Diamond growth from organic compounds in hydrous fluids deep within the Earth.

ABSTRACT: At subduction zones, most diamonds form by carbon saturation in hydrous fluids released from lithospheric plates on equilibration with mantle rocks. Although organic molecules are predicted among dissolved species which are the source for carbon in diamonds, their occurrence is not demonstrated in nature, and the physical model for crustal diamond formation is debated. Here, using Raman microspectroscopy, I determine the structure of carbon-based phases inside fluid inclusions in diamond-bearing rocks from the Alps. The results provide direct evidence that diamond surfaces are coated by sp²-, and sp³-bonded amorphous carbon and functional groups of carboxylic acids (e.g., carboxyl, carboxylate, methyl, and methylene), indicating the geosynthesis of organic compounds i

SUBMITTER: Frezzotti ML 

PROVIDER: S-EPMC6821813 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature