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PENGARUH STRUKTUR DAN TEKTONIK DALAM PREDIKSI POTENSI COALBED METHANE SEAM PANGADANG-A, DI LAPANGAN “DIPA”, CEKUNGAN SUMATERA SELATAN, KABUPATEN MUSI BANYUASIN, PROVINSI SUMATERA SELATAN Pratiwi, Ragil; Nugroho, Hadi; Widiarso, Dian Agus; Lesmana, Rana
Geological Engineering E-Journal Vol 5, No 2 (2013): Volume 5, Nomor 2, Tahun 2013
Publisher : Geological Engineering E-Journal

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Abstract

The increasing of oil and gas and energy crisis nowadays has been causing the explorationist look forthe new energy sources such as gas in shale and coal which more environmentally friendly. SouthSumatera Basin is one of Indonesian Basin which has a large potency with 183 tcf. Methane gas isstored in natural fracture of coalbeds called cleat. Cleat was produced during coalification andtectonism process.The aim of this study is to evaluate the influence of structures and tectonism processes towards theCBM potency in an area. The research methods were done by desciptive and analysis methods.Descriptive method was done by describing secondary data which contain rock mass data, andanalyzing method was done by analyzing subsurface data consist of seismic and wireline log. Thosedata were used to determine the sweetspot area and calculate gas in place in target zone of CBM.Based on geologic structure analysis, primary orientation trends which configure geologic structuresis northeast-southwest, it is a Compression Phase of Miocene-Recent. This stress configured sincline,sinistral strike-slip fault, and normal faults in tensional phase. The interesting area of CBMexploration or sweetspot area located in the northeast area, with normal faults which control fracturepermeability reach 12,22 mD, high thickness reach 14 – 18 feet (4,7 – 6 meter), and CBM targetdepth of < 6000 feet (2000 meter), and gas in place calculation reach 0,742 tcf. Completiontechniques for CBM target in study area with relatively low permability are hydraulic fracturingcompletion and horizontal well with direction of well is relatively northeast-southwest whichperpendicular with face cleat. 
HUBUNGAN KONDISI GEOLOGI TERHADAP ALTERASI HIDROTERMAL DAN MINERALISASI PADA ENDAPAN EPITERMAL DAERAH BUNIKASIH, KECAMATAN TALEGONG, KABUPATEN GARUT, PROVINSI JAWA BARAT Rahmawati, Saumi; Nugroho, Hadi; Widiarso, Dian Agus; Verdiansyah, Okky
Geological Engineering E-Journal Vol 5, No 2 (2013): Volume 5, Nomor 2, Tahun 2013
Publisher : Geological Engineering E-Journal

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Abstract

Hydrothermal alteration is a changed in the mineral composition of the rock as a result of interaction of hydrothermal fluids with the wall rock involving various geological environments like fault zones and volcanic eruptions zones. Hydrothermal alteration has a very close relationship with the mineralization. Mineralization is a process of inclusion of valuable rare minerals in rocks that form ore deposits. The purpose of this study is to determine the geological conditions of the mapping area and knowing the type of alteration and the relationship between alteration with the developing of ore mineralization. Research methods include field observations survey and continued by analysis methods, conducted in Bunikasih and surrounding areas, Talegong District, Garut regency, West Java. Methods of analysis undertaken include petrology, petrography, Terraspec, and structure analysis. Geological conditions of the study area consists geomorphological unit of structural steep hills and undulating hills of volcanic units (Van Zuidam, 1983). The research area is composed by rocks from old to young volcanic breccia, Andesite Lava, and tuff. Geological structures that are left slip fault of North Cibaliung, right slip thrust fault of South Cibaliung, right slip normal fault of Citutugan-Cibaliung Beet. There are prophylitic alteration (smectite, chlorite, ±illite), argillic (kaolinite, illite, smectite), advanced argillic (kaolinite, illite, alunite, silica), and silicification (vein zone). In the study area there are two types of epithermal, low sulfidation epithermal zone on Bunikasih mineralized was found that quartz manganese vein, chalcedonic vein, crustiform-colloform banded vein, and disseminated pyrite. there are 5 main vein lines with 40-100cm of thickness with a northwest-southeast direction formed on andesite and tuff, due to the style of the extensions that form the structure openings fault trending Northwest-Southeast. At high sulphidation epithermal indication zone in Datarkorot is dominated by advanced argillic alteration. Mineralization occurred is in the disseminated pyrite form and the concentrated hematite oxide mineral, goethite, and jarosite is a condition of changing sulfide mineral acids. Mineralization is controlled by lithology, by tuff unit which is interpreted lithocap of a diaterme breccia generated by a dacite porphyry intrusion.
ANALISIS POTENSI ALIRAN AIRTANAH BERDASARKAN DELINEASI NILAI PERMEABILITAS SEKUNDER, PADA TAMBANG BAWAH PERMUKAAN, CIURUG CENTRAL L. 500, UNIT BISNIS PERTAMBANGAN EMAS, PT. ANEKA TAMBANG TBK, PONGKOR, KABUPATEN BOGOR, JAWA BARAT Iklima, Neli Nikla; Pudjihardjo, Henarno; Widiarso, Dian Agus; Purnama, Yosep
Geological Engineering E-Journal Vol 5, No 2 (2013): Volume 5, Nomor 2, Tahun 2013
Publisher : Geological Engineering E-Journal

