Home – Home – Jornals – Russian Geology and Geophysics 2001 number 5

Luminescence, absorption, and internal morphology of diamonds from alluvium of tributaries of the Lower Tunguska River have been studied and compared with the same characteristics of diamonds from the Malaya Botuobiya and Daldyn-Alakit kimberlite fields, closest to the Tungusskaya area. The color of diamond from the Tungusskaya area is determined by the high concentration of N3 centers, by plastic deformations, as well as by the fact that some crystals contain radiation defects with different degrees of thermal transformation. Band N3 as well as H3 and H4 dominate in photoluminescence spectra.
Multistage growth, specific for diamonds from highly diamondiferous sources, is not typical of the investigated diamonds. Nevertheless, though most diamonds have a homogeneous internal structure, which is characteristic of lowly diamondiferous primary sources, the investigated collection contains individual diamonds of complicated multizonal anatomy with the internal structure typical of highly diamondiferous kimberlites.
The obtained data suggest that the diamonds from the Tungusskaya area have no genetic relation to the known primary sources of the Yakutian kimberlite subprovince. The fact that the collection of diamonds from the Tungusskaya area contains crystal groups with contrasting and sometimes mutually excluding characteristics suggests their origin from several sources.
A conclusion is made that unknown kimberlite bodies exist either within the platform or within its southern folded frame.