The development of Evenkia mineral-raw materials base is closely connected with the industrial exploitation of oil-and-gas deposits which take the main positions in the development of East-Siberian oil-and-gas complex.

Five oil and gas

Five oil and gas deposits were found in the region: Yurubcheno-Tohomsky, Kuyumbinsky, Sobinsky, Omorinsky and Paiginsky with industrial oil and gas reserves of 1100 mln.t.

These reserves (picture 1) allowed to form the foundation of raw materials base in two large oil-and-gas extracting regions: Yurubcheno-Tohomsky and Vanavarsky.

Both regions are unique not only in Russia, but also in the world because of their gasogenic and oil-bearing range and helium content in gas (0,20 - 0,56%). Yurubcheno-Tohomsky, Kuyumbinsky and Sobinsky deposits can be basic. Gas extraction presents the main industrial interest on Sobinsky deposit.

The foundation of oil-and-gas extracting industry should solve several tasks: the supplying of oil extraction deficit in Russia owing to putting into operation the new deposits; the transport organization of extracting gas (oil and passing) to the consumer; providing Krasnoyarsk region and Evenki Autonomous Area with gas; Area participation in the projects of oil and gas transportation to the countries of Asian-Pacific region.

The main feature of raw material base of hydrocarbons in Evenki Autonomous Area is its insufficient validity which is closely connected with poor territory study. The prospecting of reserves ( reserves % C1+C2 are from the total sum of extracting reserves) in the region is 7,7%. It means that reserves of Evenki Autonomous Area are in the initial stage of study and it indicates about the presence of preconditions for strengthening of raw material base of hydrocarbons.

The efficiency of geological prospecting works on oil and gas in the region is rather high. The results of geological prospecting works in Yurubcheno-Tohomsky zone are the following: oil efficiency is 376 t/m, gas efficiency is 554 thousand m3/m. In the west and south-west parts of this zone (Yurubcheno-Tohomsky area) the efficiency of geological prospecting works is rather higher: oil - 1371 t/m and gas - 1731 thousand m3/m.

The main reserve of efficiency raising of oil and gas works is the inclusion of mapping methods in the process of hydrocarbon deposits search. These methods should be widely adopted in the zones of protuberance of vend thickness. Also they should be adopted in the searching of reef accumulation in the south regions of Evenkiya, prognosis estimation of their reef-paleozoic oil-and-gas bearing in the North-Tungus oil-and-gas bearing region.

Essential increase of efficiency in geological prospecting works could be achieved on the territory of distributed fund of the entrails of the earth. April and Verhnekosvinsky raisings could be perspective objects on the territory of Kuyumbinsky and Tersko-Kamovsky areas. The speeding up of searching works on these areas could be a result of commercial discovery. On the territory of Yurubchensky area the zones of protuberance of vend stratums on the south of Yurubcheno-Tohomsky deposit are also could be perspective zones.

Omorinskaya zone of oil-and-gas accumulation is situated on the south of Evenkiya. The wide spreading of structural-lithological oil and gas traps could be found in this zone. The south-west slope of Kamovsky vault is covered by this zone. Omorinsky gas-condensate deposit was opened in this zone in the trap of lithological type.The sandstones of Katangsky suite venda are very productive. The main direction of searching works in Omorinsky zone is the searching of structural-lithilogical traps in Vanavara suite venda. All this will allow to strengthen the raw material base of region (picture 2).

Within the bounds of Omorinsky region on the Evenkiya territory were outlined several structural-lithological traps with the help of method complex (seismo-prospecting OGT, direct searching and subject investigations). These traps are Chegalbukanskaya, Yaduliskaya, Nekorakskaya. SNIIGG MS recomended to include these traps in the list of licence objects (according to the traps figures). In 2000 high-accurate seismo-prospecting works with OGT method were done within the bounds of Chegalbukansky trap. The presence of this prognosis trap was completely confirmed .