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Abstract

Kegiatan penambangan emas yang dilakukan oleh PT. Aneka Tambang Tbk, yang berlokasi di Desa Bantar Karet, Kabupaten Bogor, Jawa Barat, berupa pertambangan tertutup, yaitu pembuatan terowongan bawah tanah untuk pengambilan bijih emas. Penghancuran bijih emas dilakukan dengan metode blasting (peledakan) yang dilakukan pada dinding terowongan yang kerap menimbulkan masalah yang sulit diatasi, yaitu airtanah yang tiba-tiba keluar dengan debit tertentu. Akumulasi dari airtanah akan membentuk genangan air, terutama air yang keluar dengan debit besar, akan sangat mengganggu aktifitas pertambangan seperti gangguan aktivitas pekerja serta gangguan lingkungan seperti banjir.Untuk mengatasi permasalahan airtanah dalam terowongan bawah tanah diperlukan kajian hidrogeologi untuk mengetahui potensi aliran airtanah, berdasarkan besarnya nilai permeabilitas sekunder. Nilai permeabilitas sekunder didapatkan melalui metode scanline, yaitu metode pengukuran rekahan dengan membentangkan tali pada dinding terowongan yang terdapat banyak rekahan dengan panjang dan kemiringan tertentu. Rekahan yang terpotong oleh bentangan tali tersebut diukur besar strike dan dip-nya, serta diamati karakteristik rekahannya, seperti bukaan rekahan (aperture), jarak (spasi), kemenerusan (lenght), material pengisi, bentuk (shape), dan kekasaran (rough).Metode scanline dilakukan pada dinding terowongan yang basah, meneteskan air, dan mengalirkan air. Pada lokasi ramp down (jalur menurun) elevasi 450 (RY – 01), didapatkan hasil permeabilitas rata-rata sebesar 3.6 x 10-4 m/s. Untuk dinding yang teraliri oleh air, nilai permeabilitas yang didapat adalah nilai permeabilitas tertinggi yaitu 2.6 x 10-3 m/s. Sedangkan untuk akses ramp down elevasi 500 (RY – 02) didapatkan nilai permeabilitas yang lebih rendah yaitu 1.3 x 10-5 m/s. Potensi aliran airtanah tertinggi berada pada lokasi RY-01 yaitu STA 3 dan STA 6. Pada kedua stasiun pengamatan ini ditemukan aliran airtanah dengan debit yang kecil, dan untuk STA 6 merupakan akumulasi arah aliran airtanah pada peta kontur MAT. Berdasarkan nilai permeabilitas sekunder dan karakteristik rekahan dari kedua lokasi ini, lokasi RY – 01 memiliki potensi yang lebih besar untuk mengalirkan air, dibandingkan pada lokasi RY – 02.
EKSPLORASI HIDROKARBON DENGAN METODE GEOLISTRIK KONFIGURASI SCHLUMBERGER DAN KONSEP ANISOTROPI, LAPANGAN RA, WILAYAH BENAKAT BARAT, KECAMATAN BENAKAT, KABUPATEN MUARA ENIM, SUMATERA SELATAN Andryantoro, Rio; Hidajat, Wahju Krisna; Widiarso, Dian Agus; Triyono, F.X. Yudi
Geological Engineering E-Journal Vol 6, No 1 (2014): Volume 6, Nomor 1, Tahun 2014
Publisher : Geological Engineering E-Journal

