About Diamonds of the Ingul-Ingulets Domain (the Ukrainian Shield)

Three finds of diamonds on the Ingul-Ingulets domain of the Ukrainian Shield are considered: in breccia-like rocks of the Gruzke area, in eclogite-like rocks in the basin of the Ingul River and the Zeleny Gayi meteorite crater. A brief description of these diamonds is made, which represent their different geological and genetic types. Тhe veracity of these diamond findings and the origin of their crystals are appreciated. It is shown that 8 diamonds of the Gruzke area differ in size (0.2-1.4 mm), shape, colour, set of nitrogen centres and degree of preservation. According to infrared spectroscopy, all the studied crystals can be attributed to natural diamonds of the mantle type and distinguish them into separate groups, as they belong to several spectral types: IIa, IaAB, Iab and Ib. However, there are several doubts about the veracity of this finding: 1. Finding in small samples of the core wells of such a high concentration of diamonds. 2. A large variety of crystals in these samples by spectral types of physical classification. 3. Signs of mechanical wear on all crystals, which does not exclude the version of their origin from a diamond drill bit (a mixture of crystals of the natural and possibly synthetic diamond). The question of whether the found diamonds belong to the breccia-like rocks of the Gruzke area remains open. Small diamonds (up to 0.3 mm), which are found in eclogite-like rocks in the basin of the Ingul River on several grounds (mainly cubo-octahedral habit, manifestations of skeletal forms of growth, flat surface of the cube faces, yellow-green colour, inclusions) are very similar to crystals of synthetic HPHT diamond. However, the same small diamonds are found in the rocks of the Euro-Asian Alpine and the Ural and Central-Asian Caledonian ophiolite belts and the eruptions of modern volcanoes in Kamchatka. Such diamonds are also found in lamproite-like rocks of the Mriya pipe in the Azov Sea region, and they are found in weathering crusts and terrigenous deposits of Ukraine. It is necessary to find out the true nature of these findings. Therefore, it is necessary to audit all finds of such diamonds in Ukraine. It is shown that diamonds from the Zeleny Gayi meteorite crater are typical impact apographitic crystals - diamond paramorphoses on graphite. The conclusions of some researchers about the mantle nature of these diamonds from this crater are denied.

The Ilyinetsmeteorite crater - geological structure unique in Europe and a promising destination for international tourism

The Ilyinets meteorite crater is located in Lypovets and Ilyinets districts of Vinnytsia region. It is accessible for examination in quarries near Luhova and Ivanky villages in the Sobok River valley. This site currently has the status of a geological natural landmark of local significance. The crater appeared as a result the impact of a meteorite on Precambrian surface of the Ukrainian Shield 445 million years ago. The impact of the explosion caused the formation of a typical ring structure about 8.5 km diameter and 600-800 m deep. The denudation level in the crater area is estimated at about 300-400 m. Thus, the preserved part of the crater has a diameter of about 3.2 km and is 400 m deep. Target rocks are represented mainly by granitoids of the Haisyn (Sobite) complex. The meteorite crater consists of impactites: shock-melt rocks, impact bombs, allogenic and authigenic breccia (suevite, tagamiteetc). Genesis of impactites is confirmed by the findings of stishovite, koesite, impact-type diamond, the presence of metallic and silicate spherules, planar structures in quartz, feldspars and other characteristic features. Overlap rocks are represented by sporadically distributed Devonian and widespread Quaternary sediments. Their thickness reaches 13 m, and it decreases to 3 m in the Sobok River valley. The Ilyinets meteorite crater is the most representative in Europe because it is easily accessible for examination and study, and available for sampling. Undoubtedly, it is a promising unique geological object that can attract attention of tourists around the world, as well as geoscientists interested in studying unique natural sites and phenomena in Europe and on the Earth in general.