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All Journal Bulletin of Scientific Contribution : Geology IJOG : Indonesian Journal on Geoscience Jurnal Geominerba Journal of Geosciences and Applied Geology

Ahmad Helman Hamdani, Ahmad Helman

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Author-ID : 568345

Civil Engineering, Building, Construction & Architecture Earth & Planetary Sciences Education Energy Engineering Environmental Science Other

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Articles

Biomarker Composition of Some Oil Seeps from West Sulawesi, Indonesia Sutadiwiria, Yarra; Hamdani, Ahmad Helman; Sendjaja, Yoga Andriana; Haryanto, Iyan; Yeftamikha, Yeftamikha
Indonesian Journal on Geoscience Vol 5, No 3 (2018)
Publisher : Geological Agency

DOI: 10.17014/ijog.5.3.211-220A suite of oil seep samples collected from the Lariang and Karama Basins, West Sulawesi, Indonesia, have been analyzed using GC and GCMS techniques. Their biomarker compositions have been used to reveal the likely source rock that produces oil. These oil seep samples contain a range in both the concentration of hydrocarbons present and certain level of biodegradation experienced. All sterane m/z 217 data display a familiar pattern of steranes with carbon numbers from 27 to 29 together with pregnane and homo-pregnanes, including rearranged steranes. Triterpane (m/z 191) data show a moderate content of tricyclic terpanes (Tri/C30H), medium to high ratio of norhopane/hopane (C29/C30), and medium to high abundant land plan marker such as resin bicadinanes(Bic/C30H) and oleananes (Ol/C30H). The presence of high abundant oleananes in these samples has been interpreted as the evidence for a marine influence during early diagenesis that may occur by marine or via re-deposition of peat organics in marine sediments. Hence, these results state that the organic matter facies for their source rock oil seep samples from the West Sulawesi region are detected as mixed between allochthonous macerals from typical terrestrial higher plants transported into the basin from distal swamps and soils and some marine organic matter.

Tectonic Control on the Formation of Cleats in the Coal Beds of the Sajau Formation, Berau Basin, Northeast Kalimantan Sudradjat, Adjat; Hamdani, Ahmad Helman
Indonesian Journal on Geoscience Vol 5, No 3 (2018)
Publisher : Geological Agency

DOI: 10.17014/ijog.5.3.235-250Coal seams of lignite- to subbituminous rank of Pliocene-age from the Sajau Formation of the Berau Basin are characterized by the presence of a natural fracture system, including cleats. Often, these opening-mode fractures consist of two orthogonal sets (face and butt cleats), both almost perpendicular to the bedding. This paper describes the distribution of orientation, spacing, and aperture of cleats formed in the seams of the Sajau Formation. All observations and measurements were conducted at macroscopic, mesoscopic, and microscopic scales. The butt cleat mean orientations are NE-SW and NW-SE, whereas the face cleat mean orientations are NNE-SSW and NE-SE, and the cleat dip is at a high angle of 75° to the north. The angles between the orientations of these cleat sets are nearly 90°; that is, they are orthogonal. The spacing of the macroface cleats is between 9.52 and 14.46 cm (averaging 11.61 cm), while the spacing of the butt cleats is between 2.3 and 11.3 cm (averaging 5.35 cm). The mean aperture is 0.54 mm. In contrast, the mean spacing of the mesoface cleats is 3.09 mm, and the aperture measurements of these cleats range from 0.0478 to 0.0741 mm (averaging 0.0549 mm). The results obtained from outcrops and X-ray CT (computed tomography) scan clearly indicate that the NNE-SSW face cleat orientations are strictly parallel to the elongation of the main tectonic structures in the studied area. Their origin may be explained by their relationship with local tectonic stress (the maximum principal stress, σ1, was horizontal). Partial least square analysis of data collected from cleats and faults in the area indicates that a power law distribution exists between the cleat characteristics (spacing, density, and aperture), and the distance of the faults (R2 = 0.56). Cleat formation in the Sajau Formation was mainly controlled by the mechanical response to tectonic stresses, which generated a unique cleat network in the coal. Based on the SEM photography, it is concluded that the development of microcleats in the Sajau Formation resulted from both endogenic processes and tectonic activities as indicated by the change in the shape of the cleats, from straight line to curved shape and branching (intersection of multiple cleats that form a conical network at the end).