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Abstract

Oil and gas energy still being a high priority industry to support economic of Indonesia, either as source of national income and supply the local energy demands. Development of oil productions decreasing year-by-year, so that, new resources and advance production need to be processed immediately. Oil and gas resources in Indonesia still have a high potential to be developed, one of the high-potential location is Sumatera Island. Tectonic processes made the Tertiary-sedimentary basins in the back of volcanics arc (back arc basin) or in the eastern of Barisan Mountains. South Sumatera Basin was one of those sedimentary basin. Research area located in West Benakat, District of Muara Enim.Among various methods of oil and gas explorations, geoelectric method was chose for th research. This method is relatively simple and inexpensive in cost. Exploration was committed with geoelectric-Schlumberger configuration.  Analysis processed with anistopy concept. Area of geoelectric measurements located in RA Field, Benakat Barat Area, South Sumatera. The length was various for each line depends on  total of measurement stations. The distance between each measurement station is 100 meters with measurements extend 1000 meters in length for each station. Lines which analyzed in this research were line B, D, and J with 53 measurement stations in total, 20 in line B, 17 in line D, and 16 in line J. Data calculation processed with Microsoft Excel until value of medium resistivity acquired. After that, result from calculation processes will be used for 2D modelling using Surfer 8.Based on data calculation and 2D modelling, three hydrocarbon procpect horizons have been interpreted, they are Horizon H1 in depth between 255 – 287 meters with medium resisitivity 0,87 – 6,27 Ohm meter, Horizon H2 in depth between 462 – 483 meters with medium resistivity 2,62 – 11,58 Ohm meter, and Horizon H3 in depth between 595 – 615 meters with medium resistivity 3,04 – 16 Ohm meter.
GEOLOGI DAN ALTERASI HIDROTERMAL DAERAH BANTAR KARET DAN SEKITARNYA, KECAMATAN NANGGUNG, KABUPATEN BOGOR, PROVINSI JAWA BARAT Febriyana, Rizal Dwi; Aribowo, Yoga; Widiarso, Dian Agus
Geological Engineering E-Journal Vol 6, No 1 (2014): Volume 6, Nomor 1, Tahun 2014
Publisher : Geological Engineering E-Journal

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Abstract

Alteration type at zone of mineralization has its own properties and characteristics that often characterized by the presence of mineral assemblage. The existence of alteration zone occurred due to changes mineral composition of rocks as a result of interaction between fluida of hydrothermal and wall-rocks. Alteration of hydrothermal is very closely linked with mineralization. Mineralization is an assembly and accumulation process of valuable rare minerals in the rocks to form ore deposits. Geological studies related to the characteristics and distribution of alteration and mineralization will assist in the planning of exploration process in the area. The aim of this study is to know the condition of geological research area that include variation of morphology, stratigraphy, structural of geology, alteration types are develop in the study area, as well as the relationship between altered minerals the result of hydrothermal alteration to precipitate epithermal mineralization in the study area.The methods used in this study include field mapping, followed by the method of sample analysis. Method of field mapping carried out by observing the lithology, structural of geology, geomorphology and alteration at Bantar Karet and surrounding areas, Nanggung subdistrict, Bogor Regency, West Java . Method of analysis carried out by analysis of petrology, petrography, mineralgraphy , X - ray diffractometer and the structure analysis of the lineament pattern.Lithology of the research area, beginning Early Miocene with sequence from old to young are unit of laminated tuff, unit of volcanic breccia, unit of andesite lava, unit of lapilli tuff, unit of tuff and unit of dacite intrusion. Structural of geology that develop in the study area are joint, fault that related with the lineament pattern, the main direction are Southwest-Northeast and Northwest-Southeast. Geomorphology of the study area was divided into two : the unit of volcanic landforms are very steep mountains and the unit of volcanic landforms are steep hilly. Alteration zones are contained in the study area, becoming three zones, there are Chlorite ± Smectite Alteration Zone (Propylitic), Smectite Alteration Zone - Kaolinite ± Montmorillonite (Argillic) and Silicified Zones. The mineralization exist are dessiminated Pyrite as ore mineral and oxide mineral such as Hematite which is the alteration of Magnetite and Feromagnesian on temperature conditions < 260oC. Characteristics of deposition types that developed in the study area based on the identification of geology, included alteration and mineralization is low sulphidation epithermal.
GEOLOGI, KARAKTERISTIK DAN GENESA ENDAPAN LATERIT BAUKSIT PT. ANTAM (Persero) Tbk, UNIT GEOMIN, DAERAH KENCO, KABUPATEN LANDAK, PROVINSI KALIMANTAN BARAT Ramadhan, Fachrul Rozi; Aribowo, Yoga; Widiarso, Dian Agus; A, Betraz
Geological Engineering E-Journal Vol 6, No 1 (2014): Volume 6, Nomor 1, Tahun 2014
Publisher : Geological Engineering E-Journal

