The Obukhov Formation is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

Belarus Belarus, officially the Republic of Belarus, is a landlocked country in Eastern Europe. It is bordered by Russia to the east and northeast, Ukraine to the south, Poland to the west, and Lithuania and Latvia to the northwest. Belarus spans an a ...

and

Ukraine Ukraine is a country in Eastern Europe. It is the List of European countries by area, second-largest country in Europe after Russia, which Russia–Ukraine border, borders it to the east and northeast. Ukraine also borders Belarus to the nor ...

that dates to the

Late Eocene The Priabonian is, in the International Commission on Stratigraphy, ICS's geologic timescale, the latest age (geology), age or the upper stage (stratigraphy), stage of the Eocene epoch (geology), Epoch or series (stratigraphy), Series. It spans ...

; the Obukhov Formation is equivalent to the Prussian Formation of

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

Rovno amber Rovno amber, occasionally called Ukrainian amber, is amber found in the Rivne Oblast and surrounding regions of Ukraine and Belarus. The amber is dated between Late Eocene and Early Oligocene, and suggested to be contemporaneous to Baltic amber ...

is found in this formation, and 90% of amber collected from the Obukhov Formation is extracted illegally and the trade is controlled by armed organised crime groups, although the

Ukrainian government The Cabinet of Ministers of Ukraine (), commonly referred to as the Government of Ukraine (), is the highest body of state executive power in Ukraine. As the Cabinet of Ministers of the Ukrainian SSR, it was formed on 18 April 1991, by the Law ...

has begun to oversee excavations since 1993.

Geological context

The

is hosted in the Obukhov Formation, and it underlies the

Early Oligocene The Rupelian is, in the geologic timescale, the older of two age (geology), ages or the lower of two stage (stratigraphy), stages of the Oligocene epoch (geology), Epoch/series (stratigraphy), Series. It spans the time between . It is preceded b ...

Mezhigorje Formation. The formation is found along the northwestern margin of the Ukrainian Crystalline Shield exposed in the Rivne region of Ukraine and across the border near

Rechitsa Rechytsa or Rechitsa (, ; ; ) is a town in Gomel Region, Belarus. It serves as the administrative center of Rechytsa District. The town is located on the Rechytsa River, which flows into the Dnieper. In 2020, its population was 66,400. As o ...

in the Gomel Region of

. The granite

basement rock In geology, basement and crystalline basement are crystalline rocks lying above the mantle and beneath all other rocks and sediments. They are sometimes exposed at the surface, but often they are buried under miles of rock and sediment. The baseme ...

was overlain by sandy to clayey deposits that were host to alluvial amber. The two formations total between in thickness, both containing interbeds or mixtures of brown coals and carbonized vegetation. Both formations are sandy to clayey in texture, with the Obukhov Formation having more clayey

glauconite Glauconite is an iron potassium phyllosilicate ( mica group) mineral of characteristic green color which is very friable and has very low weathering resistance. It crystallizes with a monoclinic geometry. Its name is derived from the Greek ...

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

plus sandy

loess A loess (, ; from ) is a clastic rock, clastic, predominantly silt-sized sediment that is formed by the accumulation of wind-blown dust. Ten percent of Earth's land area is covered by loesses or similar deposition (geology), deposits. A loess ...

References

Geology of Belarus Geologic formations of Ukraine Amber {{geologic-formation-stub