Alexander Semenovich Makhnach (08.12.1918, v. Hotlyany, Uzda district, Minsk region – 17.10.2006), geologist. Academician of the National Academy of Sciences of Belarus (1970; corresponding member since 1959), Doctor of Geologo-Mineralogical Sciences (1959), Professor (1960). Honored Scientist of the BSSR (1980). Member of the Great Patriotic War.
Works on the lithology and geochemistry of the Upper Proterozoic, Devonian, Cambrian, ancient weathering crusts, facies and formation analysis, paleogeography, magnetism, volcanism, tectonics, minerals (oil, mineral salts, iron ore, etc.). Member of the search and discovery of deposits of potash and rock salts in Belarus. Developed stratigraphic schemes of the Upper Proterozoic and Cambrian sedimentary strata. He studied lithology, paleogeography and minerals of the Riphean, Vendian, Cambrian and Devonian deposits in Belarus, the crystalline basement and the weathering crust developed on it. He summarized and analyzed materials on geology of Belarus for the last 35-40 years, received new data on stratigraphy, lithology, paleogeography and minerals of the sedimentary sequence, compiled (in collaboration) new stratigraphic schemes of the Riphean, Vendian, Cambrian and Devonian sediments and compared them with similar formations of adjacent regions of Russia, Ukraine, Poland, Lithuania.
Author of more than 400 scientific papers, incl. 34 monographs.
State Prize of the BSSR in 1972 for the discovery and exploration of large oil fields of the Pripyat oil and gas region of the BSSR.
Awarded with the Order of Lenin (1979), the Red Banner of Labor (1971), the Badge of Honor (1966), World War of the II degree (1986), Francisk Skaryna (1999), the Medal For Bravery (1942), and other medals.