cover
Contact Name
bernadeta subandini astuti
Contact Email
bernadeta.palguno@gmail.com
Phone
+6222-7213793
Journal Mail Official
ijog@bgl.esdm.go.id
Editorial Address
Jl. Diponegoro No. 57 Bandung, Indonesia
Location
Kab. sleman,
Daerah istimewa yogyakarta
INDONESIA
Indonesian Journal on Geoscience
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 324 Documents
Evolution of Rajabasa Volcano in Kalianda Area and Its Vicinity, South Lampung Regency Bronto, Sutikno; Asmoro, P.; Hartono, G.; Sulistiyono, Sulistiyono
Indonesian Journal on Geoscience Vol 7, No 1 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2816.767 KB) | DOI: 10.17014/ijog.7.1.11-25

Abstract

DOI: 10.17014/ijog.v7i1.132Rajabasa Volcano (± 1281 m) and Lampung Tuff, located in the South Lampung Regency, is the main point in order to understand the evolution of Quaternary volcanism in the area. A remote sensing analysis and field geologic work are the methods of the study. The volcanism began with the construction period of the Pre-Rajabasa composite cone which was followed by the destruction period of the cone to form the Pre-Rajabasa Caldera having ca. 25 km in diameter. The present Rajabasa Volcano, along with cones of flank eruptions and monogenesis, has appeared in the Pre-Rajabasa Caldera depression. Those volcanic activities are considered as the second construction period. During the first and the second construction periods, basaltic to andesitic lava flows, pyroclastic breccias, and tuffs were erupted. The Rajabasa eruption points moved in WNW - ESE direction, which were possibly controlled by a subsurface weak zone. The Pre-Rajabasa Caldera erupted voluminous Lampung Tuffs having rhyolite in composition, and they are considered as a combination of pyroclastic falls, flows, and surges, or pyroclastic density currents.
Engineering Geological Investigation of Slow Moving Landslide in Jahiyang Village, Salawu, Tasikmalaya Regency Sarah, Dwi; Daryono, M. R.
Indonesian Journal on Geoscience Vol 7, No 1 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1786.031 KB) | DOI: 10.17014/ijog.7.1.27-38

Abstract

DOI: 10.17014/ijog.v7i1.133An understanding of landslide mechanism is imperative to determine the appropriate mitigation method. The slow moving landslide (creeping) which occurred in Kampung Salawangi, Jahiyang Village, Salawu Subregency, Tasikmalaya had caused economical and environmental losses due to the frequent active movement particularly following rainfall events. Engineering geological investigation and slope stability analysis were carried out in the studied area in order to elucidate the mechanism of the landslide. The engineering geological investigation consists of local topographical mapping, geotechnical drillings, hand borings, cone penetration, and laboratory tests. The slope stability assessment of the recent landslide was conducted by a finite element method. The results of engineering geological data analysis show that the studied area is composed of residual soils of soft to firm sandy silt and loose to compact silty sand and base rock of fresh to weathered volcanic breccias with groundwater level varying between 3 - 16 m. The engineering properties of the residual soils indicate that the sandy silt is of high plasticity and the shear strength properties of the sandy silt and silty sand show low value with effective cohesion of 6.0 - 21.74 kPa and effective friction angle of 12.00 - 25.980. The assessment of slope stability shows that the stability of the studied area is largely influenced by the rise of groundwater level marked by the decrease of safety factor and increase of slope displacement.
Morphostructure Control Towards the Development of Mahawu Volcanic Complex, North Sulawesi Poedjoprajitno, S.
Indonesian Journal on Geoscience Vol 7, No 1 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3302.311 KB) | DOI: 10.17014/ijog.7.1.39-54

Abstract

DOI: 10.17014/ijog.v7i1.134The studied area, situated in northeastern part of North Sulawesi Arm, is dominantly occupied by the Mahawu, Linau, Tompusu, and Kasurutan volcanic rocks. Using remote sensing data, such as landsat image, black and white panchromatic aerial photograph, and IFSAR image, morphology-origin unit and morphology lineament can be interpreted. Four morphology-origin units, those are Mahawu Volcano Complex, Intra-montane Plain structure, Linau Volcano Complex, and Lacustrine Plain are recognized. Furthermore, morphological lineament pattern was statistically processed to find out the general stress direction in the area to determine the probability of the structural morphology occurrence in the Mahawu Volcano Complex. The result shows that generally the development pattern of volcanic cones are irregular, except the Mahawu Volcano Complex showing a linear pattern. This lineament pattern is interpreted as a NW - SE fault pattern controlling the rise of magma. At least, two tectonic and two eruption periods occurred regularly at different time from the Quaternary age till the present.
Tsunami Characteristics along The Coast of Biak Island based on the 1996 Biak Tsunami Traces Yudhicara, Yudhicara
Indonesian Journal on Geoscience Vol 7, No 1 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1045.437 KB) | DOI: 10.17014/ijog.7.1.55-66