In future within the complex of the territory of north-east parts of Krasnoyarsk region the lands of Tanachinsky oil and gas bearing region will be perspective. They will be involved in the process of hydrocarbon searching. Nijne-Tungusky zone is situated within the bounds of Tanachinsky oil and gas bearing region. This zone has indications of oil and gas bearing.

The area of joining of Katangsky and Nepsko-Botuobinsky parts, and zone of Sobinsko-Teterinsky megaswell should be put into searching estimation and licence.

The intensification of searching works on the enumerated territories will allow to make more active the use of entrails of the earth in the zones of undistributed (passive) funds of the entrails of the earth.

Solid minerals

The following kinds of raw materials are priority on the present stage: diamonds, coal, graphite, gold and platinum, optical calcite, phosphate raw materials, rare metals and semi-precious stone raw materials. In future considerable perspectives are closely connected with copper-nickel and iron-ore, abrasive and mineral paints. The region has its own fuel-power resources and inexhaustible reserves of different building materials that allows their complex usage. This fact is very important for the development of the region and mining industry.

Coal

In Evenkiya three coal deposits were prospected and are reckoned on the balance. They are the following: Noginsky, "Yuktakon" and "Chopko".The works are in the stage of reserves calculation on the deposit "Korablik" which was found recently. There are several objects which were faintly studied in this area. The perspective of these objects is very high. These are the prognosing deposits Verhnemoierinskoye, Srednepelyatkinskoye, Vodopadninskoye, Bugariktinskoye, Chirindinskoye. There can be no doubt that new large objects will be opened during further region study. It is supposed that the importance of Tungusky coal basin will increase in future.

Noginskaya graphite-coal bearing structure is of great interest. Noginsky coal deposit and also several prognosing deposits are situated within the bounds of Noginskaya graphite-coal bearing structure. In this region the coal bearing is closely connected with accumulations of Pelyatkinsky suite of upper-permsky age. The coal consists of various grainy sandstones of quartz-fieldspar and quartz structure with lens of gravelit, alevrolit and argelit. 20 coal-beds were found on this object. 4 of them have thickness of the coal vein from 1,7 up to 9,6 m. Nowadays balance reserve of coal on Noginsky deposit form on categories A+B+C1 more than 6000 thousand t.

Coal deposit "Chopko" was found within the bounds of Maimechenskoy coal bearing structure. Balance reserve of coal on this deposit form on categories A+B+C1 about 100 thousand t.

Coal deposit "Yuktakon" was found within the bounds of Verhnemoierokanskoy coal bearing structure. Balance reserve of coal on this deposit form on categories A+B+C1+C2 more than 2000 thousand t.

Coal deposit "Korablik" was found on Ust-Taimurinsky area. Nowadays searching-estimation works are conducting here. 3 coal-beds with thickness of the coal vein (from top to bottom) of 14.0, 6.0 and 1.5 were found. Estimated resources on category P1 form about 3 mln.t. In 2001 the calculation of coal reserves of ? area of deposit was finished. These calculations were confirmed by special committee.

Graphite

The most perspective and industrially important objects (well-known and prognosing deposits) are situated in the west part of Tungusky coal basin, within the borders of Noginsky graphite bearing structure (which is situated in the basin of down and middle stream of the river Nijnaya Tunguska). This is the only region in Krasnoyarsk district, Taimyrsky and Evenkia Autonomous Areas where the extraction of graphite was made (Noginsky deposit) to the last time.

Krasnoyarsk graphite plant works on the raw materials of this region. Industrial operated Noginsky deposit was found within the bounds of this region. Prognosing deposits Maksimovsky, Belogorodsky and Verhnenoginsky were also found within the bounds of this region. Total resources of these deposits are estimated in the amount of 5500 thousand t. and more.

Picture 3. Pier for graphite dispatch of Noginsky mine on the river Nijnaya Tunguska.

Diamonds

Several potential diamond-bearing regions are situated on the territory. They are: Maimecha-Kotuisky, Ilimpeisky, Velminsky, Katangsky and Tychansky. Single finds of diamond crystals in river-bed and terrace accumulations were found in these regions. The most perspective (from the point of view of native diamond-bearing) regions are Maimecha-Kotyisky and Tychansky.

