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All Journal Jurnal Pendidikan dan Pembelajaran SOSIOLOGI IJOG : Indonesian Journal on Geoscience Medical Journal of Indonesia Jurnal Pendidikan Matematika Berkala Ilmu Kesehatan Kulit dan Kelamin Jurnal Pengabdian Kepada Masyarakat Universitas Bangka Belitung Al-Ijtima`i: International Journal of Government and Social Science EDU-MAT: Jurnal Pendidikan Matematika As-syifaa Jurnal Farmasi Jukung (Jurnal Teknik Lingkungan) Syifa' MEDIKA: Jurnal Kedokteran dan Kesehatan Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) Inovasi: Jurnal Ilmiah Ilmu Manajemen Journal Agriculture Sciences JENIUS (Jurnal Ilmiah Manajemen Sumber Daya Manusia) Budapest International Research and Critics Institute-Journal (BIRCI-Journal): Humanities and Social Sciences Nusantara Science and Technology Proceedings
Iskandar Zulkarnain
Division of Tropical and Infectious Diseases, Department of Internal Medicine, Faculty of Medicine, Universitas Indonesia, Jakarta.
Religion Agriculture, Biological Sciences & Forestry Arts Humanities Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Decision Sciences, Operations Research & Management Earth & Planetary Sciences Economics, Econometrics & Finance Education Engineering Environmental Science Health Professions Immunology & microbiology Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Mathematics Medicine & Pharmacology Public Health Social Sciences Other

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Journal : IJOG : Indonesian Journal on Geoscience

 1 
Geochemical Signature of Mesozoic Volcanic and Granitic Rocks in Madina Regency Area, North Sumatra, Indonesia, and its Tectonic Implication Zulkarnain, Iskandar
Indonesian Journal on Geoscience Vol 4, No 2 (2009)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (894.092 KB) | DOI: 10.17014/ijog.v4i2.74

Abstract

http://dx.doi.org/10.17014/ijog.vol4no2.20094Five samples consisting of two Permian-Triassic basalts, two Triassic-Jurassic granitic rocks, and a Miocene andesite were collected from the Madina Regency area in North Sumatra that is regionally situated on the West Sumatra Block. Previous authors have proposed three different scenarios for the geological setting of West Sumatra Permian Plutonic-Volcanic Belt, namely an island-arc, subduction related continental margin arc, and continental break-up. Petrographic analysis of the Mesozoic basaltic samples indicates that they are island-arcs in origin; however their trace element spider diagram patterns (Rock/MORB ratio) also show the character of back-arc marginal basin, besides the island-arc. Furthermore, their REE spider diagram patterns (Rock/ Chondrite ratio) clearly reveal that they were actually generated in a back-arc marginal basin tectonic setting. Meanwhile, the two Mesozoic granitic rocks and the Miocene andesite reflect the character of an active continental margin. Their spider diagram patterns show a significant enrichment on incompat- ible elements, usually derived from fluids of the subducted slab beneath the subduction zone. The high enrichment on Th makes their plots on Ta/Yb versus Th/Yb diagram are shifted to outside the active continental margin field. Although the volcanic-plutonic products represent different ages, their La/Ce ratio leads to a probability that they have been derived from the same magma sources. This study offers another different scenario for the geological setting of West Sumatra Permian Plutonic-Volcanic Belt, where the magmatic activities started in a back-arc marginal basin tectonic setting during the Permian-Triassic time and changed to an active continental margin during Triassic to Miocene. The data are collected through petrographic and chemical analyses for major, trace, and REE includ- ing literature studies.  
Petrogenesis batuan vulkanik daerah tambang emas Lebong Tandai, Provinsi Bengkulu, berdasarkan karakter geokimianya ZulkarnaIn, Iskandar
Indonesian Journal on Geoscience Vol 3, No 2 (2008)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (941.7 KB) | DOI: 10.17014/ijog.v3i2.48

Abstract

http://dx.doi.org/10.17014/ijog.vol3no2.20081Lebong Tandai is a village in the Napal Putih Sub-regency, North Bengkulu Regency, that can be accessed only through the local people train called “molek”. The area is well known as a gold mine since the Dutch time. Volcanic rocks in the area belong to the Hulusimpang Formation that are dominated by andesitic rocks with small amount of dacite and basalt. They show an affinity as a transition between calc-alkaline and tholeiite. Its trace elements and REE patterns show that they are derived from “magma one”, one of the two magma sources producing volcanic rocks in Bengkulu. “Magma one” is derived from a magma source with adakitic composition due to the most primitive sample among the “magma one” samples. The Lebong Tandai magma activity has occurred since more than 30 million years ago in a back-arc side tectonical environment, and they were enriched on incompatible elements during an upper crust penetration. The occurrence of gold mineralization in this area indicates that the “magma one” is a gold bearing mineralized magma in this region. It seems to be reasonable when it is corresponded with an investigation result reported from the Phillippine that adakitic rocks contain higher gold concentration than calc-alkaline rocks. This paper is written using a geochemical approach based on major elements, trace elements and rare earth elements (REE) that are plotted into general and specific classifications in a petrological discussion.  
Geochemical Evidence of Island-Arc Origin for Sumatra Island; A New Perspective based on Volcanic Rocks in Lampung Province, Indonesia Zulkarnain, Iskandar
Indonesian Journal on Geoscience Vol 6, No 4 (2011)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2460.316 KB) | DOI: 10.17014/ijog.v6i4.128

