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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
Location
Unknown,
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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
Eo-Oligocene Oil Shales of the Talawi, Lubuktaruk, and Kiliranjao Areas, West Sumatra: Are they potential source rocks? Iqbal, M.; Suwarna, Nana; Syafri, Ildrem; Winantris, Winantris
Indonesian Journal on Geoscience Vol 1, No 3 (2014)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.1.3.135-149

Abstract

DOI:10.17014/ijog.v1i3.198To anticipate the increasing energy demand, additional data and information covering unconventional fossil fuels such as oil shale must be acquired to promote the usage of alternative energy sources to crude oil. The Talawi and Lubuktaruk regions situated within intra-montane Ombilin Basin, and the Kiliranjao assumed to be a small intra montane basin are occupied by Eo-Oligocene sediments of Sangkarewang and Kiliran Formations, respectively. Field activity, geochemical screening techniques, and organic petrographic analysis, supported by SEM mode, are methods used. Most of the oil shale sequence is typically of an organically rich-succession comprising predominantly well-bedded, laminated and fissile, brownish to dark grey organic-rich shale and mudstone rocks. The exinite macerals within oil shale comprise mainly Pediastrum-lamalginite with minor cutinite, resinite, liptodetrinite, sporinite, bituminite, and rare Botryococcus-telalginite. Therefore; the oil shale deposits can be described as “lamosites”. Minor vitrinite maceral is also recognized. TOC analysis on selected shale samples corresponds to a fair up to excellent category of source rock characterization. The hydrogen index (HI) for all samples shows a range of values from 207 - 864, and pyrolysis yield (PY) ranges from 2.67 to 79.72 mg HC/g rock. The kerogen is suggested to be of mixed Type II and Type I autochthonous materials such as alginite, with minor allochthonous substances. Oil samples collected appear to be positioned within more oil prone rather than gas prone. Thermal maturity of the oil shales gained from Tmax value and production index (PI) tends to show immature to marginally/early mature stage. A consistency in the thermal maturity level results by using both Tmax and vitrinite reflectance value is recognized. On the basis of  SEM analysis, the oil shale has undergone a late eodiagenetic process. Thereby, overall, vitrinite reflectance agreeing with Tmax rates, are also consistent with the PI (production index) values and SEM result. By evaluating all the results of geochemical and organic petrological analyses conducted on shale lithologies (shale and mudstone), it can be concluded that the oil shales in those areas have a favourable potential for generation of shale oil or gas to be included as alternative energy resources in the future.
Fault-Plane Markings as Displacement Sense Indicators Djin, Tjia Hong
Indonesian Journal on Geoscience Vol 1, No 3 (2014)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.1.3.151-163

Abstract

DOI:10.17014/ijog.v1i3.177In order to determine the sense of fault motion, older textbooks advise to stroke the fault surface parallel to its striations, or slickensides. The smoother touch is felt when one’s palm moved in the direction of the adjacent fault surface. Laboratory triaxial tests and abundant field evidence proved this ‘smoothness criterion’ of producing ambiguous results. The first published field evidence contradicting the criterion probably originated from the Lokulo area in Central Jawa over half a century ago. Similar findings from elsewhere around the world have also been printed. A practical nomenclature has since developed. The types of reliable fault-plane markings in various rock types are now known. Recognition of fault-movement sense is  essential when outcrop size is limited such as in underground exploration and in trenches.  In addition, the present article also shows examples  how the sense of faulting is applied to arrive at determining structural evolution of a rock body. The method is readily applied to solve structural problems of more extensive geological terranes.
Characteristics of the Triassic Source Rocks of the Aitutu Formation in the (West) Timor Basin Permana, Asep Kurnia; Kusworo, Aries; Prastian, Andi Heri
Indonesian Journal on Geoscience Vol 1, No 3 (2014)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.1.3.165-174

Abstract

DOI:10.17014/ijog.v1i3.192The Triassic rocks of the (West) Timor Basin have been identified that was mainly deposited in the  marine environment. The fine grained clastics and carbonate  rocks of this Triassic marine  facies are considered to be the most promising source rocks potential in this basin. In this paper we present geochemical and petrographic data from outcrop samples of the Triassic carbonate Aitutu Formation, due to emphasized the organic maturation, kerogen type of the organic matter and the origin of the organic matter.  A representative of selected sample were subjected to the Rock-Eval Pyrolisis, vitrinite reflectance and thermal alteration index, bitumen extraction, were analyzed on the GC-MS. The samples were collected from marine deposit of the Triassic Sequence. The TOC values of the analyzed sample range between rich and rich organic richness (0.51% - 9.16%, wt.%, TOC), which consists mainly of type II and III kerogen and the organic matter consider to be predominantly oil/gas prone and gas prone potential. The thermal maturity assessed from Tmax, TAI, and vitrinite reflectance shows an immature to early peak mature stage of the organic matter. The GC-MS analyses of the biomarkers indicate mainly the organic matter derived from mixed source rocks facies containing alga debris and higher plant terrestrial origin.
Carbonate Facies and Sedimentation of the Klapanunggal Formation in Cibinong, West Java Praptisih, Praptisih; Kamtono, Kamtono
Indonesian Journal on Geoscience Vol 1, No 3 (2014)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.1.3.175-183

