Geochemical Features and Mineral Associations of Differentiated Rocks of the Norilsk 1 Intrusion

Abstract

The purpose of this study is to show the patterns of distribution of disseminated sulfide in layered rocks based on the numerous geochemical and mineralogical data obtained for eight boreholes of the Norilsk intrusion (southern part of the Norilsk 1 deposit). There is a common trend of sulfide liquid fractionation in the Main Ore Horizon, which is composed of picritic and taxite (or olivine) gabbro-dolerites: the Ni/Cu in both rock types decreases down all sections, indicating an increase in the degree of fractionation of the sulfide liquid from top to bottom. On the contrary, the Ni/Fe ratios in pentlandite increase in this direction due to an increase in sulfur fugacity. However, picrite and taxite/olivine gabbro-dolerites are very distinctly separated by Ni/Cu values: these values are >1 in picritic gabbro-dolerite while they are always <1 in taxite/olivine gabbro-dolerite. These rock types are distinguished by sulfide assemblages. The first includes troilite, Fe-rich pentlandite, chalcopyrite, cubanite, talnahite, bornite and copper (low sulfur association); the second one is composed of monoclinic pyrrhotite, chalcopyrite, Ni-rich pentlandite and pyrite (high sulfur association). A two-stage magma injection with different ore specializations is supposed for picritic and taxite/olivine gabbro-dolerites.

Pd/Pt IMBALANCE IN LAVAS AND INTRUSIONS OF THE NORILSK-TALNAKH ORE REGION

“…Полученные значения Pd/Pt отношений в целом согласуются с опубликованными ранее [Naldrett, 2004;Tolstykh et al, 2020], но имеются некоторые различия. В общем виде, исходя из данных [Naldrett, 2004], возникает ощущение, что Pd/Pt отношение на каждом месторождении растет от вкрапленных руд к массивным.…”

“…Следовательно, дифференциация руды по этому минералу могла бы приводить к вариациям Pd/Pt отношения. Наиболее полные аналитические данные по ЭПГ на сегодняшний день приводятся в работе [Tolstykh et al, 2020] по ряду скважин южной части месторождения Норильск-1. В этой работе обнаружена обратная корреляция Pd/Pt и Ni/Cu отношений, т.е.…”

“…Несмотря на долгую историю изучения лав и интрузий в Норильск-Талнахском районе, на этот факт не обращали внимания. Известно также, что различные типы руд разных месторождений характеризуются широким разбросом значений Pd/Pt отношений -от 0.6 до 12.0 для различных месторождений [Naldrett, 2004;Krivolutskaya, 2016;Tolstykh et al, 2020] со средним значением, равным 3 [Naldrett, 2004]. Однако при этом либо не приводится количество анализов для осреднения, по которым рассчитаны эти значения, либо не дается описание типов пород [Naldrett, 2004;Krivolutskaya, 2016].…”

Atypical Mineralization Involving Pd-Pt, Au-Ag, REE, Y, Zr, Th, U, and Cl-F in the Oktyabrsky Deposit, Norilsk Complex, Russia

“…The observed trend of Ni-enrichment in pentlandite (Figure 19) may reflect a progressive rise in the level of sulfur fugacity, f S 2 (cf. [36,37]).…”

Evaluation of Ni-Cu Ore from Zapolyarnoe Based on Mineralogical and Physical Properties before and after Comminution

“…This research assessed the relationship between mineralogical and physical properties and the results of selective comminution in crushing using copper-nickel samples from Zapolyarnoe, one of Russia's largest polymetallic deposits. Zapolyarnoe is part of the Norilsk deposit, which is known for its significant concentrations of platinum group elements (PGEs) [28] and is located on the north-western edge of the Siberian platform in the Russian Arctic and hosts massive amounts of Ni-Cu ore [29]. The geodynamic conditions of this area were controlled by rifting and re-activation of the intra-continental basins [30].…”