Abstract

DOI: 10.17014/ijog.v6i4.128Since decades, Sumatra Island is considered as the Eurasia continental margin where the Indian Ocean plate has been subducted oblique beneath the continental plate of Sumatra. But, the occurrences of volcanic rocks in almost all areas of Lampung Province in the southernmost of Sumatra Island, as the presence of the Quaternary Tanggamus Volcano in the western part of the province together with the Quaternary Rajabasa Volcano in the eastern area cannot be justified using the consideration. Spider diagrams of trace and rare earth elements of volcanic rocks from the western and eastern areas of the province reveal that the rocks come from three different tectonic settings, namely island-arc, active continental margin (ACM), and intra continental plate. All basalt and one dacite of western volcanic rocks show a character of island-arc origin, while the eastern volcanic rocks are reflecting characters of ACM and intra continental plate. Plot of the rocks in the diagram of Ta/Yb versus Ce/P and in Ta/Yb versus Th/Yb confirmed the tectonic environments and specifically classify the intra continental plate into Within Plate Volcanic Zone (WPVZ). The island-arc group is characterized by Ta/Yb ratio of less than 2.0 and Ce/P less than 1.8. The ACM group is recognized having Ta/Yb ratio between 2 and 4 with Ce/P more 1.8, while the WPVZ group is defined as a group having Ta/Yb more than 6 and Ce/P more than 1.0. The result indicates that the western part of Sumatra is an island-arc fragment and the eastern part belongs to the Eurasia continental margin. The concentration of volcanics having ACM character from areas around the Sumatra Fault System to the east indicates that the collision zone between the Sumatra island-arc fragments with the Eurasia continental margin is probably located along the SFS. More statistical data is still needed from other Sumatra volcanics to confirm this conclusion.
Scale Prevention Technique to Minimized Scaling on Re-Injection Pipes in Dieng Geothermal Field, Central Java Province, Indonesia Agustinus, Eko Tri Sumarnadi; Syafri, Ildrem; Rosana, Mega Fatimah; Zulkarnain, Iskandar
Indonesian Journal on Geoscience Vol 5, No 2 (2018)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.5.2.129-136

Abstract

DOI: 10.17014/ijog.5.2.129-136Dieng geothermal field including its volcanic geothermal system is dominated by hot water. Brine water is characterized by high salinity, content of chloride (Cl-), amorphous silica (SiO2), Na+, and K+. The condition of brine water has potential for the formation of amorphous silica scale in the re-injection pipeline which is one of the obstacle in the electrical energy production. The scale prevention on re-injection pipes was performed with non-acid re-injection system. Nevertheless, the scale formed in the re-injection pipe is still relatively thick due to the non-optimal sludge. This research is focused in optimizing the deposition of sludge. The research aim is to apply scale prevention technique on re-injection pipeline by involving engineering technology. The study was conducted through laboratory experiments with factorial design method 23 (two levels of three factors). Those three factors are pH, concentrations of coagulants and flocculants concentrations which act as the independent variables. The indicator is the volume of sludge deposition and turbidity of brine water which act as the dependent variables. The result showed that the most significant factor is pH, whereas the concentrations of coagulant and flocculant are preserved to accelerate and stabilize the sludge deposition. The optimal condition is achieved at the level of pH 8, the concentration of 10 ppm coagulant (PAC), and 1 ppm flocculants (Polyamide). These parameters are then used for the preparation of scaling process technology on the prevention of re-injection pipeline by adding some equipments on settling ponds. Therefore, in addition to reduce environmental degradation, it also produces sludge that has potential to be used as raw materials for other industries.
Co-Authors Afrian, Chandra Agus Haryanto Agustini Rahmawati, Agustini Ahmad Atiq Aminullah Aminullah, Aminullah Asmahani Thohiroh, Asmahani Asmara, Sakhyan Bagus Haryo Kusumaputra, Bagus Haryo Bustami Rahman Dewi, Winda Evina Eko Tri Sumarnadi Agustinus Haryantini, Haryantini Hasmeinah, Hasmeinah Hendarto Hendarto I Gusti Bagus Wiksuana Ildrem Syafri Ismadi Raharjo, Ismadi Istanto, Kelik Julianti Gunawan Kinanti Prabawaningrum, Kinanti KURNIA KURNIA, KURNIA Kurniati Kurniati Lita Setyowatie, Lita M. Yulianto Listiawan Mega Fatimah Rosana Michael Jeffri Sinabutar Mulyadi Mulyadi Noor Amalia Sari, Noor Nurdin Laugu Pedia Primadiarti, Pedia R.H.H. Nelwan Rachman, Firdaus Rahmadewi Rahmadewi Ramadhani, Tiara Ririn Ririn Rospala Hanisah Yukti Sari Siska Natsir, Siska Soraya Djamilah, Soraya Suhartono, H. Irwan Toruan, Rachel Mia Lorenza Lumban Udin Hasanudin Victor G Simanjunta W, Hestu Nugroho