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MIKROFASIES BATUGAMPING FORMASI BULU DAN KUALITAS BAHAN BAKU SEMEN, PADA LAPANGAN GUNUNG “PAYUNG”, KECAMATAN BOGOREJO, KABUPATEN BLORA JAWA TENGAH Fadhlillah, Ajidityo Putro; 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

Bulu Formation is one of formation which is sedimented at Tertiary age in The North East Java Basin. Bulu Formation has a lithological composition of limestones with kalkarenit. Bulu Formation is located in Gandu village, Tahunan Village, and the surrounding areas, District Bogorejo, Blora, Central Java, with a particular study on the "Gunung Payung".The study aimed to determine microfasies, facies zone, the relative age, and standart of quality limestone as materials cement on data petrographic, paleontologist, and chemical analysis of limestone samples in the study area. Development of Limestone Bulu Formation Unit microfacies is Bioclast Red Algae Packstone, Bioclast Large Foram Grainstone, Bioclast Large Foram Packstone, Bioclast Planktonic Foram Packstone, Bioclast Grainstone with dolomitation, Planktonic Forams Grainstone, Planktonic Wackstone, Peloidal Wackestone, Packstone with dolomitation, Bioclast Wackstone with microspar, Bioclast Planktonic Foram Wackstone, Bioclast Wackstone with dolomitation, Bioclast Packstone with dolomitation, and Dolomite limestone.Based on the analysis microfacies and foraminifera on the areas of research, there are 3 types of facies zoning based on the model of Wilson (1975), namely: FZ 5 Platform - Margin Reefs, Marine Open 7 FZ, FZ 8 Platform and Interior - Restricted to the age of rocks between N9 to N12 is the Middle Miocene. From the chemical analysis, the potential limestones in the study area can be used as raw material for cement and relationships microfacies analysis and chemical analysis showed that the pitch "Gunung Payung" has a great potential in terms of good quality which is spread of West to East direction. The west area of “Gunung Payung” has better quality of limestone as a raw material for cement than east area.
IDENTIFIKASI KARAKTERISTIK ALTERASI HIDROTERMAL DAN MINERALISASI ENDAPAN EMAS EPITERMAL DAERAH PROSPEK RAMADA, KECAMATAN CIMANGGU, KABUPATEN PANDEGLANG, PROVINSI BANTEN Chrishartantyo, Gregorius Agung; Aribowo, Yoga; Widiarso, Dian Agus; Kurniawan, Andi
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

