide
more accurate results for the generation of the Guddapah lavas.
      35) The modal contents of constituent minerals and their melting propor-
tions are taken from James (1992) and are assumed to closely approximate to
peridotite KLB-1.
      36) The initial concentrations and partition coefficients for Nb are used for
melting calculations and assumed to be similar to those of primitive mantle
melts.
      37) Some trace element features appear to be associated with particular iso-
tope signature and there is a long-standing debate over the extent to which en-
riched components reflect intra-mantle processes.
      38) Oil contains nitrogen and certain compounds (porphyrins) that scien-
tists believe can only originate in living matter.
      39) NGU also considers the prospects to be good for export of natural
stones.
      40) Negative charge greater than average may only point the rejuvenation


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