Bedrock deformations in northeastern Estonia based on ground-penetrating radar data

Abstract

The Vaivara Deformation Zone (VDZ) in northeastern Estonia was studied with ground-penetrating radar (GPR). While the typical Paleozoic carbonate plateau in northern Estonia is characterized by a subhorizontal continuous reflection pattern in GPR images, the VDZ, located south of the erosional bedrock escarpment, known as the Baltic Klint, frequently contains deformed and tilted limestone blocks, thrusts, and folds. We categorize the structural features seen in the GPR images according to deformation intensity and show their areal distribution. In addition to the VDZ, bedrock segments are deformed in Tõrvajõe village, the Pähklimäed Hills, and Narva town, whereas the distribution and nature of deformations hint at a glaciotectonic origin. The study confirms that GPR is a suitable tool for discovering and interpreting bedrock structures. Auxiliary geological and geophysical techniques are required for outlining of bedrock blocks.

Keywords

• glaciotectonic deformations
• paleozoic bedrock
• quaternary
• ground-penetrating radar
• vaivara deformation zone
• sinimäed
• narva
• estonia.