Cibaliung Gold Project area is one of the largest primary gold deposits mineralization prospect areas in the western part of Java island which is controlled by PT. Antam (Persero) Tbk.. The research area is part of the Cibaliung Gold Project area called Ramada Prospect. Administratively, Ramada Prospect located in Cimanggu Subdistrict, Pandeglang District, Banten Province. Research conducted aimed to determine the geological condition, characteristics of hydrothermal alteration and gold deposition mineralization, as well as predicting the environmental conditions of hydrothermal constituent.Research conducted with descriptive and qualitative analysis approach. The research method used consists of literature study, field observation, and laboratory test. In the literature study methods conducted assessment of the theoretical basis and previous research. Field survey methods consists of geological mapping, mapping of alteration and mineralization, as well as description and identification of rock core drilling results. In the laboratory test method conducted descriptions and identifications of petrographic, mineragraphy, and X-Ray Diffraction (XRD) to some rock samples and veins, as well as analysis of geological structure stereographic method. The research was also supported by secondary data such as AAS (Atomic Absorption Spectrometry) test results.Lithology of research area consists of tuff rock units, pyroclastic breccia rock units, and andesite lava flow rock units. Pyroclastic breccias rock units and andesite lava flow rock units are interpreted as pre-mineralization rocks, whereas tuff rock units are interpreted as post-mineralization rocks. Based on the analysis of geological structure there is interpreted strike-slip fault has affected geological conditions of the research area. Hydrothermal alteration in the research area can be divided into alteration facies of kaolinite-smectite-chlorite±quartz±carbonate-pyrite replacement-infill strong intensity and alteration facies of chlorite±epidote±sericite±quartz±carbonate-pyrite replacement-infill moderate-strong intensity. Gold deposition mineralization (Au) in the research area predominantly formed on quartz±carbonate veins. The presence of gold associated with silver (Ag) and pyrite (FeS2). The main prospect gold deposits mineralization in the research area contained in "Ramada" veins. Hydrothermal environment in research area interpreted as a low sulfidation epithermal deposition system that developed in the ancient depths of 120 m - 340 m with temperatures around 175 °C - 225 °C.
GEOLOGI, ALTERASI HIDROTERMAL DAN MINERALISASI DAERAH CIURUG DAN SEKITARNYA, KECAMATAN NANGGUNG, KABUPATEN BOGOR, PROVINSI JAWA BARAT Agus Binsar, Mohammad Tommy; 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 existence of metallic minerals in nature is closely related to geological conditions and hydrothermal alteration. hydrothermal alteration and mineralization occur due to hydrothermal solutions that change the physical and chemical properties of rocks and carrying metal elements which will be deposited on rock porosity and permeability have. hydrothermal alteration will make a special characteristic as an altered mineral association. Study of this alteration zone and mineralization will help us to make a plan for metal resources exploration. The purpose of this study was to determine the geological conditions study area include the morphology , lithology , structural geology , hydrothermal alteration zones , mineralization and determine the relationship between geology , hydrothermal alteration , and mineralization.Methods of research is using survey and analysis methods. Survey conducted by the method of data that collected in the field in the form of surface geological   mapping.   The   analysis   method     was     analysis    of    petrology, petrography, X-ray (XRD), and geological structure.Regional geomorphology of Ciurug Area classification based on Van Zuidam (1983) is divided into two units , namely units steep hilly volcanic landforms and volcanic landform units is very steep mountains. Lithology of the study area consists of older to younger andesite breccia , andesite lava, lapilli tuff , tuff , and andesite intrusion . Geological structure of the study area has a north-south direction . Hydrothermal alteration zones are present in the study area is the zone of argillic ( Illit - Kaolin ) , propylitic zone ( Smectite - Chlorite ) , and silicified zones ( Silica - Quartz ) . Mineralization in the area of research in the form of quartz veins and disseminated pyrite and chalcopyrite mineralization as ore deposits . Type of sediment deposition area of research   is  a   low   sulfidation epithermal type.
Penentuan Potensi Sumberdaya Batu Gamping Sebagai Bahan Baku Semen Daerah Gandu Dan Sekitarnya, Kecamatan Bogorejo, Kabupaten Blora, Jawa Tengah Widiarso, Dian Agus; Kusuma, Istiqomah Ari; Fadhlillah, Ajiditya Putro
TEKNIK Vol 38, No 2 (2017): (Desember 2017)
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (802.713 KB) | DOI: 10.14710/teknik.v38i2.13213

Abstract

Kebutuhan pembangunan infrastruktur selalu meningkat seiring dengan pertumbuhan penduduk. Industri konstruksi membutuhkan batugamping yang merupakan bahan pembuatan semen untuk pondasi konstruksi bangunan. Salah satu daerah yang memiliki potensi batu gamping adalah daerah Gandu, Kecamatan Bogorejo, Blora, Jawa Tengah. Penelitian ini bertujuan untuk melakukan eksplorasi potensi batu gamping di daerah Gandu. Pemetaan geologi dilakukan untuk menentukan litologi utama daerah penelitian dan distribusinya. Analisis kualitas batugamping juga dilakukan dalam penelitan ini, dengan  mengkaji komposisi kimia batugamping. Diharapkan hasil penelitian ini dapat digunakan sebagai dasar pemanfaatan batugamping untuk kebutuhan industri semen. Hasil penelitian menunjukkan bahwa stratigrafi regional area penelitian terdiri dari empat satuan batuan, yaitu batulempung karbonan, batugamping, kristalin batupasir kuarsa, dan batugamping. Hasil penelitian juga menunjukkan bahwa batugamping dari daerah Gandu memiliki unsur CaO cukup besar dan unsur Mg sedikit, walaupun di beberapa tempat banyak ditemukan unsur Mg. Perbandingan hasil analisis komposisi kimia dan standar bahan baku semen menunjukkan bahwa kapur di daerah Gandu memenuhi kriteria bahan baku semen
POTENSI AIR TANAH DAERAH KAMPUS UNDIP TEMBALANG Dian Agus, Widiarso; Henarno, Pudjihardjo; Wahyu, Prabowo
TEKNIK Volume 33, Nomor 2, Tahun 2012
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (476.406 KB) | DOI: 10.14710/teknik.v33i2.4381

