Dobele impact structure in latvia: Review of archived reports for future

Latvia is a State near Baltic Sea formerly included in Soviet Union that hardly classified all types of cartographical and geological information making it not available for scientific evaluation. Geological mapping data, deep boreholes with cores available from various depth up to crystalline basement (>1km), intersections and seismic data from 60-ties indicate the existence of an enigmatic structure similar to structural forms called astroblemes; it is located south of the town of Dobele in Latvia N56°35’ E23°15’. The structure at the beginning was suspected as kimberlitic pipe; however, gravimetric and magnetometer data did not approve these suspicions. The impact crater formed in between Late Triassic and Early Quaternary time; the age is not known precisely and one of versions of evolution of structure is possible explosion of a meteorite 2-5 km high above the land. Hydrogeological and geochemical data is contradictory to structural evidence therefore, a new survey including modern geophysical methods is highly recommended. The aim of this paper is reviewing of archived classified data from expedition reports of geological mapping events never published before and emphasize the need to recover hidden data about the formation of Dobele impact structure according to available research data and recommend future research approaches to shed light on unclear questions. The field geological mapping expedition was in charge during whole study of Dobele structure. The most devoted person to find the answers of development of the Dobele structure was Mr. Atis Murnieks, who left this world in summer 2017.