Identification of a Hidden Volcano in an Open-pit Coal Mine by Gravity Survey, NW Bohemia

0440209 - GFÚ 2015 RIV NL eng C - Conference Paper (international conference)
Mrlina, Jan
Identification of a Hidden Volcano in an Open-pit Coal Mine by Gravity Survey, NW Bohemia.
Proceedings of the 20th European Meeting of Environmental and Engineering Geophysics - Near Surface Geoscience. Houten: EAGE, 2014, Tu PA2 03/1-Tu PA2 03/5. ISBN 978-94-6282-027-2.
[Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics. Athens (GR), 14.09.2014-18.09.2014]
Institutional support: RVO:67985530
Keywords : hidden volcano * coal mine * gravity survey
Subject RIV: DC - Siesmology, Volcanology, Earth Structure

Volcanic structures often form significant part of sedimentary basins. They represent a serious obstacle to seismic and magnetic surveys, but may become a focus in rift basin description. We encountered a different case – an assumed volcanic structure in the forefield of an open-pit brown coal mine. To confirm the presence of such a hidden volcanic body we performed a gravity survey in very challenging topographic and noise conditions at the edge of the mine. Final complete Bouguer anomalies were treated by various filtering techniques including residual separation, horizontal gradients, vertical derivatives, etc. We extracted a positive residual gravity anomaly and delineated its extent from the gradient data. As well, we studied rock samples densities and porosity. It was found that the assumed volcanic rock (trachyandesite) and partly the related breccias exhibit significantly higher density than the surrounding and overlaying Tertiary sediments of the Most Basin.
Permanent Link: http://hdl.handle.net/11104/0243356