Nowadays native sources of diamonds are known only in Maimecha-Kotyisky region on Haramaisky cimberlit field (picture 4.). Haramaisky field is situated in the inter-rivers Kotyi and Moiero. It occupies the territory about 1500 km2. The level of diamond-bearing is corresponding to Luchakansky, Kuranahsky and Kuonapsky fields of mesozoic cimberlits of Yakutia.

Picture 4. Diamonds of Haramaisky cimberlit field.

The total prognosis resources of Haramaisky cimberlit field are: on category P1+P3 about 20 mln. carat.

Nowadays the most perspective is Tychansky diamond-bearing region. It is situated in the middle-stream of the river Podkamenaya Tunguska. It is bearing on the largest structure of Siberian platform --Baikitskaya antekliza . It has resemblance with Nepsko-Botuobinsky antekliza of Yakutia (geological construction and the time of display of cimberlit magmatism). Exposing plots with diamond collectors witness about the connection of diamonds with middle-paleozoic (D3 - C1) phase of cimberlit magmatism of Siberian platform. In Evenkia the appearance of diamond-bearing can be found in Nembinsky field of mesozoic cimberlit. Diamond-bearing collectors are situated in the basins of the rivers Tarydak, Shushuk, Tychany.

Quality of diamonds in collectors is rather high, jewelry diamonds form about 63 % (picture 5). That's why the territory of Evenkia Autonomous Area (and first of all Tychansky diamond-bearing region) is perspective because of diamond-fields.

Picture 5. Diamonds of Tychansky region.

Gold

Gold was found in the basins of the rivers Nijnaya Tunguska, Podkamenaya Tunguska, Chunya and Tetere. The most perspective areas are Chernorechenskaya, Ilimpeiskaya and Vanavrskaya.

Chernorechenskaya area includes four deposits. In this place gold was found in alluvial accumulations of terraces. Standard sample has up to 48 signs of gold. The total resources of this area are estimated in 3740 kg.

Vanavara area is perspective in gold-fields.

Ilimpeisky area has endogenous and exogenous types of gold-bearing ore.

The region which is situated in the upper-stream of the river Ilimpeya is of great interest. The river vale and its tributaries have heightened content of gold. The most important object is the deposit of stream Gold Kutum. Here gold was found in the river-bed and terrace accumulations with content from 0,74 up to 1.0 g/m3. Such objects were found in the vale of river Ilimpeya and its tributaries: Olle, Umnoga, Limptekan. Total prognosis resources are 31 t. in this region.

Besides the enumerated regions on the territory of Evenki Autonomous Area the following regions are of the great interest (from the point of view of gold-bearing): Esseisky mountain-mass on the north of the region, Rytelsky ore region in the vale of the river Chunya and Velminskaya deposits group in the vale of the river Velmo.

Optical calcite

All well-known deposits of optical calcite on the territory of Russia are concentrated in Evenki Autonomous Area. The largest Tungus (Middle Siberian) spar-bearing province was found here. This province is connected with late-mesozoic and early-mesozoic toleit-basalt formation. Two main spar-bearing regions were found within the borders of province. These regions are characterized by the development of different deposits types. In the lava field the following spar-bearing regions were found: Haiksky, Voevolihinsky, Tutonchansky, Vivinsky, Tembenchinsky, Srednekochechumsky, Turukansky and Nijnetungusky.

Within the borders of the tufa field the following spar-bearing regions were found: Chunsko-Ilimpeisky, Taimurinsky, Chuyungovsky and Kimchunsky.

26 deposits and 166 appearances of iceland spar and a lot of points of mineralisation were found in the lava field on the territory of Evenki Autonomous Area. All these deposits of optical calcite are situated in the vale of the river Nijnaya Tunguska and its tributary the river Nidym.

Picture 6. Optical calcite.

Within the borders of tufa field all deposits of iceland spar spatially connected with large breaking violations mainly in north-east and north-west extends.

Copper, nickel, cobalt.