Abstract

DOI:10.17014/ijog.v1i3.196The limestone of Klapanunggal Formation is well exposed in the area of Cibinong and its surrounding,West Java. Detailed Observation of carbonate rock has been conducted in this area and aims to studythe carbonate facies and its growth environment. The method used in the field is the detailedinvestigation, while mikropaleontology and petrogaphic analysis conducted in the laboratory. Theresult of this study indicate that the carbonate rocks in the study area consists of four facies. namely:(1) boundstone facies, (2) packstone facies, (3) rudstone facies, and (4) limestone breccia facies. Basedon these data be interpreted that the boundstone facies was deposited in the reef front to reef crestenvironment, packstone facies developed on the lower slope, upper slope, and back-reef lagoonenvironment. Rudstone facies formed on the reef front, and breccia limestone facies were formed inthe lower slope. Geographically, the position of the carbonate body environment that is at the reeffront, upper slope and lower slope is expected to be in the North – North East while the reef crest andback reef lagoon is on the South – Southwest.
Developing a Geoinformatic-engineering Stability Modeling Method, using Field Data and GIS Environment: A Case Study from Al Qarara Area in Wadi Musa, Jordan Al Farajat, Mohammmad; Diabat, Abdullah; Al Hassanat, Hussein; Ibweni, Mohammad; Shawaqfeh, Jamal
Indonesian Journal on Geoscience Vol 2, No 1 (2015)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.2.1.1-21

Abstract

DOI:10.17014/ijog.2.1.1-21By applying detailed geological field surveys, the spatial factors affecting geo-engineering stability were used to develop a geo-engineering stability modeling method to identify areas under potential threat of landsliding. The factors affecting geo-engineering stability in Al Qarara area in Petra-Jordan were studied and given assumed rates of importance, where optimization process was run by lag iterations; the produced spatial layers of the different factors were gathered and modeled using GIS; a final stability map was produced using an optimized equation. The produced map was validated qualitatively and quantitatively, where a comparison was made between the reality in the field and several maps of different equation. The modeling method which was developed in the context of this study proved to be suitable to produce micro-zonation maps of areas having landslide risk. Further applications on the method in other areas suffering landslides will further improve it.
Contrasting Two Facies of Muncung Granite in Lingga Regency Using Major, Trace, and Rare Earth Element Geochemistry Irzon, Ronaldo
Indonesian Journal on Geoscience Vol 2, No 1 (2015)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.2.1.23-33

Abstract

DOI:10.17014/ijog.2.1.23-33Lingga Regency is located in the main range of the famous Southeast Asia granitic belt related to tin resources. There are two granitic units in this region: the S-type Muncung Granite and I-type Tanjungbuku Granite. XRF and ICP-MS were used to measure the major, trace, and rare earth elements of nine Muncung Granite samples. Two different patterns were identified from major data plotting on Harker variation diagram. Granitic rocks from Lingga and Selayar Islands are classified as A facies while others from Singkep Island is B facies. This paper used graphs and variation diagrams to reveal the differences of those two facies. Thus, REE correlation to SiO2, trace element spider diagram, and REE spider diagram show more contrasts correlation. However, both facies are syn-collisional and High-K calc-alkaline granites. Some identical characters with other granitic units in Peninsular Malaysia were also detected in this work.
Radon and Thoron Exhalation Rates from Surface Soil of Bangka - Belitung Islands, Indonesia Syarbaini, Syarbaini; Pudjadi, E.
Indonesian Journal on Geoscience Vol 2, No 1 (2015)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.2.1.35-42

