TY - JOUR

T1 - Deformation features of super-deep diamonds

AU - Ragozin, Alexey

AU - Zedgenizov, Dmitry

AU - Shatsky, Vladislav

AU - Kuper, Konstantin

AU - Kagi, Hiroyuki

PY - 2020/1

Y1 - 2020/1

N2 - The paper presents new data on the internal structure of super-deep (sublithospheric) diamonds from Saõ-Luiz river placers (Brazil) and from alluvial placers of the northeastern Siberian platform (Yakutia). The sublithospheric origin of these diamonds is supported by the presence of mineral inclusions corresponding to associations of the transition zone and lower mantle. The features of morphology and internal structure have been studied by optical and scanning electron microscopy (SEM), cathodoluminescence topography (CL), and electron backscatter diffraction (EBSD) techniques. Diamonds typically have complicated growth histories displaying alternating episodes of growth, dissolution, and post-growth deformation and crushing processes. Most crystals have endured both plastic and brittle deformation during the growth history. Abundant deformation and resorption/growth features suggest a highly dynamic growth environment for super-deep diamonds. High temperatures expected in the transition zone and lower mantle could explain the plastic deformations of super-deep diamonds with low nitrogen content.

AB - The paper presents new data on the internal structure of super-deep (sublithospheric) diamonds from Saõ-Luiz river placers (Brazil) and from alluvial placers of the northeastern Siberian platform (Yakutia). The sublithospheric origin of these diamonds is supported by the presence of mineral inclusions corresponding to associations of the transition zone and lower mantle. The features of morphology and internal structure have been studied by optical and scanning electron microscopy (SEM), cathodoluminescence topography (CL), and electron backscatter diffraction (EBSD) techniques. Diamonds typically have complicated growth histories displaying alternating episodes of growth, dissolution, and post-growth deformation and crushing processes. Most crystals have endured both plastic and brittle deformation during the growth history. Abundant deformation and resorption/growth features suggest a highly dynamic growth environment for super-deep diamonds. High temperatures expected in the transition zone and lower mantle could explain the plastic deformations of super-deep diamonds with low nitrogen content.

KW - Deformation

KW - Diamond

KW - Electron backscatter diffraction

KW - Internal structure

KW - MATO-GROSSO

KW - JUINA AREA

KW - INFRARED-ABSORPTION

KW - NATURAL DIAMOND

KW - NITROGEN AGGREGATE

KW - MINERAL INCLUSIONS

KW - diamond

KW - LOWER MANTLE DIAMONDS

KW - internal structure

KW - DISSOLUTION

KW - SAO LUIZ

KW - deformation

KW - PLASTIC-DEFORMATION

KW - electron backscatter diffraction

UR - http://www.scopus.com/inward/record.url?scp=85077317767&partnerID=8YFLogxK

U2 - 10.3390/min10010018

DO - 10.3390/min10010018

M3 - Article

AN - SCOPUS:85077317767

VL - 10

JO - Minerals

JF - Minerals

SN - 2075-163X

IS - 1

M1 - 18

ER -