ORCID Profile
0000-0002-9549-2778
Current Organisations
University of Queensland
,
University of Oxford
,
Universitas Indonesia
,
Universitas Padjadjaran
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012053
Abstract: Muarajambi Temple Compound situated in the side of a river in Jambi Province, Indonesia. Due to its vicinity to the river, the compound has experienced various geological event associated to the river sedimentation, such as river flood and alluvial sedimentation. We have collected two soil s le from beneath an excavated human-made structure in the sideway of a river. The first s le was collected right in bottom of the structure, while the second s le was collected around 20cm beneath the structure. Taking s le right beneath the structure is ideal for the analyses because this would avoid contamination after the temple construction. The pollen and spore content from these s les were analysed to understand its variation. From the analyses, we found that the first younger s le has larger AP (arboreal pollen) percentage but smaller NAP (non-arboreal pollen) compared to the second s le. This indicate that the vegetation is less dense in the first s le. This study might indicate the environmental changes due to human activities, particularly human activities around the temple compound which led to the construction of the temple compound itself.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012042
Abstract: Sand as part of sedimentary material can be consisted of single mineral fragments, rock fragments, or even biogenic materials. Nusa Tenggara is an archipelago that was formed due to the meeting of the Indian Ocean Plate and the Eurasian Plate which supported by other geological processes. The stratigraphy of these islands is dominated by carbonate rocks, volcanic rocks, coastal deposits and alluvium. Due to the variation of the rock composition, there is a large possibility that mineralogy sediment material found in the coastal area will be different from one place to other. This study aims to analyse variations on coastal deposits in a number of specific locations in the Nusa Tenggara Islands. This study was carried out by mineralogical and petrographic analysis of sand s les from six coastal areas in Nusa Tenggara Islands. The mineral composition of coastal sand was identified using hand loupe to give general understanding. After that, the petrographic analyses were implemented to give detailed mineralogical analyses of each sand. Mineralogical studies are specialized in study of the physical structure and chemical composition of each mineral, while petrographic studies can support the details of every physical information obtained through macroscopic observations. Data are retrieved by taking sand s les directly in the research field in a certain amount. This s le is separated then for macroscopic analysis while the other parts are made in a thin section. The thin section will be used for petrographic analysis under a polarization microscope. The analysis result shows that there are variations in coastal sediment components and it most likely does to different rock found around such area.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012051
Abstract: Remote sensing has become one of the most used methods in geothermal exploration. This technology is used to detect the presence of lineaments located in the area of geothermal exploration. The lineament can be expressed in the form of ridges and valleys. These features are closely related to the existence of geological structures. Geological structures act as weak zones (permeable zones) for the fluid to come out to the surface which will provide the circulation that forms the geothermal system. The research area is geographically located in 06°35’58” S and 106°17’01” E. Overall, the area of the research is about 325 km 2 included 51 sub-districts in Lebak Regency, Province of Banten. This research area covers the entire area of Mount Endut and east of Mount Talaga and was included in the geological map of Leuwidamar dominated by Pleistocene Endut volcanic rocks (Qpv) which consists of volcanic breccia, lava, and tuff. The geological structures that developed in the study area are in the form of faults and folds. The data used in lineaments extraction were Digital Elevation Model derived from ASTER GDEM which has a vertical accuracy of 10–25 m. Meanwhile, the data on the existence of manifestations were obtained from the Geothermal Potential book published by the Geological Agency, Ministry of Energy and Mineral Resources. In extracting lineaments, the PCI Geomatica software was automatically used with the LINE algorithm. In the calculation of ground surface temperature, ENVI software is used together with The Law of Wien Shift. The general direction of alignments obtained is NNW-SSE. There are 5 unexpected faults related to the distribution of surface manifestations. The results of the structure interpretation in general show the relationship with the existence of surface ground temperature anomalies distribution. This is caused by the existence of a weak zone (permeable zone) as a place for the hot fluid to escape which will affect the surface temperature of the ground.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012050