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Abstract

Bauxite mining is one of the business units that started to increase mine in Indonesia because it has considerable economic value in the scale of quantity and quality. One of the prospective locations are in areas Kenco, Landak District, West Kalimantan Province. Kenco is an area that addressed the rest of the development of Cretaceous volcanism consisting of the island of Borneo Volcanic Formations Mensibau with unit members Granodiorite, quartz diorite and diorite, and the Formation of the Kingdom Volcanic Andesite-trachite units and Formations of alluvium and swamp sediment quarter. Bedrock types that tend to be acid-intemediet bauxite will produce certain characteristics that are different from the dominant rock properties of acids or bases. Rock intensively weathered have the potential to form a precipitate lateritic bauxite. Conducted a detailed mapping is the next steps of regional mapping to narrow the area of bauxite mineral mining resource prospects.         Geological aspects and lateritic bauxite deposit genesis process on the site is a very interesting research material. Based on field mapping, Gibsite is the bauxite formed with frame type is the result of weatherin sediment residue on the soil catena. The study area consists of rocks that form lateritisation overburden, soil laterite, iron cap /gossan, saprolite and bedrock layers. Lateritic bauxite deposit formation is largely controlled by bedrock type, time, climate (rainfall), morphology, changes the face of groundwater, and vegetation destruction process involving a series of rocks, minerals leaching, transport and deposition of mineral elements of chemical residues.         Lateritic bauxite sludge characteristics according to the analysis of X-Ray Diffraction (XRD) on a layer of overburden to ore (saprolite layer) shows the mineral composition Nacrite, Kaolinite, Gibsite, Goethite, Quartz, Nordstandite, Hematite, and Dickite. The average mineral formed at neutral pH tends to be acidic by 5-7 and temperatures below 150oC. The analysis of X-Ray Fluorescence (XRF) shows the rock has certain characteristics which, if averaged Aluminum trihydrate (Al2O3) as much as ±33%, Iron (II) trihydrate (Fe2O3) of about ±8.5%, Silicate oxide (SiO2) approximately ± 43%, Titanium oxide (TiO2) approximately ≤1% and total silicate (R-SiO2) approximately ≤7%. Saprolite layer showed a thickening layer on the hillside at an angle of 20 - 25o, while the section near the top of the hill or valley will be thinned. The results showed that the value of XRF levels bedrock formation of bauxite have economic value to the content of Al and Fe but less to a total content of Si and Si.
STUDI PENDAHULUAN DAERAH PROSPEK PANASBUMI BERDASARKAN DATA MANIFESTASI PANASBUMI, GEOKIMIA DAN ISOTOP FLUIDA PANASBUMI KOMPLEK GUNUNG TELOMOYO, KABUPATEN SEMARANG, JAWA TENGAH Hutami, Rizki Trisna; Aribowo, Yoga; Widiarso, Dian Agus
Geological Engineering E-Journal Vol 6, No 1 (2014): Volume 6, Nomor 1, Tahun 2014
Publisher : Geological Engineering E-Journal

