TY - JOUR

T1 - The Earliest Generation of Diamond: The First Find of a Diamond Inclusion in Kimberlitic Olivine

AU - Pokhilenko, Lyudmila

AU - Pokhilenko, Nikolay

AU - Malkovets, Vladimir

AU - Alifirova, Taisia

N1 - L. Pokhilenko is grateful for the support of the Russian Science Foundation (project number 21-17-00082). The Re-Os isotopic studies were investigated by V.M. with support from the Russian Science Foundation (project number 22-27-00724). N.P. acknowledges the support of the Russian Foundation for Basic Research (grant number 20-05-00662).

PY - 2023/1

Y1 - 2023/1

N2 - Today, it is known that the majority of diamonds are crystallized mostly from a metasomatic agent close in the main characteristics to carbonatite melts acting upon mantle rocks, and therefore, diamonds are located in the interstitial space of these rocks. So far, diamond has never been found included in other kimberlitic or xenolithic minerals. We have found a diamond inclusion inside the kimberlitic olivine grain, which is the first find of its kind. The diamond crystal is to have been captured by the growing olivine at quite high temperatures (more than 1400 °C) early in the history of the cratonic lithospheric mantle formation. The event had taken place long before the depleted peridotite cooled down to the temperature of the Middle Archean cratonic geotherm corresponding to the diamond stability field at depths where carbonatite melts can react with depleted peridotite, making it a diamond-bearing rock. On the one hand, this find provides evidence that diamonds can crystallize from the high-temperature silicate melt with some carbonate component. On the other hand, the diamond was found coexisting with a sulfide inclusion in the same olivine, i.e., crystallization from a sulfide melt may be another way of diamond formation.

AB - Today, it is known that the majority of diamonds are crystallized mostly from a metasomatic agent close in the main characteristics to carbonatite melts acting upon mantle rocks, and therefore, diamonds are located in the interstitial space of these rocks. So far, diamond has never been found included in other kimberlitic or xenolithic minerals. We have found a diamond inclusion inside the kimberlitic olivine grain, which is the first find of its kind. The diamond crystal is to have been captured by the growing olivine at quite high temperatures (more than 1400 °C) early in the history of the cratonic lithospheric mantle formation. The event had taken place long before the depleted peridotite cooled down to the temperature of the Middle Archean cratonic geotherm corresponding to the diamond stability field at depths where carbonatite melts can react with depleted peridotite, making it a diamond-bearing rock. On the one hand, this find provides evidence that diamonds can crystallize from the high-temperature silicate melt with some carbonate component. On the other hand, the diamond was found coexisting with a sulfide inclusion in the same olivine, i.e., crystallization from a sulfide melt may be another way of diamond formation.

KW - Middle Archean cratonic geotherm

KW - diamond

KW - diamond-forming media

KW - lithospheric mantle

KW - olivine

KW - sulfide

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85146712881&origin=inward&txGid=8df59a0e52846508595486599ce5cbb9

UR - https://www.mendeley.com/catalogue/47dccf03-d79f-356e-8892-ef3d0a6ae4ee/

U2 - 10.3390/min13010036

DO - 10.3390/min13010036

M3 - Article

VL - 13

JO - Minerals

JF - Minerals

SN - 2075-163X

IS - 1

M1 - 36

ER -