| NIM | H1F012069 |
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| Namamhs | ARYANTO ZIDNI WICAKSONO |
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| Judul Artikel | GEOLOGI DAN STUDI GENESA URAT KUARSA PADA SISTEM VEIN PONGKOR DAERAH CISARUA DAN SEKITARNYA, KECAMATAN NANGGUNG, KABUPATEN BOGOR, JAWA BARAT |
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| Abstrak (Bhs. Indonesia) | Daerah penelitian berada di gunung Pongkor, yang secara administratif terletak di dalam wilayah Kecamatan Nanggung, Kabupaten Bogor, Provinsi Jawa Barat. Walaupun persebaran urat umumnya mengikuti jalur rekahan yang diterobosnya, namun kenyataannya persebaran urat umumnya tidak menentu, kadar Au pada vein yang satu dan yang lainya berbeda, serta menurut Marcoux dan Milesi (1999), proses pembentukan vein Gunung Pongkor secara multi stage vein fill sehingga membuat penulis mencoba untuk membuat genesa urat kuarsa berdasarkan karateristik urat, tekstur urat, perpotongan antar urat kuarsa, serta mineral penyusun urat dan dihubungkan dengan konten Au dan Ag pada Daerah Cisarua dan sekitarnya. Metode yang digunakan berupa pemetaan geologi dan alterasi permukaan, serta pengambilan data pada tunnel. Sedangkan analisis conto berupa analisis petrografi, analisis mineragrafi, dan analisis spektral menggunakan ASD Terraspec. Berdasarkan karateristik geologinya daerah penelitian didominasi oleh batuan piroklastik dan intrusi kubah lava andesit dasitik sedangkan struktur geologi yang terbentuk didominasi oleh sesar mendatar kanan berarah NW-SE pada periode 1 dan sesar mendatar kanan berarah N-S pada periode 2 yang berperan sebagai jalur mineralisasi urat kuarsa. Berdasarkan genesanya, urat kuarsa pada daerah penelitian terbentuk pada stage bervariasi yaitu Early stage terdiri dari kuarsa ± kalsit, stage alpha 1 sebagai precursor vein terdiri dari kuarsa ± adularia ± electrum ± aguilarite, lalu stage alpha 2 yang membentuk urat kuarsa ± kalsit ± adularia ± rodhonit, selanjutnya stage beta 1 sehingga terendapkan urat kuarsa ± pirit ± kalkopirit ± argentite ± aguilarit, pada stage beta 2 terendapkan urat kuarsa ± rodhonit ± kalkopirit ± pirit ± polibasit ± argentit ± wilmenite ± galena, Stage charlie merupakan stage terakhir sebagai endapan banded kuarsa ± rodhonit ± argentite ± aguilarite ± electrum. Konten Au dan Ag semakin banyak seiring meningkatnya stage, dimana puncak konten Au (elektrum) tertinggi pada Stage Charlie sesuai dengan kadar Au/Ag 12.1 ppm (Au) dan 147.5 ppm (Ag) pada tunnel Kubang cicau sedangkan puncak konten Ag (Nativ Ag) tertinggi pada stage Beta 2 sesuai dengan kadar Au/Ag 7.54 ppm (Au), dan 173.2 ppm (Ag) pada tunnel Ciguha. |
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| Abtrak (Bhs. Inggris) | Research area lies in the mount Pongkor, which is located in Nanggung subdistrict area, Bogor regency, West Java Province. Even though vein distribution of veining are generally following the path of fractures, but in fact the distribution of veining are generally uncertain, gold content in the one vein and the other veins are different, and according to Marcoux and Milesi (1999), the process of forming vein in Mount Pongkor is multi stage vein fill, so that is reason the author tries to make genesis based on the characteristic veins of quartz veins, vein texture, the intersection between quartz veins, as well as the constituent mineral in the veins and associated with Au and Ag content in Cisarua Region and surrounding areas. The method was used in the form of geological mapping and surface alteration, as well as data collection on the tunnel. While the analysis of samples in the form of petrographic analysis, mineragraphic analysis and spectral analysis using ASD Terraspec. At this research, the author tried to make genesis of vein based on the characteristic of quartz veins, quartz veins texture, and quartz veins intersection, as well as the constituent mineral veins and associated with Au and Ag content in Cisarua Region and surrounding areas. Based on the geological characteristics, research area is dominated by pyroclastic rocks and intrusive dome of dasitic andesit lava, while geological structures formed predominantly by dekstral fault with NW-SE trend in period 1 and dekstral fault with N-S trend in period 2, which act as line of mineralized quartz vein. Based on genesis, quartz veins in the research area is formed by varety of stage. The Early stage consists of quartz + calcite, Stage Apha 1 as a precursor veins consist of quartz ± adularia ± electrum ± aguilarite, and then Stage Alpha 2 is veins consist quartz ± calcite ± adularia ± rodhonite, the next stage is beta 1 which deposited quartz ± pyrite ± chalcopyrite ± argentite ± aguilarite, on Stage Beta 2 deposited quartz veins ± rodhonite ± chalcopyrite ± pyrite ± polibasite ± Argentite ± wilmenite ± galena, Stage Charlie is the last stage as a precipitate banded of quartz ± argentite ± rodhonite ± aguilarite ± electrum. Au and Ag content increased often stage change, where the highest peak of the Au content (electrum) at the Stage Charlie accordance with Au/Ag assay data on Kubangcicau tunnel is 12.1 ppm (Au) dan 147.5 ppm (Ag), but the highest peak of Ag content (Native Ag) at the Stage Beta 2 accordance with Au/Ag assay data on Ciguha tunnel is Au/Ag 7.54 ppm (Au), dan 173.2 ppm (Ag).
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| Kata kunci | Kata kunci : Emas Ephitermal, Sulfida Rendah, Pongkor, Genesa, Urat Kuarsa. |
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| Pembimbing 1 | Siswandi, S.T.,M.T |
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| Pembimbing 2 | Bronto Sutopo, Ph.,D |
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| Pembimbing 3 | |
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| Tahun | 2017 |
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| Jumlah Halaman | 10 |
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| Tgl. Entri | 2017-01-12 09:15:32.711277 |
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