英和和英

名詞

geochronometer (複数形 geochronometers)

1. (geology, geochronology) Any of several techniques used to measure the age of rock, especially any technique of radiometric dating, the measuring of the relative abundance of particular radioactive or radiogenic isotopes in order to evaluate the progress of radioactive decay.
   • 2009, P. J. Hamilton, A review of radiometric dating techniques for clay mineral cements in sandstones, Richard Worden, Sadoon Morad (editors), Clay Mineral Cements in Sandstones, Wiley, page 273,

     Application of the ${\displaystyle {\ce {K-Ca}}}$ geochronometer therefore is best suited to minerals with high ${\displaystyle {\ce {K/Ca}}}$ ratios (Marshall & DePaolo, 1982) and ${\displaystyle {\ce {K}}}$-bearing clay materials might appear to be amenable to its use.

   • 2019, Marek Smoluch, Giuseppe Grasso, Piotr Suder, Jerzy Silberring (editors), Mass Spectrometry, Wiley, 2nd Edition, page 327,

     Other geochronometers like ${\displaystyle {\ce {^{87}Rb-\!^{87}Sr}}}$, ${\displaystyle {\ce {^{147}Sm-\!^{143}Nd}}}$, or ${\displaystyle {\ce {^{187}Re-\!^{187}Os}}}$ are also successfully applied to dating ore deposits and magmatic, metamorphic, or sedimentary processes.

2. Any of several crystalline minerals that remain stable over geologic time and that when formed contained radioisotopes whose abundance relative to their decay products can be measured to calculate the age of the crystal (かつ thus that of the surrounding rock).
   • 1997, G. S. Odin, A. Deino, M. Cosca, M. A. Laurenzi, A. Montanari, F1: Miocene geochronology, A. Montanari, R. Coccioni, G. S. Odin (editors), Miocene Stratigraphy, Elsevier, page 584,

     ${\displaystyle {\ce {K}}}$-bearing minerals such as biotite, sanidine, plagioclase, and hornblende are geochronometers representative of the time of their crystallization once they were erupted from a volcano, and then transported into marine sedimentary basins.

関連する語

• chronometer
• geochronometry