| 单词 | chemical fossil |
| 释义 | > as lemmaschemical fossil chemical fossil n. a substance present in a geological deposit which is believed to have originated in the biochemical processes of ancient living organisms; a biomarker; cf. molecular fossil n. at molecular adj. Compounds. ΚΠ 1965 Science 23 Apr. 467/1 Calculations..indicate that these chemical fossils [sc. porphyrins] could not have persisted longer than about 100 years in a lithologic environment subjected to temperatures of 250°C. 1971 Sci. Amer. May 38/3 The chemical analysis of organic material from the Gunflint cherts..reveals the presence of the hydrocarbons pristane and phytane: two ‘chemical fossils’..breakdown products of chlorophyll. 1998 S. C. Morris Crucible of Creation ii. 30 Sponges have recently been identified both as actual fossils, and also as so-called chemical fossils that have been extracted by geochemical techniques from sediments of Ediacaran age. < as lemmas |
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