Artikel Ilmiah : H1F009021 a.n. FUJI ANBARI
| NIM | H1F009021 |
|---|---|
| Namamhs | FUJI ANBARI |
| Judul Artikel | STUDI ALTERASI DAN MINERALISASI BERDASARKAN PENGAMATAN CONTO INTI PEMBORAN DAERAH GRASBERG BLOCK CAVE (GBC), DISTRIK GRASBERG, KABUPATEN MIMIKA, PAPUA |
| Abstrak (Bhs. Indonesia) | Daerah penelitian berada di daerah tambang tembaga - emas porfiri yang merupakan Kontrak Karya “A” PT. Freeport Indonesia. Secara geografis lokasi penelitian berada pada koordinat 734000 mE – 734800 mE, 9550600 mN - 9551800 mN tepatnya di Daerah Grasberg Block Cave (GBC), Distrik Grasberg, Kabupaten Mimika, Papua. Secara fisiografi daerah penelitian termasuk ke dalam Rangkaian Pegunungan Tengah (Central Mountain Range) dengan barisan pegunungan yang mencapai ketinggian 3000-4000 mdpl. Berdasarkan empat sumur pemboran, satuan batuan daerah penelitian tersusun dari tua ke muda, yaitu Satuan Marmer Tua, Satuan Batugamping, Satuan Marmer Muda, Satuan Andesit Fragmental, Satuan Monzodiorit Porfiri, Satuan Monzodiorit, dan Satuan Monzonit. Dari hasil pengamatan megaskopis dan mikroskopis (mineragrafi dan petrografi) didapatkan lima zona alterasi di daerah penelitian, yaitu (1) Zona Kuarsa-K-feldspar-Biotit±Magnetit, (2) Zona Kuarsa-Serisit-Pirit, (3) Zona Pirit-Magnetit, (4) Zona Kuarsa-Garnet-Epidot, dan (5) Zona Garnet-Epidot±Aktinolit. Zona densitas urat kuarsa di daerah penelitian terdiri dari zona densitas urat kuarsa melimpah (>10%), zona densitas urat kuarsa sedang (5-10%), zona densitas urat kuarsa jarang (1-5%), dan zona densitas urat kuarsa sangat jarang (<1%). Mineralisasi sulfida utama yaitu kalkopirit dan bornit. Zona mineralisasi sulfida khususnya kalkopirit di daerah penelitian terdiri dari zona mineralisasi kalkopirit melimpah (>2%), zona mineralisasi kalkopirit sedang (1-2%), zona mineralisasi kalkopirit rendah (0.5-1%), dan zona mineralisasi kalkopirit sangat rendah (<0.5%). Mineralisasi hadir baik dalam urat maupun tersebar acak. Berdasarkan hasil analisis, terdapat hubungan antara penyebaran densitas urat kuarsa dengan keterdapatan mineralisasi kalkopirit di daerah penelitian. Semakin tinggi densitas urat kuarsa daerah penelitian maka semakin tinggi pula mineralisasi kalkopirit, dan sebaliknya. Selain itu, mineralisasi kalkopirit juga hadir tersebar acak dalam batuan. |
| Abtrak (Bhs. Inggris) | The research field set in gold-copper porphyry mine area within the Contact of Work - COW “A” PT. Freeport Indonesia. Geographically, the study site is located at 734000 mE – 734800 mE, 9550600 mN – 9551800 mN in Grasberg Block Cave (GBC) area, Grasberg District, Mimika Regency, Papua. Physiographic areas of research including into Central Mountain Range with elevation 3000-4000 above sea level. Based on examination of four drill holes shows that lithology in research area from old to young are Marmer Unit from Faumai Formation, Limestone Unit, Marmer Unit from Kais Formation, Fragmental Andesit Unit, Monzodiorit porphyry Unit, Monzodiorit Unit, and Monzonit Unit. From macroscopic and microscopic (mineragraphy and petrography) analysis, there are five alteration zones in research area, (1) Quartz-K-feldspar-Biotite±Magnetite Zone, (2) Quartz-Sericite-Pyrite Zone, (3) Pyrite-Magnetite Zone, (4) Quartz-Garnet-Epidote Zone, and (5) Garnet-Epidot±Actinolite. Quartz vein density zone in research area consist of abundant quartz vein density zone (>10%), moderate quartz vein density zone (5-10%), rare quartz vein density zone (1-5%), and very rare quartz vein density zone (<1%). Chalcopyrite and bornite are prominent sulphide mineralizations. Sulphide mineralization especially chalcopyrite zone in research area consist of abundant chalcopyrite mineralization zone (>2%), moderate chalcopyrite mineralization zone (1-2%), low chalcopyrite mineralization zone (0.5-1%), and very low chalcopyrite mineralization zone (<0.5%). Mineralization is present both in vein and disseminated. Based on analysis result, there is a relationship between quartz vein density and chalcopyrite mineralization distribution. The higher quartz vein density, the higher chalcopyrite mineralization content, and vice versa. Besides chalcopyrite mineralization is also present disseminated on the rocks. |
| Kata kunci | Kata kunci: Grasberg, GBC, porfiri, zona alterasi dan mineralisasi, densitas urat kuarsa, Papua. |
| Pembimbing 1 | Adi Candra S.T., M.T |
| Pembimbing 2 | Siswandi S.T., M.T |
| Pembimbing 3 | - |
| Tahun | 2014 |
| Jumlah Halaman | 11 |
| Tgl. Entri | 2014-11-21 01:44:33.722935 |