Majhgawan Diamondiferous Pipe, Madhya Pradesh, India - A Review
Subscribe/Renew Journal
On the other hand the typical carrot shape of the plug, almost concentric distribution of diamonds, mode of presence of mantle-derived xenocrysts, overall chemistry with high MgO(25%) low K2O(1%) and fair amounts of Cr and Ni are highly characteristic of kimberlitic nature. Broad petrographic characters coupled with abundance of xenocrysts and occurrence of country rock xenoliths and geochemical charecteristics suggest it is in several aspects typical kirmberlite rather than lamproite. The garnet population with fair amount of harzburgitic pyrope and larger share of lherzolitic variety indicate characteristics almost intermediate between kimberlite and lamproite.
Irrespective of the nature of the diatreme in any exploration model for search of new primary sources in the area, the spesific nature of HIM of the Majhgawan rock has to be kept in view (i.e.rather less abundance of garnet that too more of group-9 type, predominance of high magnesia spinellchromite, absence of ilmenite etc). The Majhgawan diamonds (42% gem) are predominantly curve faced modified forms indicating signs of resorption.
Keywords
Abstract Views: 193
PDF Views: 3