Abstract: Landslide is one of the most common disaster in Bogor City and Bogor Regency. BNPB stated that between 2013–2018 there are 44 landslides with death toll of 68 persons. Therefore, it is important to generate map to identify landslide susceptibility in research area. In this study, we try to create landslide susceptibility map of Bogor area (Bogor Regency and Bogor City) using Analytical Hierarchy Process (AHP). We use various factors to identify landslide susceptibility, including slope curvature, slope gradient, topographic wetness index, slope aspect, elevation, stream power index, distance to river, river density, distance to lineament, lineament density, lithology type, soil type, normalized differential vegetation index, rain intensity, land cover, distance to road, and building density. Various factors above are derivative from openly accessed data of Digital Elevation Model (DEM), landslide distribution, Bakosurtanal Map, Landsat 8 Imagery, engineering geology map, rain intensity data, and soil type map. After all, input data collected, the landslide susceptibility map is created using the AHP method. To validate the result, Receiver Operating Characteristic (ROC) applied, the value of the area under the curve (AUC) to determine the success rate of the AHP method is 0.834, this value represents that the landslide suscepbility map produced by the AHP method is a good model.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012072
Abstract: Hydrothermal alteration is a great indicator of thermal fluid dynamics, especially in a geothermal system. Hydrothermally altered minerals are formed based on temperature and the properties of the protolith. Hydrothermal alteration s les from Gunung Endut Geothermal Working Area were analysed using petrography methods. Importance in determining the hydrothermal alteration for geothermal alteration are use as geothermometers, predict scaling and corrosion, estimate fluid pH and many more. Temperature, permeability and fluid type involved in the alteration process were identified based on the thin section observation. Majority of the s les shows the presence of clay minerals, chlorite and pyrite, indicating a moderate intensity of alteration formed under an argillic alteration environment at ≤ 180 °C. Based on the altered minerals observed under the petrographic microscopy, we then deduce that acidic fluids are the main type of fluid found in Gunung Endut Geothermal Working Area because that argillic alteration minerals showed acid environment.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012057
Abstract: Banten region is known to have subvolcanic hydrocarbon system but no proven play despite oil seeps and the potential source rock have been identified in this area. A Geochemical analysis of source rock have been done on Gunung Endut, Banten Province. There are four coaly shale s le from Genteng Formation and Bojongmanik Formation collected and analysed in this study. The purpose of this study is to understand the influence of volcanic environment towards the quality, quantity and maturity of source rock based on TOC, pyrolysis, and vitrinite reflectance analyses. The result obtained showed TOC value between 8–18 wt% which indicated excellent petroleum potential from the source rock. In addition, Pyrolysis data showed S1 value between 0.05–0.19, S2 value between 1.52–11.53, S3 value between 4.10–7.57 and Tmax 414.8–523.2 °C. From both analyses, TOC and Pyrolysis, the source rock is categorized as Type 3 Kerogen producing gas and Type 4. Based on its maturity, three s le are categorized as immature while one specimen is categorized as postmature. Furthermore, Vitrinite Reflectance analysis result shows Ro value between 0.27–0.63 that support the result of pyrolysis analysis. Maturity anomaly found in the s le is presumed to be caused by intrusion that have been identified by the geological mapping in the same region. The condition on the surface may also reflect the source rock in the subsurface. A number of source rock in Banten region may be matured due to intrusion that related to volcanic activities. Subsurface zone with abundance igneous bodies will have different maturity compare to other area. Hence, it is important for petroleum exploration activities in Banten region or other volcanic area to properly identify the distribution of subsurface igneous body due to its effect to the source rock maturity.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012024
Abstract: Pottery is a ceramic which generally used as household utensils or religious necessities such as spiritual ceremonies. This object has been used by society since long time ago that make it has certain historical and cultural values. One problem with pottery that it is hard to define its source. We believe that mineralogy could help finding the source of the pottery by comparing mineralogy of pottery and mineralogy of alluvial sand that usually used for pottery. This study was carried out to analyze the pottery-forming material of pottery fragments in the Muaro Jambi Temple complex and compare them with the Batanghari River sediments on the opposite to the temple. Data retrieval is done by collecting pottery fragments in the excavation field and taking sand s les in the downstream of the Batanghari River. The fragments of pottery and river sands were separated based on their texture and analyzed using microscope. Each material will be described based on its physical appearance and frequency of existence. From the study we found that minerals found in the pottery fragments from Muaro Jambi have similarity with the mineralogy of alluvial sand from Batanghari River. Thus, it might be a good indication that there is a correlation between them. From this research, we also conclude that the mineralogy characteristic could be useful for identifying the source of pottery.
