As is known, the geochemical zonality of primary halos is expressed in changes in the qualitative composition of associations and quantitative ratios of elements - indicators within the zone of mineralization and is one of the most important parameters widely used in prediction and estimation of the scale of hidden mineralization at depth on the basis of geochemical studies.

Geochemical criteria are established on the example of one of the fields in Yakutia. Climatic conditions predetermined the widespread development in the area of permafrost up to a depth of 300 m.

The deposit is confined to the southern periclinal closure of the anticline, composed of a monotonous thickness of calcareous-clay siltstones and shales. The rocks are characterized by abundance of pyrite and marcasite nodules. The rocks are not characterized faunistically, but lithologically they parallel the Kukkan Formation of the Lower Permian of the unified stratigraphic scheme of the Southern Verkhoyany. The mineralization is localized in crushing and buckling zones of near meridional strike and in quartz veins of near-latitudinal strike. Both have a steep dip at an angle of 70-80°; the zones are westward, and the veins are northward ...

Numerous aspects of the extremely complex problem of zonality of postmagmatic ore deposits have been considered for several decades by many Soviet and foreign researchers - V. Emmons, S. S. Smirnov, Y. A. Bilibin, N. A. Khrushchev, P. M. Tatarinbv, V. I. Smirnov, V. V. Shcherbina, Y. Kutina, etc.

The Nezhdaninskoye gold deposit is located in the northern part of the South Verkhoyansk synclinorium and is situated in the vaulted part of the southern periclinal closure of the box-shaped Dybinskaya anticline. The intervening rocks are represented by a monotonous thickness of sandy siltstones and shales of Lower Permian age.

All the most interesting in practical terms deposits and ore occurrences within the South Slope of the Gissar Range are hydrothermal in nature and localized within the zones of rupture faults. In this connection, geochemical sampling of the material composing the zones of tectonic faults becomes extremely important, because it is obvious that the basic patterns of element introduction or removal in the faults can be used as geochemical criteria for age dissection of faults or assessment of prospects for their metalliferousness.

According to the law of universal dispersion of chemical elements (Clark-Vernadsky law) in each drop or dust particle of matter on our planet can be found all the elements of the Mendeleev table. Their quantitative ratio in different shells of the globe and more local geological objects is determined by the nature of each element - its individual geochemical features. The closeness of geochemical (chemical and physical) properties is due to the similar behavior of elements in geological processes and joint accumulation in certain geological formations or shells of the globe. The latter circumstance makes it possible to subdivide chemical elements into a number of categories according to geochemical features and, first of all, according to their relative abundance in various geological objects or shells of the globe.

The liquation type of magmatic deposits proper includes commercial accumulations of disseminated sulfide copper-nickel ores, which occur in rocks of basic-ultrabasic composition (norites, gabbro-norites, olivine diabases, pyroxenites, peridotites). According to modern ideas, the formation of liquation-type deposits occurs by separation of magma into immiscible liquids - silicate and sulfide even before the onset of crystallization. The isolated sulfide secretions merge into droplets and under the influence of high specific gravity sink to the bottom parts of intrusions, where they form accumulations. Deposits of liquation disseminated ores are syngenetic with the host rocks. Consequently, the primary halos of these deposits are also syngenetic. The degree of study of the conditions of formation of deposits of this genetic type is clearly insufficient, so the following ideas about the occurrence of halos of syngenetic disseminated ores and the interpretation of these halos can be satisfactory only insofar as they correspond to the accepted liquation-magmatic hypothesis of formation of the ores themselves.

The copper-nickel sulfide ore deposit under consideration is located in the northern part of the Tersko-Notozersky anticlinorium, composed predominantly of Archean rocks of the Kola series. Genetically and spatially, it is associated with a multilayer intrusion of ultrabasic rocks (olivinites, harzburgites) that are significantly metamorphosed. The intrusion is a series of bedded and lenticular bodies occurring in the nuclear part of the brachianticline, composed of rocks of the Kola gneiss series ...