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Allogroup
Словарь стратиграфических терминов |
An allostratigraphic unit next in rank above an alloformation (see allostratigraphic unit). 107
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Alloformation, английский
The fundamental allostratigraphic unit (see allostratigraphic unit).
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Allomember, английский
An allostratigraphic unit next in rank below an alloformation (see allostratigraphic unit).
Isotopic age, английский
An age expressed in years or millions of years calculated from the quantitative determination of the content of the parent and daughter nuclides during the decay of radioactive elements. the abbreviations ka for thousand (103), ma for million (106), and ga for billion (milliard or thousand million, 109) years are now generally used to express the length of time before the present (years ago), not the duration of a past geological time interval. 124 k
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