Abstract

Provision of clean water in an area need both now and future dating. Provision of clean water can be done byutilizing the potential of existing surface water and ground water. Geoelectric method is widely use forgroundwater investigation. Geoelectric observations at 10 observation points can generate Aquifer Zone Map ofTembalang and surroinding areas.
Studi Kerentanan Air Tanah Terhadap Kontaminan Menggunakan Metode Drastic di Kota Pekalongan Putranto, Thomas Triadi; Widiarso, Dian Agus; Yuslihanu, Fatir
TEKNIK Vol 37, No 1 (2016): (Juli 2016)
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (559.327 KB) | DOI: 10.14710/teknik.v37i1.9637

Abstract

Kota Pekalongan berada di Pulau Jawa bagian Utara. Jumlah penduduk kota pekalongan setiap tahunnya mengalami peningkatan. Tahun 2008 jumlah penduduk Kota Pekalongan sebanyak 271.990 jiwa kemudian menjadi 290.347 di Tahun 2012.. Untuk memenuhi kebutuhan air, peduduk Kota Pekalongan menggunakan sumur gali yang menyadap air dari akuifer bebas atau akuifer dangkal. Air tanah bebas sangat rentan terhadap pencemaran akibat pengaruh letaknya yang dangkal dan aktivitas manusia. Oleh sebab itu diperlukan suatu kajian mengenai kerentanan air tanah terhadap kontaminan. Analisis dilakukan denganmenggunakan metode DRASTIC. Metode ini merupakan metode pombobotan berdasarkan beberapa parameter, yaitu: kedalaman muka air tanah (D), jumlah area recharge (R), litologi akuifer (A), jenis media tanah (S), topografi (T), jenis media zona tak jenuh air (I), dan konduktivitas hidrolika (C). Berdasarkan hasil analisis DRASTIC, terdapat tiga tingkat kerentanan yaitu: daerah tingkat kerentanan sedang dengan nilai DRASTIC Indeks (DI) 101-140, daerah tingkat kerentanan tinggi dengan nilai DI 141-180, dan daerah tingkat kerentanan sangat tinggi dengan nilai DI >180.[An Assessment of Groundwater Vulnerability of Contaminant Using DRASTIC Method in Pekalongan City] Pekalongan city which located on the north of Java Island is growing fast, in particular in the population growth. In 2008, total population in Pekalongan city was 271.990 inhabitants increased then up to 290.347 inhabitants in 2012. To fill the water necessary, people in Pekalongan city are using dug wells which are abstracted groundwater from the unconfined aquifer or shallow aquifer. Shallow groundwater can be vulnerabe which are influenced by surface and human activities. Thus, it requires an assessment of the groundwater vulnerability and risk of contaminant. It was analyzed by DRASTIC method. The DRASTIC method is applied by using weighted of some parameters, i.e.: groundwater Depth (D), amount of Recharge (R), Aquifer type (A), Soil type (S), topography (T), Impact of unsatuated zone (I), and hydraulic Conductivity (C). DRASTIC Index (DI) results in three vulnerability levels which are medium with DI 101-140, high with DI around 141-180 and above 180 for high vulnerable of contaminant.
HUBUNGAN KETERDAPATAN BATUAN KALK SILIKAT PADA ENDAPAN PORFIRI CU-AU BATU HIJAU, SUMBAWA, NUSA TENGGARA BARAT Widiarso, Dian Agus; Suprapto, Rachdian Eko; Winarno, Tri; Rakhman, Arie Noor
Jurnal Teknologi Vol 12 No 2 (2019): Jurnal Teknologi
Publisher : Jurnal Teknologi, Fakultas Teknologi Industri, Institut Sains & Teknologi AKPRIND Yogyakarta