Publisher: IOP Publishing
Date: 08-2019
DOI: 10.1088/1755-1315/279/1/012045
Abstract: Geochemical assessment was completed in Gunung Endut geothermal area to determine fluid characteristics discharging from their natural surface manifestations. Gunung Endut geothermal area is centralised in the western part of the region. Three surface manifestations located in Desa Handeuleum, Cikawah and Gajrug appears along the apparent structural (fault) line. Diluted chloride- carbonate water belongs to partially equilibrated group may indicate mixing between chloride water and groundwater. Quartz and Na-K geothermometer indicated reservoir temperature of 107 – 127 ºC and 111 – 132 ºC respectively. Geoindicators of Cl/B indicated that there are two separate reservoirs in the sub-surface. Geoindicators of Na/K and Na/Ca revealed that all the manifestations lie in the outflow zone of Gunung Endut geothermal area.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012028
Abstract: Warukin Formation is one of the coal bearing formation in Kalimantan that has significant coal resource. The formation as Middle Miocene Age and deposited in generally regression stage. In addition to coal, it is composed of mudstone and sandstone with siderite nodule, with some coal seams also have parting of carbonaceous mudstone. Coal from Warukin has various quality that possibly related to the changes in depositional environment. This study attempted to understand the relation between depositional environment and the coal quality. To do that, coal is s led from coal seams that can be found in study area. After collected, the s le then analyzed using lithofacies, electrofacies, biostratigraphy, and maceral analysis. These various analyses would uncover the slight variation on depositional setting between each seam in study area. Later, the result then correlated with the coal quality analyses that have been done before. From the study, it is concluded that some coal s le has higher Sulphur content that related with deposition with more seawater influence. Biostratigraphy analyses indicate that the interburden deposited in shallow marine setting, thus indicate that the depositional interchanged between transitional setting to shallow marine. Electrofacies also indicate that there were progradation and retrogradation process in the depositional activities. Maceral studies also indicate different type of maceral component that reflect the depositional variation within the seam.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012017
Abstract: Hydrothermal alteration is an interaction between rock and hydrothermal fluid by means changing the mineralogical composition of the rock. This process is controlled by permeability, chemical composition, temperature, pressure, and duration of the hydrothermal alteration. Gunung Pancar, located in West Java, is considered an outflow for Gunung Gede Geothermal System. Typical geothermal surface manifestations found around Gunung Pancar are hot springs, warm ground and surface alteration. Basic geological mapping was conducted followed by water and altered rock s ling. Petrographic and diffraction methods are completed to confirm altered protolith. Water analyses were conducted to determine water type and origin. Alteration zonation is then inferred based on the water type, intensity of alteration and then cross referenced with indication of structural geological features. Zonation reveals that the intensity of alteration gets weaker as it moves away from the apparent faults. The result suggested that the permeability of the host rock affects thermal fluid movement around Gunung Pancar and subsequently the local geothermal conceptual model.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012016
Abstract: Bangka Island is an important tin producer in Indonesia, mostly from the secondary tin deposits. However, the secondary tin deposit is depleting, causing further exploration shifted to the primary tin mineral. The purpose of this study is to make a mineralization model of primary tin deposit in Bangka Island. Methods that implemented in this study are petrographic analysis, mineragraphic analysis, XRD (X-Ray Diffraction), and XRF (X-Ray Fluorescence) analysis. The studied rock s les that consisted of granite, meta-sandstone, and sandstone. Some of the rocks are altered rocks with varying intensity. Petrographic and mineragraphic analysis show the presence of minerals that indicate the primary tin deposits, such as cassiterite, tourmaline, topaz, sericite, pyrite, and sphalerite. XRF analysis shows data about the value of Sn elements so that they can be classified into two classes, very high grade ( 800 ppm), and low grade (100–200 ppm). XRD analysis is necessary to do to determine the type and intensity of alterations that occur in the study area. The results of each analysis will provide supporting information regarding the primary tin mineralization process in Bangka Island.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012038
