Application of geophysical prospecting techniques to evaluate geological-mining heritage: The Sinapismo mine (La Carolina, Southern Spain)

- Proposal to use drainage adit for alternative tourism
- Characterization of the drainage adit employing geophysical prospecting techniques
- ERI provides a general characterization of a mine.
- Lithological alternance, layer dip and associated faults detected using GPR.

Geological-mining heritage is a valuable resource that deserves proper attention given its educational, scientific, landscape, and cultural worth. The significant geological and mining wealth of the abandoned metallogenic district of La Carolina (Southern Spain) is particularly interesting in this regard. This study is focused on one of the emblematic veins of this district, the Sinapismo vein, and more specifically, on the “La Paloma” drainage adit, stretching a total length of 1170 m.A geological and geophysical study was conducted in the interior of this drainage structure to assess its heritage value as well as the condition of the mine voids with a view to converting the mine into a site open to the public. Electrical Resistivity Imaging (ERI) provides a general characterization of the mine, highlighting the vergence of the geological structure and the main faults and veins. Ground Penetrating Radar (GPR) offers higher resolution but provides a limited depth of penetration (less than 3 m in this case). Profiles have been constructed using 500 MHz and 250 MHz shielded antennas to assist the analysis of the lithological alternance (quartzites and phyllites), layer dip, and the various associated fault and vein families.The position of the Sinapismo shaft with respect to the La Paloma drainage adit will permit an itinerary for visitors to be designed along the first 480 m of the tunnel because it will allow for the proper location of two evacuation points (the shaft and the entrance to the adit). According to the results obtained from ERI and GPR studies, access to the rest of the drainage tunnel by visitors is inadvisable for safety reasons due to the existing fracture networks and the presence of veining.The two geophysical techniques applied in this study (ERI and GPR) provide, on the one hand, complementary information to the geological observations, which can be used to evaluate the geo-mining heritage. On the other hand, they offer information about the geomechanical conditions of the rock mass, thus permitting a safety assessment of access to the La Paloma adit.