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Contact Name
Sri Mulyaningsih
Contact Email
sri_m@akprind.ac.id
Phone
+6222-7213793
Journal Mail Official
ijog@bgl.esdm.go.id
Editorial Address
Jl. Diponegoro No. 57 Bandung
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INDONESIA
Indonesian Journal on Geoscience
ISSN : 23559314     EISSN : 23559306     DOI : https://doi.org/10.17014/ijog.3.2.77-94
Core Subject : Science,
The spirit to improve the journal to be more credible is increasing, and in 2012 it invited earth scientists in East and Southeast Asia as well as some western countries to join the journal for the editor positions in the Indonesia Journal of Geology. This is also to realize our present goal to internationalize the journal, The Indonesian Journal on Geoscience, which is open for papers of geology, geophysics, geochemistry, geodetics, geography, and soil science. This new born journal is expected to be published three times a year. As an international publication, of course it must all be written in an international language, in this case English. This adds difficulties to the effort to obtain good papers in English to publish although the credit points that an author will get are much higher. This Journal publishes 3 numbers per year at least 15 articles. It is a challenge for the management of the journal to remain survive and at the same time continuously maintain its quality and credibility in spite of those various constraints. Fortunately, this effort is strongly supported by the Geological Agency of Indonesia, as the publisher and which financially bear the journal. Last but not least the journal is also managed by senior geologist of various subdisciplines from various countries who are responsible for its quality.
Articles 323 Documents
Karakteristik batubara di Cekungan Bengkulu Heryanto, Rachmat; Suyoko, Suyoko
Indonesian Journal on Geoscience Vol 2, No 4 (2007)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.2.4.247-259

Abstract

http://dx.doi.org/10.17014/ijog.vol2no4.20075Bengkulu Basin is known as a fore arc basin, which located in the southwestern part of Sumatera Island. Bengkulu Basin is occupied by Oligo-Miocene siliciclastic, coal, and carbonate sediments. Coal, one of alternative energies which can substitute hydrocarbon, is found within the sedimentary rocks of the Middle to Upper Miocene Lemau Formation as observed in Ketaun, Bengkulu, and Seluma areas. The thickness of the coal seams in the Ketaun area ranges from 100 to 200 cm, whereas in the Bengkulu area it varies between 100 to 350 cm, and in Seluma area up to 450 cm. Megascopically, coal seams in the Ketaun area are black in colour, dull to dull banded, with brownish black in streak, whereas in the Bengkulu and Seluma areas show a black colour, bright banded, and black streak. The mean of vitrinite reflectant value (Rv) of coal seam in the Ketaun area ranges from 0.41 to 0.49%, whereas in the Bengkulu and Seluma area it varies from 0.44 to 1.12%. The higher vitrinite reflectance of the Bengkulu and Seluma coals is probably due to the influence of andesitic sill intrusion. In general, the coal in the Ketaun area was deposited in an environment of relatively more to marine direction or limited influx clastic marsh or lower delta plain, where the tree density decreased. However, the coal in the Bengkulu and Seluma areas occurred in an environment which was relatively more to land direction or telmatic, or upper delta plain or wet forest swamp, where the tree density increased.  
Amblesan di daerah Porong, Kabupaten Sidoarjo, Jawa Timur Sudarsono, Untung; Sudjarwo, Indra Budi
Indonesian Journal on Geoscience Vol 3, No 1 (2008)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.3.1.1-9

Abstract

http://dx.doi.org/10.17014/ijog.vol3no1.20081On 29th May 2006, there was a huge mud outpouring in the Porong Subregency, Regency of Sidoarjo, East Jawa and for one year, it had flooded the area of more than 5 km2 including Porong, Tanggulangin and Jabon Sub-regencies. The mud known as Lumpur Sidoarjo. The impact of the mud outpouring was the presence of a subsidence around the main outpouring for the width of 6.3 km2 in ellipse stretching to the north. The subsidence area covered Tanggulangin Sub-regency: Kedungbendo Village, Porong Sub-regency: Siring, Jatirejo, Mindi, and Renokenongo Villages, and Jabon Sub-regency: Pejarakan and Besuki Villages. The rate of the subsidence is ap- proximately 2 cm/day.  
Batubara Formasi Warukin di daerah Sampit dan sekitarnya, Kalimantan Tengah Kusnama, Kusnama
Indonesian Journal on Geoscience Vol 3, No 1 (2008)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.3.1.11-22