Abstract: Process of deFormation has an effect on both dynamic and regional metamorphic rocks. Metamorphic rock of Manunggal Formation can be found as large outcrops in Karangsambung, Central Java. In this research, we did geological mapping in the Manunggal Formation outcrop area and took rock s les. The rock s les are then analysis macroscopically to determine their metamorphic facies. From our study, we are able to identify the various degrees of metamorphism within the study area. This variation are concluded from the detailed macroscopic of mineral composition and rock texture of the rock s les from Manunggal Formation. The metamorphism process in rocks produced foliation textures on metamorphic rocks that are either foliated like phyllite and schist, or non-foliated such as green rock, serpentinite, and hornfels. All of this variation are plotted into the geological map and showing specific trend that might be related to past tectonic activity in the study area.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012026
Abstract: Mount Endut is a volcano located in the eastern part of Banten Province. Previous studies revealed that Mount Endut consists mainly of Quaternary volcanic and Tertiary plutonic igneous rocks respectively. This research focuses on the petrology of igneous rocks found in the southern region of Mount Endut in order to determine the type of igneous rocks, evolution of magma, and reconfirming historical geological process occurring in Mount Endut area. Petrographic analysis was performed on 11 s les and geochemical analysis was performed on 30 s les. Petrographic analysis revealed three types of igneous rocks, andesite porphyry, diorite porphyry, and dacite porphyry. Furthermore, geochemical analysis revealed that the igneous rocks in Mount Endut are comprised of basaltic andesite, andesite, dacite, basaltic trachy-andesite, trachy-andesite, and trachyte or trachydacite which originated from calc-alkaline magma series. The integration of petrographic and geochemical analysis supports the regional geological process where Mount Endut was formed either in an island arc or an active continental margin. The first section in your paper.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012047
Abstract: Sebuku Island is located in Kotabaru Regency, South Kalimantan and is known as one of the main sources of laterite iron in Indonesia. Based on its tectonic setting, Sebuku Island is located within the suture zone that connects Southwest Borneo Block (SWB) and East Java West Sulawesi Block (EJWB). Due to its tectonic setting, Sebuku Island is composed of various rocks associated with suture zone, such as ophiolite rocks. The ophiolite rocks could host mineralization that occurred in Sebuku Island. The aim of this study is to determine the characteristics of lithology and mineralization as determinants of geological processes that influence the formation of rocks and mineral deposits in Sebuku Island. This study was carried out through petrological, petrographic, ore microscopy analysis, and geochemical analysis (x-ray fluorescence). 22 rock s les from Sebuku Island were collected and the result of this research shows that the chromite host rocks are composed of serpentinized dunite and serpentinite. Chromite minerals (FeCr 2 O 4 ) were found in massive forms with cataclastic, brecciated texture and disseminated with pull-apart texture. Based on observation of the polished sections, it is known that the associated mineral of chromite is magnetite which is an alteration of chromite minerals. Chromitite chemical data shows the chromite composition is Al-rich (Cr# = 0.6) and classified as podiform chromitite formed by fractional crystallization. There are two magma series of igneous rock in the study area i.e. tholeiitic series consists of ultramafic-mafic rocks and calc-alkaline consists of micro-diorite. The abundance of Al 2 O 3 and TiO 2 in chromitite shows that Al-rich chromitite has formed in Supra Subduction Zone (SSZ) and has occurred near or above the Moho-transition zone.