NILAI KUALITAS MASSA BATUAN DENGAN METODE ROCK MASS RATING PADA AREA LOWWALL PIT X, PT. BUKIT ASAM TBK. SUMATERA SELATAN Dandy, Leonardus; Khoirullah, Nur; Hamdani, Ahmad Helman
JURNAL GEOMINERBA (JURNAL GEOLOGI, MINERAL DAN BATUBARA) Vol 8 No 2 (2023): Jurnal Geominerba - 2023
Publisher : PPSDM Geominerba

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.58522/ppsdm22.v8i2.139

This research is located in the Muara Enim Formation which is included in the South Sumatera Basin and this formation is a coal-bearing formation in the study area. Rock Mass Rating classification is a rock mass classification method which can be used as an initial reference for engineering geology because it describes the rock mass characteristics which assosiated with slope stability. Mining at PT Bukit Asam, Tbk. using the open pit mining method so the control process is related to slope stability. The research was conducted on lowwall slope area which was designed to follow the slope of the rock layers that have the potential for plane slides so it is important to know the characteristics of the rock mass as an initial reference for the stability of a slope. The quality of the rock mass rating is determined by the rating of each parameter which is carried out by using the scanline method as a field calculation. Based on the rating of rock mass rating, the study area is divided into three rock mass classes, rock mass class II (good rock), rock mass class III (fair rock), and rock mass class IV (poor rock).

The Face Mask Waste Recycling Generated During Covid-19 Pandemic In Indonesia Hamdani, Ahmad Helman; Haryanto, Agus Didit
Journal of Geological Sciences and Applied Geology Vol 5, No 2 (2021): Journal of Geological Science and Applied Geology
Publisher : Faculty of Geological Engineering, Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24198/gsag.v5i2.34996

In Indonesia, the COVID-19 disease has developed rapidly as found on April 20, 2021, there were 1,614,849 positive cases of Covid-19. The increase in cases of the coronavirus has resulted in an increase in the amount of medical waste during the Covid-19. The most common medical waste is face masks, both from hospitals and households. This increase in medical waste will cause environmental damage or health problems. "A viable solution for reducing the impact of face mask waste on health and the environment is to recycle the face mask mechanically, chemically, and thermally. The proximate, ultimate, FTIR analysis and hardness testing have been carried out to obtain the potential for recycled products. The test results show that carbon ( C ) and volatile matter (VM)are found in large quantities; polypropylene content is a detected type of plastic. Thus, recycled products can generate potential as a source of renewable energy, cement replacement materials, pipes, packaging materials.. Besides being able to produce new products, this process can also eliminate viruses.

RELATIONSHIP BETWEEN MOLECULE STRUCTURE AND COAL MATURITY OF BAYAH FORMATION BASED ON X-RAY DIFFRACTION ANALYSIS Ardiansyah, Muhammad Iqbal; Hamdani, Ahmad Helman; Haryanto, Agus Didit
Journal of Geological Sciences and Applied Geology Vol 5, No 3 (2021): Journal of Geological Science and Applied Geology
Publisher : Faculty of Geological Engineering, Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24198/gsag.v5i3.38349

Coal is the richest source of energy used worldwide. Characterization of the structure of coal is one of the important things in studying the use of coal. X-Ray Diffraction (XRD) has been successfully used as a tool to study the molecular structure characteristics of coal with various coal ranks. There are five coal samples to be examined from the Bayah Formation in Lebak Regency, Banten. This study aims to measure the crystal structure parameters in coal and use them to predict coal maturity level. The results of XRD analysis showed that the five coal samples had the same crystal structure characteristics. The value of d002 is in the range of 3.87 to 3.96 Å, indicating that the studied sample has a low content of microcrystalline units. The measurement of carbon aromaticity (fa) values in the study area ranged from 0.67 to 0.76. There is a strong correlation between the value of coal maturity as measured by vitrinite reflectance (Ro) and the value of aromaticity; which is characterized by a correlation value of r of 0.88. Thus, the aromaticity (fa) value of XRD can be used to predict the maturity level of coal.