Abstract

http://dx.doi.org/10.17014/ijog.vol3no1.20082The Warukin Formation in Sampit area, occupying the Barito Basin, was conformably deposited on top of the Berai Formation, but unconformably lies on the Tanjung Formation, Undifferentiated Metamorphic Rocks and Sepauk Granitic Rock. The formation consists of sandstone, interbedded claystone-mudstone, conglomerate and intercalations of coal, having Early-Late Miocene in age. Coal of the Warukin Formation at the Sampit area occurs within sandstone and interbedded claystone-mudstone facies. Two main seams, A and B, was deposited within sandstone and interbedded claystone-mudstone facies respectively. Generally, the coal is bright banded with partly dull lithotypes; brownish black in colour and it has a medium to light in weight. Physically, the coal recognized in two seams, is generally banded with brittle to friable in hardness; and has partings of claystone and mudstone. The thickness of the coal deposit ranges from 80 cm to 200 cm. On the basis of calorific value and lithotype, and also ash, moisture, and sulphur contents, the coal includes to subbituminous C - A rank. The coal was deposited in a wet-forest swamp occupied by high plants and shrubs.    
Petrologi - geokimia batuan Gunung Api Tampomas dan sekitarnya Dirk, Mesker H.
Indonesian Journal on Geoscience Vol 3, No 1 (2008)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.3.1.23-35

Abstract

http://dx.doi.org/10.17014/ijog.vol3no1.20083Volcanic rocks of Mount Tampomas and its surroundings belong to low–K, calc–alkaline, and high–K series of basalt, basaltic andesite, and andesite suites containing 48.59 – 60.49 wt% of SiO and 0.31-1.67 wt% of K O. The rocks are typically formed in an island arc environment characterized by the high content of Al O (16.47 – 21.76 wt%), low to moderate content of MgO (2.37 – 8.84 wt%), low content of both titanium TiO (< 1 wt%) and high field strength elements (HFSEs), negative anomaly of Nb relative to K and La. The light rare earth elements (LREEs) enrichment but low abundances of heavy rare earth elements (HREEs) indicate fractionation process. The parent magma was an extensive removal of olivine and clino-pyroxene, plagioclase, apatite, and titanoferrousmagnetite from a basalt olivine magma of N-MORB character that was firstly enriched by LILEs such as Ba, Rb, Th, K, and LREE (La). The differentiation lasted, and the magma became water undersaturated at the crystallization phase of hornblende. The high content of incompatible elements such as Ba, Th, La, Ce, may indicate contamination by liquid derived from the subducted slab.   
Gumuk gunung api purba bawah laut di Tawangsari - Jomboran, Sukoharjo - Wonogiri, Jawa Tengah Hartono, Gendoet; Sudrajat, Adjat; Syafri, Ildrem
Indonesian Journal on Geoscience Vol 3, No 1 (2008)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.3.1.37-48

Abstract

http://dx.doi.org/10.17014/ijog.vol3no1.20084This paper discusses the study on the basalt volcanic rocks and the volcano morphology indicating the existence of an ancient submarine volcano in Tawangsari-Jomboran sub-regency, Sukoharjo- Wonogiri, Central Java. In general, this basalt volcanic rocks were identified as andesite breccia which might be grouped into the Mandalika Formation of Oligosen-Miosen age (Surono et al., 1992). The origin of the Mandalika Formation in relation to the classic sedimentation process and the submarine volcanism is still needed to be evaluated. The present study was based on the detailed descriptions of the rocks both in the field and in the laboratory. The autoclastic basalt outcrops consisting of breccias show the characteristics of the igneous rock fragment component embedded in the groundmass with the same composition, namely igneous rock, dark grey to black in colour; porphyritic texture, rough surface, brecciated; pillow structures, massive, fine vesicularities, amygdaloidal filled with calcite, and radial fractures; calk-alkaline andesite composition ( SiO = 54.71% , K O = 1.15% ). This rock body attains the  dimension of 2 - 5 m length, and 40 cm - 1 m in diameter with the direction of the deposition varies following the direction of the eruption source. Brecciated structures on the surface was controlled by the high cooling rate and the low flow, while the interior of the rock is massive because it was not in a direct contact to the cooler mass outside. Autoclastic basalt breccias and or the pillow basalt lava was interpreted to be formed by the undulating low gradient of morphology with the average angle of <10o. On the other hand, the low basaltic magma viscosity produced the effusive eruption related to the formation of the low angle morphology. The distance between the hills generally composed of pillow basalt is between 500 m - 1 km. The typical pillow structure of the igneous rock as described above is interpreted to be the product of the lava flow related to the effusive eruption  from a submarine volcano located under or close to the seawater surface.   
Karakterisasi sumber gempa Yogyakarta 2006 berdasarkan data GPS Sulaeman, Cecep; Dewi, Lestari Cendekia; Triyoso, Wahyu
Indonesian Journal on Geoscience Vol 3, No 1 (2008)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.3.1.49-56