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012029
Abstract: Ciseeng geothermal field is located Northwest of West Java 40 km from Jakarta. Three surface manifestations are in Tirta Sayaga, Panjang Mountain, and Peyek Mountain. This study aims to build a hydrogeochemical model based on water analysis. The secondary regional geological data are retrieved to complete geological information of Ciseeng. The research method is ided into several stages: introduction includes the literature study, data collection includes the measurement of temperature and pH in several surface manifestations, rock s ling and structural geology analysis in Ciseeng. The type of manifestation that can be found in Ciseeng is a warm pool with chloride fluid type. Extensive travertine deposits were found in all three locations. The fluid temperature of three surface manifestations is about 30-38 °C with pH 6. According to the measurement of Na-K-Ca geothermometer, the reservoir temperature in Ciseeng geothermal field is 180 °C. The three manifestations of Ciseeng geothermal field are classified as mature water based on a ternary plot diagram. The isotopic analysis shows shifting in O 18 indicating hydrothermal process due to magmatic activities in the subsurface. It is predicted that Ciseeng geothermal field is part of Salak/Pangrango Mountain geothermal system. The presence of surface manifestation confirms that geological structure trending from North to South, play a significant role to circulate the heated fluid in the subsurface and subsequently to the surface. The result is a geothermal conceptual model of Ciseeng field that shows the fluid origin and movement in the subsurface.
Publisher: Author(s)
Date: 2018
DOI: 10.1063/1.5064176
Publisher: Author(s)
Date: 2018
DOI: 10.1063/1.5064188
Publisher: Author(s)
Date: 2018
DOI: 10.1063/1.5064177
Publisher: Informa UK Limited
Date: 21-08-2017
Publisher: IOP Publishing
Date: 07-2020
DOI: 10.1088/1755-1315/538/1/012070
Abstract: Gunung Endut, located in Banten Province, has geothermal pr ospect area in its mountain slope. Some of the area of Gunung Endut has limestone facies which commonly deposited in marine environment. Based on the regional geological map of Leuwidamar, limestone facies are the member of Bojongmanik Formation within the Bogor Physiographic Zone. In Gunung Endut, limestone was developed during the pre-volcanic period, meanwhile most of limestone in Java are found as outcrop in Southern Mountains Zone formed during the post-volcanic period. This study focused on macroscopic and microscopic identification of limestone in order to determine the distribution of facies and the history of limestone sedimentation in the area of Gunung Endut. The macroscopic and microscopic feature of the rock s les are analyzed and classified using modified Dunham classification by Embry-Klovan. The result of the analyses will provide information about the limestone facies distribution and geological history with better detail in the study area than previously known.
Publisher: IOP Publishing
Date: 2021
DOI: 10.1088/1742-6596/1725/1/012076
Abstract: Travertine deposits are carbonate rocks consists mainly of calcium carbonate minerals, supersaturated from bicarbonate-rich water. Both recent and fossil travertine deposits are found in Ciseeng geothermal field, West Java. The travertine deposits are distributed around three distinctive areas Tirta Sayaga, Mount Panjang and Mount Peyek. This study aims to determine minerals found in travertine deposits in Ciseeng geothermal field. Mineralogical analysis can determine the evolution of hydrology system and local climate change. Principal methods of analysis consists of petrographic and diffraction methods. Analysis results indicate similar mineral composition of calcite and microcrystalline carbonate (micrite) between recent and fossil travertine deposit with more erse texture in fossil travertine due to the evolution of water composition affecting deposition and diagenesis process. The absence of aragonite indicates a low-temperature geothermal system.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Felix Sihombing.