Abstract

DOI: 10.17014/ijog.v7i1.135Identification on tsunami traces had been conducted along the coast of Biak Island, Papua, to recognize the character of tsunami potential in this region, referring to the 1996 tsunami event. This study is to observe the influence of tsunami to the environment and tsunami character itself which can be learned from tsunami deposit. According to the 1996 Biak tsunami run up distributions, it can be observed that the maximum tsunami run up was found at the coast which has an undulating to steep morphology rather than other places which has a relatively flat one. The 1996 Biak Tsunami arrival times were approximately between 10 and 15 minutes, such as at the northern and southern coasts of Biak, except for the western one which is about 1 to 5 minutes. This was influenced by the local bathymetry and another possible source triggering tsunami such as a local submarine landslide. The number of tsunami waves were between 2 and 4, and the second one was usually the highest. Based on a sedimentological analysis, the 1996 tsunami deposit is characterized by the dominant coarse sand, while grain size distribution curve shows a character of transportation process similar to an ordinary beach process dominated by saltation current. The foraminifera fossil content tends to indicate that the tsunami deposit was derived from > 200 m seafloor depth (bathyal zone).
The Paleo-Orientations of Northwestern Borneo and Adjacent South China Sea Basins Tjia, H. D.
Indonesian Journal on Geoscience Vol 7, No 2 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (801.735 KB) | DOI: 10.17014/ijog.7.2.67-76

Abstract

DOI: 10.17014/ijog.v7i2.136Limited paleomagnetic data from West Kalimantan and southwestern Sarawak appear to indicate counter-clockwise (CCW) rotation of over 50 degrees during Cenozoic. On the other hand, similar studies from Sabah show conflicting results in terms of paleo-positions. This CCW information and other plate tectonic considerations have formed the base of Southeast Asia’s plate reconstructions that have seen print in a number of updated versions. The existing publications on extensive field and exploration data, including geological stress fields from wellbore breakouts, on northwestern Borneo and basins of South China Sea have not been taken into account. The latter wealth of information already established that the region under discussion consists of a mosaic-like assemblage of diverse tectono-stratigraphic terranes, each with separate tectonic development. Stress fields changed in different ways in the different terranes indicating definitively that regional, progressive CCW rotation of Borneo is not possible.
Thermal and Infrared Studies of Garnierite from the Soroako Nickeliferous Laterite Deposit, Sulawesi, Indonesia Sufriadin, Sufriadin; Idrus, Arifudin; Pramumijoyo, S.; Warmada, I. W.; Nur, I.; Imai, A.; Imran, A. M.; Kaharuddin, Kaharuddin
Indonesian Journal on Geoscience Vol 7, No 2 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3347.354 KB) | DOI: 10.17014/ijog.7.2.77-85

Abstract

DOI: 10.17014/ijog.v7i2.137Mineralogical characterization of some garnierite samples from Soroako have been conducted using X-ray diffraction, thermal analysis, and infrared spectroscopy methods. XRD patterns reveal the samples mainly containing the mixture of kerolite (talc-like phase) and serpentine with minor smectite, sepiolite, and silica. Thermal analyses of garnierite samples indicated by DTA curves are in good agreement with patterns that have been reported in literature. Three endothermic peaks normally occur in the ranges between 58º C and <800º C illustrating three steps of weight losses: adsorbed, bound, and hydroxyl/crystal water. One additional weight loss in low temperature region of sepiolite is corresponding to the lost of zeolitic water. Infrared spectra appeared in 3800 - 3200 cm-1 region generally exhibit broad absorption bands, indicating low crystallinities of studied samples and can be assigned to the presence of hydroxyl group bonded to octahedral coordination mainly Mg atom. The bands observed at 1660 cm-1, 1639 cm-1, 1637 cm-1, and 1633 cm-1 in all samples indicate water molecules. FTIR spectra displaying the strong bands at 1045 cm-1, 1038 cm-1, and 1036 cm-1 could be related to the presence of Si-O-Si bonds linking to tetrahedral coordination. The strong absorption bands appeared at 511 cm-1, 505 cm-1, 499 cm-1, and 496 cm-1 in respective samples are attributed to divalent cation bonds (e.g. Mg, Ni-O). Both TG/DTA and FTIR seem to be the powerful tool in diagnosing the crystal chemistry of garnierite which is mainly composed of phyllosilicate minerals.
Limestone Diagenetic Records Based on Petrographic Data of Sentolo Formation at Hargorejo Traverse, Kokap, Kulonprogo Maryanto, Sigit
Indonesian Journal on Geoscience Vol 7, No 2 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1325.009 KB) | DOI: 10.17014/ijog.7.2.87-99