Evaluation of Acid-Base Accounting to Predict the Acid Water of Overburden in Coal Mines in Horna Areas, West Papua Province, Indonesia Hamdani, Ahmad Helman; Hutabarat, Johanes; Haryanto, Iyan; Ilmi, Nisa Nurul
Journal of Geological Sciences and Applied Geology Vol 2, No 3 (2017): Journal of Geological Sciences and Applied Geology
Publisher : Faculty of Geological Engineering, Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24198/gsag.v2i3.15618

Acid-Base Accounting (ABA) is an analytical procedure to measure the balance between the acid neutralization and acid generation properties of any geologic material. ABA is considered tools to predict post-mining water. Overburden samples were collected from the coalfields of Horna coalmines. Maximum potential acidity (MPA), acid neutralizing capacity (ANC), acid net neutralization potential (ANG), Net Acid Producing Potential (NAPP), net acid generation (NAG), and ANC/MPA ratios were determined for each site based on ABA. Most of the sample from R1, R4, R-13, and R14 showing the pH of net acid generation of overburden ranges from 3.2 – 4.47 and positively acid net neutralization potential (be classified as the PAF-LC (Low Capacity Potential Acid NAPP) varies from 2.07 – 21.27 2.4 kg/t H2SO4 indicate that the samples are classified as the PAF-LC (Low Capacity Potential Acid Former (LC-PAF) to the PAF-MC (Moderately Capacity Potential Acid Former (MC-PAF). Other samples from R13 (four samples) has negatively NAPP and pHNAG between 6,21 – 7,10, therefore should be classified as the NAF; two samples from R13 indicated the uncertainty (UC) due to high pHNGA (6,82-7,15).

Origin of Oil Seeps in West Sulawesi Onshore, Indonesia: Geochemical Constraints and Paleogeographic Reconstruction of the Source Facies Sutadiwiria, Yarra; Yeftamikha, .; Hamdani, Ahmad Helman; Andriana, Yoga; Haryanto, Iyan; Sunardi, Edy
Journal of Geological Sciences and Applied Geology Vol 2, No 1 (2017): Journal of Geological Sciences and Applied Geology
Publisher : Faculty of Geological Engineering, Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24198/gsag.v2i1.13420

ABSTRACTNumerous oil and gas seeps occur at onshore West and South Sulawesi. These may indicate the presence of active petroleum system in subsurface hence the area is worthy for further exploration. No discovery well so far in this area. Therefore, the seeps provide significant data to build integrated petroleum system analysis.A number of geochemical analysis were conducted on the oil seeps and rock samples from outcrop and well cuttings to reveal the source rocks that generate the oils. Triterpane m/z 191 shows low content of tricyclic terpane, low norhopane to hopane, and abundant oleanane. Sterane m/z 217 and bicyclic alkane m/z 123 show dominant C29 sterane and bicadinane. These biomarkers indicate that the source of oils are coals and/or coaly shales deposited in fluvio-deltaic setting. Contribution from marine input is shown in Karama region to the south.Based on stratigraphic setting of West and South Sulawesi, the best candidate for the source of oil seeps is Eocene coals or coaly shales of Toraja or Kalumpang Formation. The Eocene coal samples have been characterized and show similar GC alkane distribution with the oil seeps. Contribution from marine facies, which may age-equivalent to these coals are shown in Karama region.Aromatic methyl phenanthrene m/z 178 and m/z 192 were also analyzed to know their maturities and they were generated at maturity level equivalent with Ro 0.8-1.0 %.Based on geochemical constraints and geologic data, a paleogeographic setting of Eocene Toraja/Kalumpang Formation was built to know better about the paleo-source facies of the oils and its geochemical characteristics. Keywords: Biomarker, coaly shales, Toraja/Kalumpang Formation

