KARAKTERISTIK ALTERASI DAN MINERALISASI DI DAERAH RORAHKADAL, KECAMATAN CIBALIUNG, KABUPATEN PANDEGLANG, PROVINSI BANTEN
| Main Author: | Gunadarma |
|---|---|
| Format: | bachelorthesis doc-type application/pdf Bachelors |
| Bahasa: | ind |
| Terbitan: |
, 2013
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| Online Access: |
http://repository.unpad.ac.id/frontdoor/index/index/docId/124130 http://repository.unpad.ac.id/files/124130/https%3A%2F%2Fmedia.unpad.ac.id%2Fthesis%2F270110%2F2007%2F140710070095_a_6993.pdf http://repository.unpad.ac.id/files/124130/https%3A%2F%2Fmedia.unpad.ac.id%2Fthesis%2F270110%2F2007%2F140710070095_c_2348.pdf |
Daftar Isi:
- SARIDaerah penelitian terletak pada cebakan emas Cibaliung, KecamatanCibaliung, Kabupaten Pandeglang, Provinsi Banten. Daerah Rorahkadal secarageologi terletak pada komplek batuan beku Honje dan disusun oleh batuan bekuvulkanik Miosen yang mengalami alterasi dan mineralisasi. Penelitian mencakupstudi alterasi dan mineralisasi dengan metode penelitian yang dilakukan yaituanalisis petrografi, analisis mineragrafi dan analisis inklusi fluida.Tipe alterasi yang terbentuk di daerah Rorahkadal ada dua yaitu tipepropilitik dan tipe silisifikasi dengan kumpulan mineral-mineral ubahan yang adadi daerah Rorahkadal yaitu silika, klorit, mineral lempung, epidot, kalsedon danoksida besi.Pembentukan mineralisasi di daerah Rorahkadal yaitu pirit, kalkopirit dansfalerit. Mineral bijih tersebut hadir berupa urat sulfida (stockworks), tersebar(disseminated) dalam masadasar batuan, serta hadir pada permukaan batuan.Asosiasi mineral-mineral bijih tersebut dapat mengindikasikan adanyapengkayaan Au di daerah Rorahkadal. Mineralisasi di daerah Rorahkadaldipengaruhi oleh kekar yang secara regional berarah utara selatan.Berdasarkan pengukuran inklusi fluida diketahui bahwa temperaturhomogenisasi (Th) berkisar antara antara 120~229 °C dengan rata-rata Th=191.5°C, temperatur leleh (Tm) berkisar antara -0,18~-0,94 °C dengan rata-rata Tm= -0,65 °C dan salinitas fluida hidrotermal berkisar antara 0,32~1,67 wt% NaCl eq.dengan rata-rata salinitas = 1,53 wt% NaCl equivalen.Berdasarkan data tersebut dapat dikatakan bahwa pembentukanmineralisasi di daerah Rorahkadal dipengaruhi oleh beberapa proses hidrotermal.Gejala overprint di daerah Rorahkadal dibuktikan berdasarkan asosiasi mineralubahan, asosiasi mineral bijih, serta karakteristik inklusi fluidanya. DaerahRorahkadal berada pada lingkungan epitermal sulfidasi rendah pada kedalaman190 meter serta berada di atas boiling level yang terletak pada horizon logammulia.iiiABSTRACTStudy area is located at Cibaliung gold deposit that administratively is apart of District Cibaliung, Pandeglang Sub Province, Banten Province.Geologically this area belongs to Honje igneous rocks complex in whichdominated by Miocene volcanic igneous rocks that already have been alteratedand mineralized. Objective of the research is studying alteration andmineralization process by using some methods, such as Petrography analysis,Mineragraphy analysis and Fluid Inclusion analysis.The study area composed by prophylithic alteration and silicificationalteration. Associated alteration minerals such as silica, chlorite, clay minerals,iron oxide, epidot and chalcedony.Mineralization process at Rorahkadal, such as : sulphide group (pyrite,chalcopyrite and sphalerite). The ore minerals was formed as stockworks,disseminated minerals within groundmass of rock and coating minerals on thesurface of the rocks. The ore minerals associated can showing indicated that Auand other precious metal enrichment in Rorahkadal Area. Mineralization atRorahkadal area controlled by activities of sheer that regionally trending North-South.Based on fluid inclusion measurement, the temperature homogenization isin range 120~229 °C with Th average is191.5 °C, temperature melting (Tm) is inrange -0,18~-0,94 °C with Tm average is -0,65 °C and salinity of fluidhydrothermal is in range 0,32~1,67 wt% NaCl equivalent, with average salinity isabout = 1,53 wt% NaCl equivalent.Based on the data said above that mineralization in Rorahkadal area isinfluenced by more than one hydrothermal processes. Overprint indication atRorahkadal area is proven by association of alteration minerals, association ofore minerals and characteristic of fluid inclusions. Furthermore, we can say thatRorahkadal area is in stage at low sulphidation epithermal environment at depth190 m and above boiling level on precious metal horizon.