Detection of near-surface geological heterogeneity at Starunia palaeontological site and vicinity (Carpathian region, Ukraine) based on microgravity survey

Abstract

Results of a microgravity survey performed in the abandoned Starunia ozokerite mine (Carpathian region, Ukraine), where in the early 20th century well preserved remains of large, extinct mammals were found, are discussed in the paper. A number of gravity anomalies indicating the geological heterogeneity at the sub-Quaternary strata have been observed. The assumed measurement observations also enabled the authors to interpret the results in view of density changes in the Quaternary strata. Most of the registered microanomalies coincide with the high-halite and ozokeritic Miocene salt-bearing Vorotyshcha beds. The distribution of the microanomalies reveals neither their correlation with the thickness of overburdens, nor any gravity impact of numerous abandoned wells. Gravity anomalies were mostly connected with the lithology of sediments and rocks obtained from geological boreholes drilled in the years 2007 and 2008, on the basis of which the anomalies' origin could be determined. A concentric, relatively negative gravity microanomaly of ca. 25 m in diameter was registered in the place, where very well preserved relics of the woolly rhinoceros had been found. They may be indicative of the existence of Pleistocene lakes (and/or palaeoswamps), into which the woolly rhinoceroses had sunk. Hence, an assumption can be made that the further search for successive zoological relics can be made in areas with similar anomalies under the low-density sub-Quaternary subcrop.