THE SUSTAINABLE MANAGEMENT OF POST-MINING LANDUSE; AN AHP APPROACH A CASE STUDY: EX-SAND MINING IN INDRAMAYU REGENCY, WEST JAVA Hamdani, Ahmad Helman; Hutabarat, Johanes; Muhamadsyah, Faisal
Journal of Geological Sciences and Applied Geology Vol 4, No 3 (2021): Journal of Geological Science and Applied Geology
Publisher : Faculty of Geological Engineering, Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24198/gsag.v4i3.32224

Recently, the sustainable management of post-mining land use has received great attention. The mining-closure, due to the mine has no longer economic value, or the mined material has run out; often leaving poor landscapes and degraded land. The mining company have to rehabilitate the ex-mining land so that it can be returned to its original baseline stage or can be used for other more useful activities. The objective of research is to arrange the sustainable management plan of post-mining land use at ex sand-mining in Indramayu Regency, West Java. The Analytical Hierarchy Process (AHP) approach used to determine the priority of activities that will be carried out on the land. Several criteria and alternative were calculated by Saaty’s AHP pairwise comparison scale. The research results reveal that in post mining land use management based on sustainable management, economic criteria must be considered first, followed by environmental, socio-culture and finally technical criteria. Fishery, cattle breeding and agriculture were found to be the optimal alternative for sand post‐mining land use.

STRATIGRAFI BATUAN DAERAH SELAJAMBE DAN SEKITARNYA, KECAMATAN SELAJAMBE, KABUPATEN KUNINGAN PROPINSI JAWA BARAT -, Abbas; Hamdani, Ahmad Helman; Muhamadsyah, Faizal
Bulletin of Scientific Contribution Vol 13, No 1 (2015): Bulletin of Scientific Contribution
Publisher : Fakultas Teknik Geologi Universitas Padjadjaran

Geographically, the research area is located at 108° 27' 7.3548" BT - 108° 32' 7.3572" BT and 07° 0' 9.6336" - 07° 5' 9.6324" LS. Administratively belongs to Selajambe District, Kuningan Regency, West Java. Based on the lithostatigraphy aspect, the research area is divided into four units which are (from the oldest) : Sandstone Unit (Tmbp), Monomic Breccia Unit (Tmbx), Volcanic Breccia Unit (Qbv) and Tuff Unit (Qt).Geological history of the region began at Middle Miocene, research area was deep sea environment, submarine fan depositional system due to turbidite mechanism, to formed sandstone unit (Tmbp). With increasing sediment supply without the accommodation space inadequate to sediment were prograding and made closer the source area, following by sedimentation of rough material to form the monomic breccia unit (Tmbx). At Miocene -Pliocene periods there was an increase of tectonic activity that caused the rocks to folded, jointed and faulted. During the Pleistocene, area of research has become the terrestrial environment and in that time volcanism was occured to formed the volcanic breccia unit (Qbv) and are conformably overlain by tuff unit (Qt) at the top.

Co-Authors Abbas - Adjat Sudradjat Agus Didit Haryanto -, Agus Didit Haryanto Andriana, Yoga Ardiansyah, Muhammad Iqbal Arista Muhartanto, Arista Dandy, Leonardus Edy Sunardi Faizal Muhamadsyah, Faizal Iyan Haryanto, Iyan Johanes Hutabarat Khoirullah, Nur Lili Fauzielly Muhamadsyah, Faisal Nisa Nurul Ilmi Safrizal Safrizal Triwerdhana, Afriadhi Yarra Sutadiwiria Yeftamikha, . Yeftamikha, Yeftamikha Yoga Andriana Sendjaja, Yoga Andriana

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