Abstract

DOI:10.17014/ijog.2.1.35-42Radon and thoron exhalation rate from soil is one of the most important factors that can influence the radioactivity level in the environment. Radon and thoron gases are produced by the decay of the radioactive elements those are radium and thorium in the soil, where its concentration depends on the soil conditions and the local geological background. In this paper, the results of radon and thoron exhalation rate measurements from surface soil of Bangka Belitung Islands at thirty six measurement sites are presented. Exhalation rates of radon and thoron were measured by using an accumulation chamber equipped with a solid-state alpha particle detector. Furthermore, the correlations between radon and thoron exhalation rates with their parent nuclide (226Ra and 232Th) concentrations in collected soil samples from the same locations were also evaluated. The result of the measurement shows that mostly the distribution of radon and thoron is similar to 226Ra and 232Th, eventhough it was not a good correlation between radon and thoron exhalation rate with their parent activity concentrations (226Ra and 232Th) due to the environmental factors that can influence the radon and thoron mobilities in the soil. In comparison to a world average, Bangka Belitung Islands have the 222Rn and 220Rn exhalation rates higher than the world average value for the regions with normal background radiation.
The Influence of ENSO/IOD on SST Signal in Kendari, Southeast Sulawesi Waters: 27-year-records of Sr/Ca from Porites corals Cahyarini, Sri Yudawati; Suharsono, Suharsono
Indonesian Journal on Geoscience Vol 2, No 1 (2015)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.2.1.43-51

Abstract

DOI:10.17014/ijog.2.1.43-51Indonesia is an interesting and important location for a climate study, because it is located in the centre of a warm pool and adjacent to Pacific and Indian Oceans. Long records of climate data are required from this region to more understand the climate variability and the response of global warming. Geochemical proxies derived from Porites corals are believed to be an excellent climate recorder. Sr/Ca content in Porites corals from Kendari, Southeast Sulawesi shows that seasonal variability of SST is resolved by coral Sr/Ca from this region. The monsoon strongly influences reconstructed SST from coral Sr/Ca. Coral SST shows strong power spectrum at the 2.75 year period. Annual to interannual coral SST signal is stronger than the decadal to interdecadal signal. Both ENSO and IOD influence coral SST at two-month and three-month lags respectively.
DMT Method Approach for Liquefaction Hazard Vulnerability Mapping in Bantul Regency, Yogyakarta Province, Indonesia Sugianti, Khori; Sari, Anggun Mayang; Syahbana, Arifan Jaya
Indonesian Journal on Geoscience Vol 2, No 1 (2015)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.2.1.53-61

Abstract

DOI:10.17014/ijog.2.1.53-61On May 27 2006, an earthquake (Mw 6.2) occurring in Bantul, Yogyakarta Special Province, triggered liquefaction phenomenon such as sand boiling and lateral spreading. Knowledge of the liquefied soil layers is required to mitigate the hazard. The purpose of this research is to determine the depth and thickness of liquefiable soil layers using the flat blade dilatometer test (DMT) method. The horizontal stress index values (KD) obtained from the DMT were used to calculate the cyclic resistance ratio (CRR), while the PGA (peak ground acceleration) calculated by the software EZ-FRISK 7.52 were employed to determine the cyclic stress ratio (CSR). The DMT-based liquefaction potential analysis shows that the thickness of liquefiable soil layers ranges from 1.8 to 4.0 m. These results show a good agreement with the previous analysis based on CPT (cone penetration test) data. The analysis also indicated that, for the given earthquake magnitude and PGA, the liquefiable soil layers are characterized by a range of maximum KD value from 2.1 to 3.7.
Developing a Land Suitability Index for Agricultural uses in Dry Lands from Geologic Point of View Using GIS - a Case Study from Jordan Al Farajat, Mohammmad; Mohammad, Alsharifa Hind; Diabat, Abdullah; Al Ibraheem, Hassan
Indonesian Journal on Geoscience Vol 2, No 2 (2015)
Publisher : Geological Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.17014/ijog.2.2.63-76

Abstract

DOI:10.17014/ijog.2.2.63-76In the context of the study, a Multi-criteria evaluation (MCE) in GIS was used in developing suitability index to optimize suitable lands for agricultural uses and seasonal farming in dry lands from geologic point of view. This study was performed in the areas between Mafraq and Zarqa Cities in Jordan which are classified as arid lands. The study aims at protecting groundwater from pollution, reducing soil salting, reducing irrigation water loss caused by evaporation, and increasing crop productivity. The geo-environmental parameters of the named area including geology, groundwater depths, soil depths and textures, climatic conditions, topographic settings, and groundwater vulnerability conditions were mapped and converted into layers with special rates, given weights, and then modeled using the multi criteria evaluation (MCE) option, using Decision Making Modeling in IDRISI (GIS software) to reach at the best choice of lands for agricultural activities, and also to determine which of these lands are suitable for summer farming and which are suitable for winter farming.