International precious 
 metals exploration 
 company 

Company releases

  • Sep 22, 2017 Holding(s) in Company
  • Sep 20, 2017 Director/PDMR Shareholding
  • Sep 15, 2017 Interim Results

Rassoshinskaya

Location and infrastructure


Rassoshinskaya is situated in the Srednekansky and Omsukchansky districts of the Magadan region and covers the basins of the Bulun and Vizualnaya rivers as well as middle reaches of the Korkodon River. There is no nearby infrastructure. There is no scheduled transport to the area and it is accessible only by offroad vehicles or helicopters. The nearest commercial airport is located 350 kilometres to the Southwest at Seimchan. Seimchan is the district capital. Ovoca believes it is possible to use navigable waterways in the area, namely the Kolyma and Korkodon river systems, to get within 100 kilometres of the Rassoshinskaya license area and any future mining site.


Geology


The Rassoshinsky area is confined to the uplift of the same name which is a structural element of the Yukagisrky Block of the Omolonsky Middle Massif. This structure is well defined as series of concentric structures. The massif contains the Olcha - Kubakinskaya controlling structure which spatially controls the location of the Rassoshinskaya project area and the Avaldinsky district which hosts the Kubaka deposit. Additionally, the structural elements of the Omolonsky Middle Massif including the Olcha - Kubakinskaya controlling structure is visible on satellite image.

Excerpt from SRK report

Sedimentary, igneous and metamorphic formations of Archean to Jurassic in age predominate in the region often covered by upper Quaternary and recent sediments. The Archean rocks are documented from the Dremuchii, Olcha and Drevnii basins in the South of the Rassoshinskaya area, in the Vizualnaya and Pravaya Vizualnaya rivers basins and in the Northern part of the Rassoshinskaya area. The rocks are mainly represented by amphibolite, biotite-amphibolite and garnet-biotite gneisses, which are usually migmatized and granitized to varying degrees. Similar to the Prikholymsky uplift, the Vendsky complex includes pre-Devonian terrains and carbonate sediments which are widely developed within the area and which usually do not contain organic remains, as well as less well developed igneous formations. The Ordovician sediments are represented by limestone and dolomite with interbedded feldspar-quartz sandstones.

The Devonian sediments are represented mostly by red volcanogenic sediments. The most typical rocks are rhyolites, dacites and their associated tuffs. Lavas, andesitic tuffs, albititized basalts, tuff conglomerates, tuff gravels and tuff sandstones are less well developed. Sediments of the upper Permian formation are developed in the basin of the Pravaya Ragulia, Centralnii, Ogromnii and Poslednii streams, where they transgress earlier formations. They are mainly represented by fine-grained polymictic sandstones and organogenic limestone. Gravels, siltstones and mudstones are found in the form of interlayers and lenses. Triassic sediments are developed on the margins of the Permian sediments and are represented by mudstones, siltstones, fine sandstones, tuff siltstones and tuff sandstones with limestone interlayers.

Jurassic formations are found within the area reviewed as small-sized outcrops which are mainly represented by fine sandstones with interlayers of siltstones and mudstones including secondary layers of gravels and conglomerates.

Outcrops of intrusive rocks which occupy around 8% of the deposit area are represented by relatively large granitoid massifs, minor intrusions and sub volcanic bodies and dykes composed of felsic to ultrabasic rocks. Structurally, the Rassoshinsky uplift is bounded by the Olchanskoye deep-seated fault in the East, by the Namyndukansky fault in the North and by a section of the Bulun-Nenkalsky fault zone in the West. Archaean basement blocks are located across the Rassoshinsky uplift represented to a varying degree by granitized gneisses, amphibolites and the schists. The main structures of the Rassoshinsky uplift are the Rassoshinsky horst-anticline (in the north) and the Khebekendzhinski horst-anticline (in the south), the Nelginsky intrusive-dome upheaval (in the centre) and the Arykimbinsky trough-syncline (in the east). The uplift area is split into blocks by numerous multidirectional faults. The largest of which are the Olchanskoye faults which divides the Rassoshinsky uplift and the Dolomnanskaya depression, as well as the Bulun-Nenkalsky, Namyndukansky and Omsukchansky faults which bound the uplift in the West, in the North and in the Northeast respectively. In the South, the uplift is bounded by the Tebaninsky suture zone.

Four ore districts were delineated at the Rassoshinskaya license (from North to South): Podgornensky, Bulunsky, Nelginsky and Khebekendzhinsky.

Gold mineralization of Podgornensky Ore District is related to quartz, quartz-chlorite, carbonate-quartz veins and quartz stockwerk zones. Numerous surface streams host alluvial gold deposits, 12 tonnes of gold was mined there historically. 

Mineralisation at Bulunsky and Nelginsky Ore Districts represents gold-quartz, qold-silver and gold-silver-base metal formations and forms vein, stockwork and mineralized zone occurring.

Gold-silver mineralization at Knebekendzhinsky Ore District is related to low-sulphide epithermal type well known in the Russian Far East. 

Excerpt from SRK report      

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