Nowadays there were not found the large objects of non-ferrous metals on the territory of Evenki Autonomous Area. At the same time a lot of deposits of copper, copper-nickel, copper-nickel-cobalt ore are known within the borders of perspective zones and structures where the signs of norilsk type ore were found.

The following ore regions are situated on the territory of Evenki Autonomous Area: Romanihinsky, Severorechensky, Erachimsky, Bilchansky and Oneksky.

Complex anatit-magnetit deposit "Essey" is timed to the same name alkaline-ultra-main mountain-mass. Magmatic deposit is closely connected with the following minerals - iron, apatite, zirconium, rare lands, strontium, fluorine, ochre and possible platinum. Two ore types were found here - phoscorit (calcite-apatite-magnetit) and nelsonit (apatite-magnetit). The south solid of apatite-carbonate-magnetit ore was found on the deposit. It was timed to two of the same name geological solids - main, which has the character of steep-falling powerful vein and small one, which is situated not far from the first solid. This deposit is unique.

It is possible that the deposit has gold and platinum, that's why it is of the great industrial interest.

Semi-precious stone raw materials.

The existence of jewelry-article stones are developed rather wide, especially in the north and east parts, where they are genetically connected with developing fields of trias formations.

Nowadays this kind of raw materials is in popular demand on the world market, that's why the territory of the region is in the great interest because it has all preconditions for the opening of large objects with their further exploitation which doesn't require a lot of expenditures.

Platinum group elements.

Evenkia potential in platinum was not studied enough. Although there are preconditions for discovering of objects of industrial meaning.
On the territory of Evenki Autonomous Area four the most perspectives areas (where platinum elements can be found) were chosen: Esseiskaya, Kureisko-Severninskaya, Ilimpeisko-Chunskaya and Nijnetunguskaya.

Other minerals.

Besides above-named solid minerals there are considerable perspectives for discovering of industrial deposits of other minerals on the territory of region.

The unique region is situated in Evenkiya. Large objects of strontium ore were found here. These are the following prospecting deposits: Bolshedovogninskoye, Yvakitskoye, Maloyvakitskoye, Pesirskoye with total prognosis resources of more than 15,5 mln.t. SrO. According to the modern demands deposit can be perspective for industrial exploitation in the case, if it contains in average 20-25% of celestin. On the above-named objects such content is much higher.

Several large significant objects of phosphate raw materials were prospected in the region. Also there is the complex of metal minerals with large iron and rare metals resources. Nowadays they were not studied enough, that's why their economic meaning is not clear. The existing preconditions allow to consider Evenkiya territory the perspective zone with large objects of metal minerals. The presence of virgin copper within the bounds of Avamsky metalliferous province in Tymerokansky ore region is of great interest. The following kinds of raw materials are also very important: peat, abrasives, mineral paints, building materials, resources.

Evenkiya is rich in brines which contain lithium, iodine, bromine. Unique deposits of underground mineral water with industrial meaning were prospected in the region. The region has difficult situation with water supply. It is quite possible to use underground water for local population and also in medical purposes.

The territory of Evenki Autonomous Area has a wide range of minerals part of which has large and unique objects of earth usage. The attraction of investments for industrial exploitation of deposits would allow the effective capital investment for a long perspective from one side, and solving of wide range of social-economic problems in the region from the other side.

Flinted (fossilized) wood

Fossilized wood is often met along the river-bed of Nijnaya Lakura on the territory of Evenki Autonomous Area.

Fossilized wood consists of minerals mixture (silica-opal + chalcedony or quartz). Organic components of wood never turn into stone. They are removed and replaced by silica. Then pseudo-morphozm is formed. Pseudo-morphozm is usually grey or brown, but sometimes it can be red, pink, light-brown, yellow, blue or violet. Grinding and polishing makes the colour richer. Fossilized wood can be used for the decorative art and jeweller's art.

Fossilized wood in Lakursky region presents the fragments of trunks weighing 20-50 kg and more. Content - flint and monolith.

Nowadays the articles from fossilized wood are in popular demand on the world market, that's why this kind of minerals deserves the attention.