Abstract

http://dx.doi.org/10.17014/ijog.vol3no1.20085The southern part of Central Jawa is one of earthquake hazard prone areas in Indonesia an earthquake occurred on May 27, 2006 and had the moment magnitude 6.3. Base on the GPS observation, the characterization of the epicenter and source of this Yogyakarta earthquake can be estimated using the displacement estimation and strain at the measurement point by using a simple kriging and sequential gaussian simulation method. The direction of the displacement and maximum shear strain anomaly in this research was shown by the fault of SW – NE direction and the displacement pattern shows that this fault is left lateral strike slip movement. The positive anomaly of the maximum shear strainis located about 10 km east of Bantul, which suggests as the position of Yogyakarta 2006 earthquake source, with the moment seismic and moment magnitude values are 8.1385 x 1025 dyne cm, and 6.5 respectively.    
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 | DOI: 10.17014/ijog.3.2.57-73

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.  
Vulkanisme kompleks Gunung Patiayam di Kecamatan Jekulo, Kabupaten Kudus, Provinsi Jawa Tengah Mulyaningsih, Sri; Bronto, Sutikno; Kusnaedi, Ari; Simon, I.; Prasetyanto, I. W.
Indonesian Journal on Geoscience Vol 3, No 2 (2008)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.3.2.75-88

Abstract

http://dx.doi.org/10.17014/ijog.vol3no2.20082The Mount Patiayam Complex was interpreted by previous researchers as “Patiayam Dome”. That was reasoned by dips following its slope directions. Field data record that lithology of the complex of Mount Patiayam is dominated by volcanic rocks. The summit of the complex is composed of igneous rocks of pyroxene basalt rich in leucite minerals, associated with autoclastic breccia and beds of volcanic breccia rich in pyroxene basalt and pumice, pumiceous breccia, and tuff. Its flanks are composed of epiclastic rocks of lahar and fluvial deposits. Some river valleys, such as Pontang River, locally consist of pyroclastic breccia, autoclastic breccia and pumiceous breccia, that are overlain by marly limestone and black clay of swampy deposits. Based on the rock composition, the volcanism had more dominated geological processes compared with sedimentary. Mineral composition of volcanic deposits of the Mount Patiayam is closer to Mount Lasem volcanic rocks than Mount Muria, i.e. absarockites, shoshonites and trachyandesite. But, based on the long distance between Patiayam and Lasem, about 60 km, those volcanic rocks could not be produced by Mount Lasem. The Patiayam volcanic deposits were produced by its own volcanic activities. Therefore, the complex of Mount Patiayam is a paleo-volcano. The interpretation is also supported by the landsat imagery, showing depression-shapes in a caldera ring-like. There are four caldera features called as Rim 1,Rim 2,Rim 3, and Rim 4, which crosses each others.  
Aplikasi statistika dalam menentukan nilai karakteristik tanah: sebuah studi pustaka Setiawan, Budhi
Indonesian Journal on Geoscience Vol 3, No 2 (2008)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.3.2.89-93

Abstract

http://dx.doi.org/10.17014/ijog.vol3no2.20083In this paper, determination of characteristic value of soil properties based on a statistical method is explained. The value in the limit state design is not the point value as measured by a laboratory or field test. Two confusing concepts in statistical soil mechanics are: the modeling of variability by a random field model and the distinction between the population mean and sample mean. Intrinsically, these two concepts are related to each others. The paper demonstrates that the most confusing thing what is being dilemmas in determining soil characteristic value may be removed by considering a statistical method.  
Kaitan antara karakteristik pantai Provinsi Sumatera Barat dengan potensi kerawanan tsunami Yudhicara, Yudhicara
Indonesian Journal on Geoscience Vol 3, No 2 (2008)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.3.2.95-106

Abstract

http://dx.doi.org/10.17014/ijog.vol3no2.20084The coast of West Sumatera Province has two types of beaches: low lying sandy beach and steep rocky beach. Straight shoreline beaches at Padang beach until Air Bangis at the north and between Pasir Ganting and Salido beach at the south will have a potential tsunami height lower than bay shape beaches like at Kasai Bay, Kabung Bay, Batung Bay and Nibung Bay. A tsunami inundation will be further at a low lying area (low lying sandy beaches) compared with a coastal area which has steep slope and high relief (steep rocky beaches). Gosong beach at Pariaman which has a steep angle of beach slope will have lower tsunami height compared with a low angle beach slope like at Sungai Beramas, Kasai, Kabung, Batung and Nibung bays which have a beach slope about 3° to 5°. The maximum tsunami inundation is assumed to be located at Pasaman and Pasir Pariaman Sub-regencies, while the maximum tsunami height is assumed to be located at the middle of mapped area which has a bay shape. Tsunami is assumed to be arrived early at the southern most of mapped area or close to Muko-muko (Bengkulu). The maximum height difference from sea level was found at Tabai - Pariaman about 5.394 m, while the minimum height difference was found at Carocok Anau about 1.821 m. The horizontal distance measured from the nearest building from the shoreline is about 119 to 173 m. The worst case of tsunami modeling assumed that the maximum tsunami height will be about 32 m and used for reference to make tsunami prone zonation, such as high, moderate and low prone area.    

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