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Abstract

Telomoyo Mountain (area) is one of geothermal prospect area in Indonesia which is shown by many geothermal manifestations around the mountain. Telomoyo Mountain (area) is located in two regencies, Semarang and Magelang, Central Java. The purpose of this study is to get vision about geothermal model system in Telomoyo Mountain based on geothermal manifestation data, geothermal fluid geochemistry, and geothermal fluid isotope.Based on manifestation mapping there are two kinds of manifestation, warm spring and alteration. Warm springs are spread in Candi Dukuh and Candi Umbul with neutral pH characteristic and 36oC water temperature. Based on fluid geochemistry analysis the type of fluid is chloride-bicarbonate water, and based on Na-K-Mg comparison the fluid is immature water. Based on isotope 18O and 2H analysis, warm spring has mixed with meteoric water. Altered rocks are found in Desa Dangkel, Desa keningar, Desa Sepakung, and Desa Kendal Duwur with the type of alteration is argillic – advanced argillic. Based on petrography analysis, lithology in this area are andesitic lava, tuff breccia, and pyroclastic breccia. Based on XRD analysis, altered minerals in rock which is argillic type are smectite, halloysite, kaolinite, and jarosite. In rock which has advanced argilic type, there are dickite, phyrophillite, alunite, diaspora, cristobalite, and pyrite. Dickite and alunite mineral are typical mineral for physicochemical environment with acid in pH and 230 – 260 oC in temperature. Candi Umbul and Candi Dukuh warm spring shows the lateral outflow zone of the geothermal system, while advanced argillic alteration shows the upflow zone of geothermal system.
ANALISIS MASERAL DENGAN METODE REFLECTANCE VITRINITE UNTUK MENGETAHUI KUALITAS BATUBARA PADA SUMUR AL 25, LAPANGAN KINTAP, KABUPATEN TANAH LAUT PROVINSI KALIMANTAN SELATAN, PT. ANUGERAH LUMBUNG ENERGI Hakim, Lutfi; Rachwibowo, Prakosa; Widiarso, Dian Agus; Zaqqie, Bagus
Geological Engineering E-Journal Vol 6, No 1 (2014): Volume 6, Nomor 1, Tahun 2014
Publisher : Geological Engineering E-Journal

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Abstract

The spread of coal deposits in Indonesia is quite large, most of coal basin is located in Sumatra and Kalimantan. One of the basin that produce economical coal deposit with value of calories more than 6.000 kal/g in Tanjung Formation is Asam-Asam Basin (Darlan etc, 1999). PT Anugerah Lumbung Energi is one of the coal mining companies with mining working area on Asam-asam basin. Research area  is located  in Kintap field, Tanah Laut Regency, South Kalimantan. The aim of this research is to find out about coal quality using maceral analysis with vitrinite reflectance method on well AL 25 and spread direction of coal seam at the research area.Methods of research are descriptive and analysis. Based on these methods, done the stage of the analysis and interpretation with data supporting are stratigraphical data and laboratory data. Activities performed such as geological mapping, maceral analysis with vitrinite reflectance methods and coal quality interpretation on well AL 25. The software used to support this undergraduate thesis are the Arcgis ,Autocad X 5 and Corel Draw. In Undergraduate Thesis, the author has divided into five phases, such as lithology description, cropline withdrawal based on strike and dip, maceral analysis, coal quality interpretation and results correlation of maceral analysis, rank and coal quality on the well AL 25.Based on the result of analysis data, it can be interpreted that lithology at the research area are sandstones, siltstone, claystone and thin layer of coal. The direction of seam coal ( cropline ) at the research area is southeast - northwest based on strike / dip. The results of the maceral analysis for each seam produce rank between Lignite to High Volatile bituminous B, whereas the results of the quality analysis for each seam produces a caloric value ranging from 12040.35 to 13786.69 Btu/lb or ranged from High Volatile Bituminous C to High Volatile Bituminous B. Based on the result of maceral analysis, rank and coal quality, it can be concluded that there are a mutual relation between maceral, rank and coal quality. The mutual relation is when the high percentage value of vitrinite reflectance so that value of coal calorie is good too.
PENENTUAN TIPE ALTERASI BERDASARKAN ANALISIS PETROGRAFI, MINERAGRAFI, DAN GEOKIMIA PADA DAERAH KASIMBAR, KABUPATEN PARIGI MOUTONG, PROVINSI SULAWESI TENGAH Salamah, Ainul Fatayatis; Aribowo, Yoga; Widiarso, Dian Agus; Ali, Rinal Khaidar
Geological Engineering E-Journal Vol 6, No 1 (2014): Volume 6, Nomor 1, Tahun 2014
Publisher : Geological Engineering E-Journal

