Kukersite

Kuckersit or Kukersit ( after the village Kukruse, dt Kuckers ) is a reddish brown sedimentary rocks from the Ordovician of Estonia and northwestern Russia, which is flammable due to its high oil content and is expected to the oil shales. It forms the basis of an important industry in Estonia.

The term " Kuckersit " was used in 1916 by Mikhail Dmitrievich Salesski first time, before the rock was called " Kuckersche layer" and " Kuckerscher fire shale ".

Rock description

Kuckersit is a slate-like, predominantly fine-grained rock from light to dark brown color. In places, it is up to the naked eye identifiable fossils ( ostracods ( Ostrakoda ) and bryozoans ( Bryozoa ) ) rich. Under an optical microscope it can be seen that it consists largely of organic structures. In some places, irregular black lenses of asphalt minerals are recognizable. The rock is rich in oil, the oil content can be up to 46% of the rock, making it one of the world highest oil content in oil shales. In addition to organic matter silicates and aluminosilicates occur and a high for an oil shale lime content. In contrast to the similar Dictyonema Ordovician shales, which are common in northern Estonia and Sweden, the content of Kucksersite of heavy metals is low. The formation of the rock changes, and within the rock occur limestone layers and tubers.

Formation

In large parts of the Ordovician continental area were flooded. In Central and Northern Europe emerged calcium deposits in shallow seas, including the Baltic states. In the area of ​​today's Kuckersits large amount of blue-green algae of the species Gloeocapsomorpha prisca were deposited in shallow sea, it formed a marine gyttja. Based on comparisons with similar modern deposits depth is assumed of not more than four meters to the sea area in which the Kuckersit arose.

Occurrence

Kuckersit is areally distributed on the eastern tip of the Gulf of Finland as often repeated involvement in limestones of Kõrgekallas and Viivikonna formation of the Middle Ordovician of Estonia and Russia before. In these 20 to 30 m thick limestone sequences were counted up to 50 individual layers of Kuckersit and Kuckersit -like rocks that have few centimeters to a maximum of two to three meters in thickness. Over the lower part of this sequence in Estonia and Russia digested main occurrence, the major part of the mining operations on itself, exists in the upper part of the sequence, the so-called tapa camp, which is found mainly south of Tapa in Estonia.

The rock is digested more than 90 kilometers from Tallinn to Saint Petersburg, alone in Estonia, the area of its distribution area more than 50,000 km2. The layers of rock fall flat to the southwest and are proved by drilling to about 60 kilometers south of the coast. The total reserves in Estonia are estimated depending on the source to about 6 to 21 billion tons.

Use

The oil shale was known to the residents of the Gulf of Finland for a long time and was used by them as fuel. The scientific investigation began in 1697 with one of Peter I to Holland to study skillful sample. The results of the studies were not published until the early 19th century. Johann Gottlieb Georgi described the stone in its 1791-1798 published in Königsberg font Geo- physical and natural historical description of the Russian empire to list of previous knowledge of the same type.

First degradation experiments on a larger scale have been made in the area of Kukruse since the 1880s, industrial reduction was only from 1916 in Russia. The first major development for the extraction of oil from Kuckersit was taken in 1924 in Kohtla -Järve in operation. Until 1940, mainly diesel and lubricants were produced, and wood preservatives and bitumen from oil shale. At that time, nearly 10 % of Estonia's export earnings from oil shale were obtained.

Today Kuckersit covers 62 % of the oil needs of Estonia and especially in the area of energy supply is important. The recovery of oil from the Kuckersit obtained by mining in so-called Kiviter retorts and Galoter retorts. Another use of Kuckersit in power generation, in the building materials as well as in the chemical industry.

The production will take place today in the east of the country around Kohtla -Järve and Narva by the company Eesti Põlevkivi place in the late 1990s there were still six mines to 80 m deep and four surface mines. Larger deposits are mainly still west of Kohtla -Järve demonstrated, but not yet mined (as of 1999). The extraction and use of Kuckersit in Estonia today is just in sight yet competitive for energy from natural gas or coal, and is a depletion of inventories. The industrial mining of Kuckersit has caused major environmental problems that the mining regions weigh heavily on today.

In Russia Kuckersit has also been reduced, but not to as great an extent as in Estonia. Even today there are still mining sites between St. Petersburg and the Estonian border.