https://jgsm.geologi.esdm.go.id/index.php/JGSM <p><strong>Jurnal Geologi dan Sumberdaya Mineral (Journal of Geology and Mineral Resources)</strong> is an Indonesian scientific journal published by the Center for Geological Survey, Geological Agency, Ministry of Energy and Mineral Resources. The journal receives Indonesian or English articles. Those articles are selected and reviewed by our professional editors and peer reviewers.</p> <p>JGSM has been assigned as an Accredited Scientific Periodical Magazine by the Indonesian Institute of Sciences (LIPI) No. 596/Akred/P2MI-LIPI/03/2015 in 2015, followed by Kementerian Riset dan Teknologi / Badan Riset dan Inovasi Nasional No. 200/M/KPT/2020 in 2020. The journal is indexed in <a title="portal_garuda_IPI" href="http://id.portalgaruda.org/?ref=browse&amp;mod=viewjournal&amp;journal=10104" target="_blank" rel="noopener">Indonesian Publication Index (IPI)</a>, <a title="isjd" href="http://isjd.pdii.lipi.go.id/index.php/public_no_login/index_direktori" target="_blank" rel="noopener">Indonesian Scientific Journal Database (ISJD)</a>, <a href="http://dx.doi.org/10.33332">Digital Object Identifier (DOI)</a> and <a title="google_scholar" href="https://scholar.google.co.id/citations?user=nXMHIYUAAAAJ&amp;hl=en" target="_blank" rel="noopener">Google Scholar</a>, the contents are freely available in electronic version. JGSM is published quarterly in February, May, August, and November.</p> <p><a title="issn" href="http://issn.pdii.lipi.go.id/issn.cgi?daftar&amp;1402376294&amp;1&amp;&amp;" target="_blank" rel="noopener"><strong>ISSN : 0853-9634 (print)</strong></a></p> <p><a title="eissn" href="http://issn.pdii.lipi.go.id/issn.cgi?daftar&amp;1485227549&amp;1&amp;&amp;" target="_blank" rel="noopener"><strong>e-ISSN : 2549-4759 (online)</strong></a></p> <p><strong><em><strong>DOI Prefix: </strong></em><a title="JGSM" href="https://doi.org/10.33332">https://doi.org/10.33332</a><br /></strong></p> Pusat Survei Geologi en-US Jurnal Geologi dan Sumberdaya Mineral 0853-9634 <p>Authors who publish articles in <strong>Jurnal Geologi dan Sumberdaya Mineral (JGSM.Geologi)</strong> agree to the following terms:</p><ol><li>Authors retain copyright of the article and grant the journal right of first publication with the work simultaneously licensed under a <strong>CC-BY-NC</strong> or <strong>The Creative Commons Attribution–ShareAlike License.</strong></li><li>Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal.</li><li>Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See <a href="http://opcit.eprints.org/oacitation-biblio.html" target="_blank">The Effect of Open Access</a>)</li></ol> https://jgsm.geologi.esdm.go.id/index.php/JGSM/article/view/945 <p><em>The Mount Tampomas Geothermal Area is located in Sumedang Regency, West Java Province. This study aims to interpret the distribution of subsurface fault structures based on gravity data analysis over an area of 14 × 14 km². Residual gravity anomaly analysis reveals the presence of a low gravity anomaly in the central part of the volcanic edifice, which is interpreted as a low-density zone associated with a magma ascent pathway within the volcanic system. The results of derivative analysis, correlated with surface geological data, indicate the presence of fault structures comprising normal faults, strike-slip faults, and reverse faults, which represent structural patterns predominantly controlled by volcanic activity. Forward modelling applied to several profiles yields the subsurface lithological density distribution, including the Subang Formation (2.40 g/cm³), Kaliwangu Formation (2.35 g/cm³), old volcanic lahar breccia (2.85 g/cm³), undifferentiated volcaniclastic tuffaceous sand (2.55 g/cm³), pumiceous tuff (2.60 g/cm³), breccia and agglomerate (2.70 g/cm³), and young volcanic lava (2.50 g/cm³).The results of this study provide a preliminary characterization of subsurface fault structures in the Mount Tampomas Geothermal Area based on gravity methods.</em></p> <p><em><strong>Keywords</strong> : Gravity, Geothermal, Tampomas, Derivative </em><br /><em>Analysis, Forward Modelling</em></p> Sultan Ahmad Syarifuddin Suharsono Suharsono Iqbal Takodama Copyright (c) 2026 Sultan Ahmad Syarifuddin, Suharsono, Iqbal Takodama http://creativecommons.org/licenses/by-nc/4.0 2026-02-28 2026-02-28 27 1 1 15 10.33332/jgsm.geologi.v27i1.945