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Abstract

Potensi sumber daya tembaga (Cu) dan Emas (Au) di Area Batu Hijau, Nusa Tenggara barat sangat melimpah. Batuan di Batu Hijau memiliki sistem endapan mineral berjenis porfiri Cu-Au dan potensi endapan penyerta berjenis skarn. Keterdapatan skarn ditunjukkan oleh interval batuan kalk silikat pada hasil pemboran batuan inti di Batu Hijau. Metode penelitian yang digunakan dalam penelitian adalah deskripsi batuan kalk silikat (pendataan megaskopis batuan inti dan analisis petrografi) dan analisis data sekunder fisikokimia. Batuan kalk silikat area penelitian terdiri dari variasi hornfels dan skarn dengan komposisi mineral kalk silikat, mineral sulfida dan mineral oksida. Secara spasial, batuan kalk silikat berada di zona proksimal endapan porfiri, persebaran setempat akibat kontrol struktur geologi, variasi kedalaman terdangkal batuan kalk silikat di area Barat 147,93 m dan di area Timur 205 m dengan interval terdalam di area barat -540,4 m dan area Timur -571,84 m. Secara genetik, skarnifikasi progradasi dan retrogradasi ekuivalen dengan zona alterasi potasik-filik (320° -280°C) dan fase awal profilitik (~280°C) dari zona alterasi endapan porfiri. Batuan kalk silikat memiliki korelasi spasial dan genetik dengan endapan porfiri Cu-Au.
Subsurface Structure and Fluid Flow Analysis Using Geophysical Methods in the Geothermal Manifestation Area of Paguyangan, Brebes, Central Java Setyawan, Agus; Triahadini, Agnis; Yuliananto, Yayan; Aribowo, Yoga; Widiarso, Dian Agus
International Journal of Renewable Energy Development Vol 5, No 3 (2016): October 2016
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.5.3.171-177

Abstract

The indication of an active geothermal system is shown by the presence of surface manifestations such as the hot spring in Kedungoleng, Paguyangan, Brebes, Central Java. The temperature of the largest hot spring reaches 74o C and there is an assumption that this is an outflow of Mount Slamet geothermal system. DC-resistivity, Spontaneous Potential (SP) and Shallow Surface Temperature surveys were conducted to determine the subsurface structure as well as its correlation with the distribution of thermal fluid flow and shallow surface temperature. The subsurface resistivity has been investigated using 5 points of the Schlumberger configuration with 400 m separation for each point. For the fluid and temperature pattern, a measurement using 15 m interval in 3 lines of conducting fixed electrode configuration has been carried out, along with a 75 cm of depth of temperature measurement around the manifestation area. The thermal fluid is assumed by the low resistivity of 0.756 to 6.91Ωm and this indicates sandstone that has permeable characteristic. The fluid flows in two layers of Sandstone at more than 10 meter from surface of the first layer. Accordingly, the SP values have a range between -11- 11 mV and a depth interval of 13.42- 28.75 m and the distribution of temperature is between 24o-70oC at a tilting range of 46.06o-12.60o. Hence it can be inferred that the thermal fluid moves in the Northwest direction and is controlled by a fault structure stretching from Northwest to Southeast.Article History: Received Feb 3, 2016; Received in revised form July 11, 2016; Accepted August 13, 2016; Available onlineHow to Cite This Article: Setyawan, A., Triahadini, A., Yuliananto, Y., Aribowo, Y., and Widiarso, D.A. (2016) Subsurface Structure and Fluid Flow Analyses Using Geophysical Methods in Geothermal Manifestation Area of Paguyangan, Brebes, Central Java. Int. Journal of Renewable Energy Development, 5(3), 171-177.http://dx.doi.org/10.14710/ijred.5.3.171-177
PENGARUH STRUKTUR DAN TEKTONIK DALAM PREDIKSI POTENSI COALBED METHANE SEAM PANGADANG-A, DI LAPANGAN “DIPA”, CEKUNGAN SUMATERA SELATAN, KABUPATEN MUSI BANYUASIN, PROVINSI SUMATERA SELATAN Ragil Pratiwi; Hadi Nugroho; Dian Agus Widiarso; Rana Lesmana
Geological Engineering E-Journal Vol 5, No 2 (2013): Volume 5, Nomor 2, Tahun 2013
Publisher : Program Studi Teknik Geologi, Fakultas Teknik, Universitas Diponegoro

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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. 
GEOLOGI, ALTERASI HIDROTERMAL, DAN MINERALISASI DAERAH ONTO DAN SEKITARNYA, KECAMATAN HU’U, KABUPATEN DOMPU, PROVINSI NUSA TENGGARA BARAT Alif Febriansyah; Yoga Aribowo; Dian Agus Widiarso
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.