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Abstract

Hydrothermal alteration is a complex process, because it involves a change in mineralogy, chemistry and texture resulting from the interaction of hydrothermal solutions with rocks in its path on certain physico-chemical conditions (Pirajno, 1992). Hydrothermal processes in certain circumstances will result a collection of certain minerals known as the set of mineral or mineral assemblage (Guilbert and Park, 1986). One evidence of hydrothermal alteration is the appearance of veins that had level of metal minerals and it is also a change on the rock side, as found in Kasimbar District, Moutong Parigi Regency, Central Sulawesi province. In the area discovered the existence of gold in the alluvium sediments that are the result of weathering schist and quartz veining. Gold is found in alluvium sediments are secondary gold or placer gold. From the research that has been done, found gold in quartz veins trapped on phyllite rocks. This study was conducted to determine the lithology of the region, the study based on petrographic analysis, knowing the characteristics of the rock alteration found in the study area based on petrographic analysis mineragraphy, knowing the type of alteration that develops in the area of research, knowing mineralization contained in the study area. Research in Kasimbar District, Parigi Moutong Regency, Central Sulawesi Province was conducted by analyzing rock samples taken from the area. Analysis is conducted with the petrographic analysis, mineragraphy, lithology and geochemistry of the units located in the area.Based on the results of petrographic thin section analysis of rock samples, lithology contained in Kasimbar District, Parigi Moutong Regency, Central Sulawesi Province is phyllite, granite and gneiss. Alteration characteristics of the study area is known of the characteristics quartz veins, alteration minerals characteristics and  metal minerals characteristics. Quartz veins in the study area was divided into two, namely quartz veins in granite and quartz veins in metamorphic rocks (parallel and cut foliation). Characteristic alteration minerals contained in the study area is chlorite, sericite, biotite, epidote and quartz. Mineralization characteristics of the region, is study of sulphide minerals such as pyrite, bornite, and enargite; iron oxide minerals such as magnetite and hematite and the mineral element in the form of native gold (Au). Type of alteration is developed in the research area of prophylitic alteration, potassic alteration, silicification alteration, and carbonization alteration. Type of mineral deposits research areas is high sulfidation epithermal deposits.
GEOLOGI, ALTERASI HIDROTERMAL, DAN MINERALISASI DAERAH ONTO DAN SEKITARNYA, KECAMATAN HU’U, KABUPATEN DOMPU, PROVINSI NUSA TENGGARA BARAT Febriansyah, Alif; Aribowo, Yoga; Widiarso, Dian Agus
Geological Engineering E-Journal Vol 6, No 2 (2014): Wisuda Periode Juli - Oktober 2014
Publisher : Program Studi Teknik Geologi, Fakultas Teknik, Universitas Diponegoro

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Abstract

The use of metallic minerals as raw materials is increasing. Therefore, Indonesia needs to improve metallic mineral reserves for the needs of the country and internationally to explore maximally. This can be done because some parts of Indonesia has huge reserves of metallic minerals.. This research purposed to learn about geological condition of research area involve morphology, lithology, and structure geology, determine alteration zone, and learn distribution of Copper (Cu) that contained in research area.Methodology used in this research is survey method and analysis method. Survey methos by doing surface geological mapping. Analytical method by doing petrology analyisis, petrography analysis, mineragraphy analysis, ASD analysis (Analytical Spectral Device) and sturcture geology analysis.Geomorphology of Onto and the surrounding divided into two units are volcanic very steep hill unit and volcanic steep hill unit. Lithology of research area from older  to younger are tuff, volcanic breccia and breached by porphyrytic andesite. Structure geology in research area in the form of alignment pattern by Dem Map (Digital Elevation Model) in period I direction of structure is west-east and northwest-southeast, whereas in period III direction is north-south. The alteration zone of research area are divided into advanced argillic zone associated with dickite, alunite, and kaolinite minerals; argllic zone associated with kaolinite, palygorskite, and siderite minerals; and intermediet argillic associated with palygorskite and Chlorite minerals. Mineralization of research area is in the form of stockwork and disseminated whick mineralized by pyrite and chalcopyrite as ore mineral. Type of mineralization deposition in research area is Porphyry depoosition type. The value levels of Copper in research area are potential with 1132,79 ppm in tuff unit STA. 33, STA. 35 with value levels of copper is 130,01 ppm, STA. 55 is 390,37 ppm, STA. 56 is 499,9 ppm and STA. 73 is 288,95 ppm.