Interpretation of 2D-Subsurface Resistivity Data in Iron Ore Prospect Area of Eastern Binangun Coastal Area, Cilacap Regency, Central Java

Interpretation of 2D-subsurface rock resistivity data has been carried out in an iron ore prospect area of Eastern Binangun Coastal in ​​Cilacap Regency, Central Java. The background of this research is the potential for iron sand reserve in this area for prospective exploitation. The research was conducted using a magnetic method in 2017 to map the distribution patterns of the local magnetic anomalies, interpreted to originate from the distribution of iron ore in the subsurface. In 2018, the research continued using the 2D-resistivity method to find out the lithology section in the subsurface of the research area. 2D-resistivity data acquisition is carried out on four tracks consisting of Bng-01 to Bng-04. By modeling the resistivity data, true resistivity value have been produced for each track in form of the subsurface resistivity section, which includes the Bng-01 track is 2.27 – 44.1 Ωm; the Bng-02 track is 4.5 – 58.6 Ωm; the Bng-03 track is 6.37 – 63.4 Ωm; and the Bng-04 track of 4.98 – 83.3 Ωm. After the interpretation process, some models of subsurface rocks lithology section is obtained under the four trajectories. It is inferred from the process that the rocks consists of sand interspersed with gravel (> 58.6 Ωm); sand containing iron ore grains (28.2 – 83.3 Ωm), clayey sand (11.1 – 32.9 Ωm), sandy clay (4.98 – 13.5 Ωm), and fine sand which intruded by saltwater (<6.49 Ωm). Sand containing iron ore grains is the main part of the coastal aquifer; hence exploitation of iron sand will potentially reduce the function of aquifer in storing and ducting groundwater and causing of abrasion in the Eastern Binangun Coastal area.

FULL PAPER (PDF) can be accessed in website of JGEET:
journal.uir.ac.id/index.php/JGEET/article/view/2139