Abstract

DOI: 10.17014/ijog.v7i2.138Limestone diagenetic records of Sentolo Formation have been studied in order to trace the history of the geological processes after the deposition of the rocks. A stratigraphic measure traverse was made in Hargorejo Village, Kulonprogo District, to identify the petrological characteristics of the Sentolo Formation. Limestone samples were taken along this traverse, and were used for a petrographic analysis. The analysis of thirtyeight limestone samples shows that the type is dominated by bioclastic grainstones which have been affected by various kinds of diagenetic processes after the deposition. The diagenetic processes recorded under the polarization microscope include cementation, replacement, bioturbation, micritization, recrystallization, dolomitization, compaction, fracturing, and leaching.
Depositional Environment of the Batuasih Formation on the Basis of Foraminifera Content: A Case Study in Sukabumi Region, West Java Province, Indonesia Hendrizan, M.; Praptisih, Praptisih; Putra, Purna S.
Indonesian Journal on Geoscience Vol 7, No 2 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3546.177 KB) | DOI: 10.17014/ijog.7.2.101 - 112

Abstract

DOI: 10.17014/ijog.v7i2.139The research was carried out on the sediments of the Batuasih Formation cropping out at Batuasih Village, Cibatu River, Padaarang Sukabumi. Data obtained from field observation, as well as foraminifera and sedimentology analyses conducted in the laboratory, were used to interpret its depositional environment. The investigation was focused on planktonic and benthic foraminiferal assemblages for depositional environment interpretation that might not be used by previous researchers. The Batuasih Formation is composed of black shaly claystone, where the lower part is rich in clay ball, and limestone intercalations in the upper part of the formation. In Cibatu Section, no clay balls is recognized in the lower part, but intercalations of limestone still occur. However, a contrast difference is found in Padaarang section, where green claystone interbeds with fine-grained sandstone. The Batuasih Formation conformably overlies the Walat Formation containing conglomerate. Foraminifera fossil found in the Batuasih Formation consists of bad preserved black benthic and planktonic foraminifera, more abundant towards the lower part of formation. Based on foraminifera assemblage comprising genus Uvigerina, Cibicides, Elphidium, Operculina, Bulimina, Bolivina, Eponides, and Neoconorbina, supported by sedimentology data, the Batuasih Formation was deposited in a shallow to deep marine environtment, during Early Oligocene (P19) time. Upwards to be the Rajamandala Formation, the depositional environment tends to be shallower gradually.
Allostratigraphy of Punung Paleoreef based on Lithofacies Distributions, Jlubang Area, Pacitan Region-East Java Premonowati, Premonowati; Prastistho, B.; Firdaus, I. M.
Indonesian Journal on Geoscience Vol 7, No 2 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1619.43 KB) | DOI: 10.17014/ijog.7.2.113 - 122

Abstract

DOI: 10.17014/ijog.v7i2.140Lithologically, Punung Formation as a paleoreef comprises coral boundstone rhodolith, algal grainstone, algal packstone, algal wackestone, algal floatstone, and algal rudstone. It is dominated by red algae and had formed a fringing reef in a warmly shallow marine environment. They built seven phases of paleoreef complex. Each paleoreef complex has been bounded by a local unconformity that is characterized by caliche. The Jaten Formation has becomes the base of the Punung paleoreef which build up by an angular unconformity contact on uppermost part. It consists of tuffaceous wacky sandstone with silicate cement. The formation as the reef base indicates two factors. The external factor because of the decrease of a volcanic activity and the internal one was caused by the depositional environment of the Jaten Formation becoming shallower. The subsurface runoff systems in many caves (like: Jaran cave and others) have the same southward direction to the dipping direction of algal grainstone lithofacies of Punung Formation. The vertical caves are formed by a jointing system.
Remote Sensing Analysis of Recent Carbonate Platforms, East of Sabah: Potential Analogues for Miocene Carbonate Platforms of the South China Sea Chalabi, Aicha; Pierson, B.; Talib, Jasmi Ab
Indonesian Journal on Geoscience Vol 7, No 3 (2012)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2725.673 KB) | DOI: 10.17014/ijog.7.3.123-135

Abstract

DOI: 10.17014/ijog.v7i3.141Recent carbonate platforms may provide useful analogues for fossil platforms and reefs, and could allow the generation of quantitative tools for the prediction of facies distribution, reservoir volumes, and reservoir quality. Data from these modern analogues would greatly enhance our ability to construct more reliable and calibrated reservoir models for carbonate fossil fields, such as the Miocene carbonate platforms of Central Luconia Province, Sarawak. In this study, carbonate facies maps and quantitative reservoir data will be generated by using remote sensing techniques. Satellite imageries over the carbonate platforms east of Sabah have been acquired and processed for generating facies maps. In order to produce a reliable facies map, the composition and grain size distribution of the sediments that make up individual facies must be known in order to determine the classes that have been identified on the initial facies maps. Samples collected from the Gaya and Selekan platforms were analyzed and the results of grain size analysis are illustrated.