cover
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
-
Editorial Address
-
Location
Unknown,
Unknown
INDONESIA
BULLETIN OF THE MARINE GEOLOGY
ISSN : 14106175     EISSN : 25278843     DOI : -
Core Subject : Science,
Bulletin of the Marine Geology is a scientific journal of Marine geoscience that is published periodically, twice a year (June and December). The publication identification could be recognized on the ISSN 1410-6175 (print) and e-ISSN: 2527-8843 (on-line) twice a year (June & December) and it has been accredited by Lembaga Ilmu Pengetahuan Indonesia (Indonesian Institute of Sciences) by Decree Number: 818/E/2015. As an open access journal, thus all content are freely available without any charge to the user. Users are allowed to download, and distribute the full texts of the articles without permission from the publisher.
Arjuna Subject : -
Articles 5 Documents
Search results for , issue "Vol 39, No 2 (2024)" : 5 Documents clear
GRAVITY MODELING OF SUBSURFACE STRUCTURES AND RESERVOIR CHARACTERIZATION USING SEISMIC INVERSION IN THE NIAS BASIN Wibowo, Ramadhana; Setiadi, Imam; Firdaus, Yulinar; Rahardiawan, Riza
BULLETIN OF THE MARINE GEOLOGY Vol 39, No 2 (2024)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.39.2.2024.890

Abstract

The development of interpretation techniques opens new exploration opportunities in the forearc basins of western Indonesia, such as the Nias Basin which show signs of oil and gas seepage. Gravity and seismic inversion analysis were used to look into the Nias Basin in order to evaluate its subsurface structure, the location of sedimentary sub-basins, and the possible presence of hydrocarbon reservoirs. After filtering the data for the Complete Bouguer Anomaly (CBA), a residual anomaly was obtained. This allowed for the quantitative interpretation of structures below the surface using 2D gravity forward modelling. Seismic and well data interpretation includes sensitivity analysis, a well-seismic tie, picking horizons, and acoustic impedance (AI) inversion. The residual gravity anomaly reveals eight sub-basin patterns spread out in the Nias Basin with a relative continuity direction of northwest-southeast following the lineaments of basement highs. The subsurface geological model identified four rock formations. From deepest to shallowest, these units are metamorphic bedrock (2.7 g/cc), Lelematua Formation (2.5 g/cc), Gomo Formation (2.4 g/cc), and Gunungsitoli Formation with an overlying alluvium (2.25 g/cc). Interpretation of well and seismic suggests a target zone at a 2,017 – 2,101 meters depth. Using a model-based hard constraint for AI inversion in this zone indicates possible carbonate reservoirs. Based on sensitivity analysis with an interval of 34,000 - 47,000 (ft/s)*(g/cc), an AI cutoff value of more than 34,000 (ft/s)*(g/cc) was obtained. The carbonate is estimated to be a tight carbonate in the limestone of the Gomo Formation.
ZOOPLANKTON DISTRIBUTION FROM BACKSCATTER DATA OF ADCP INSTRUMENT IN WEST SUMATRA WATERS Napitupulu, Gandhi; Farihah, Rizqi Ayu; Manik, Henry Munandar; Larasati, Oktavira Dwi Demia; Napitupulu, Moses; Bernawis, Lamona Irmudyawati; Radjawane, Ivonne Milichristi; Kusmanto, Edi
BULLETIN OF THE MARINE GEOLOGY Vol 39, No 2 (2024)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.39.2.2024.871

Abstract

Acoustic Doppler Current Profiler (ADCP) conventionally used to monitor ocean current profiles and potentially detect zooplankton distribution remains largely unexplored. Zooplankton are key consumers in the marine food chain, therefore understanding their distribution is critical. This study aims to map the distribution of zooplankton in West Sumatra waters using ADCP backscatter data. Data analyzed encompass ocean current measurements, backscatter, and conductivity-temperature-depth (CTD) profiles collected from March 1 to 3, 2017. Raw ADCP digital counts were converted into mean volume backscattering strength (MVBS) in dB using sonar equations, proportional to zooplankton biomass. The conversion process involved corrections for sound attenuation due to distance and water absorption, ADCP transducer angle correction, and noise correction. Processing results revealed zooplankton distribution in raw ADCP data ranging from 20 to 160 counts and in MVBS data spanning -140 dB to -40 dB. MVBS values derived from ADCP acoustic signal processing were filtered within the -100 dB to -60 dB range, representing the zooplankton backscatter range. Zooplankton distribution was observed at depths of 0-300 m. Vertical zooplankton distribution was generally high in the 100-200 m layer and decreased at 0-100 m and 200-300 m. This is attributed to the influence of the Equatorial Undercurrent transporting zooplankton biomass from the Indian Ocean to West Sumatra waters at depths of 100-200 m, characterized by high salinity (34.6-35.2 PSU) and cold temperatures (19°-21°C). This study demonstrates the utility of ADCP in observing zooplankton distribution based on their backscatter values and the influence of ocean currents in transporting zooplankton biomass.
ENVIRONMENTAL CHANGES DURING THE LATE MIOCENE TO PLEISTOCENE USING SMALL FORAMINIFERA AND PALYNOMORPHS IN THE KUTAI BASIN, EAST KALIMANTAN Nisa, Firda Aulya; Jurnaliah, Lia; Winantris, Winantris; Nugrahanto, Kuntadi
BULLETIN OF THE MARINE GEOLOGY Vol 39, No 2 (2024)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.39.2.2024.855

Abstract

The Kutai Basin is one of the large basins in East Kalimantan which was formed during the Tertiary Period. The sedimentation process in this basin is strongly influenced by sea level changes. This study conducts quantitative analysis using the abundance of small foraminifera and palynomorphs in well “FN O-1” located in the northern part of offshore Kutai Basin. It applies the Planktonic-Benthic Ratio to determine the range of the bathymetric-related environments in the entire depth interval. The aims of this study are to interpret the sequence stratigraphy in the Kutai Basin using small foraminifera and palynomorphs associated with sea level changes. Three sequence stratigraphy phases are identified; TST (Transgressive System Tract), HST (Highstand System Tract), and FSST (Falling Stage System Tract), from the Late Miocene to Pleistocene in an inner to outer neritic environment. The results of the P/B ratio calculation show that wells with a depth of 1,230 feet to 12,180 feet are predominantly located in the inner neritic zone with a ratio percentage less than 20%. The highest abundance of small benthic foraminifera reaching  534 individuals was found at a depth of 1,650 feet within the TST phase. The most abundant planktonic foraminifera (452 individuals) was observed at a depth of 1,350 feet during the TST-HST transition. The FSST revealed the most abundance of mangrove palynomorphs with 100 fossil grains at 11,640 feet and 56 back-mangrove palynomorphs fossils were identified within the TST at 2,340 feet. This study concludes that the abundance of small foraminifera and palynomorphs suggests both marine and terrestrial influences on the basin.
VARIABILITY OF SEA SURFACE TEMPERATURE AND SALINITY IN MAKASSAR STRAIT DURING THE LAST GLACIAL MAXIMUM Larasati, Oktavira Dwi Demia; Hendrizan, Marfasran; Rachmayani, Rima; Napitupulu, Gandhi
BULLETIN OF THE MARINE GEOLOGY Vol 39, No 2 (2024)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.39.2.2024.882

Abstract

Indonesian Throughflow (ITF), which is part of the global thermohaline circulation, is known to play an important role in the heat exchange between the Pacific and Indian Oceans. The flow of the ITF is highly complex, it depends on temperature and salinity. This study presents a proxy study from 25,000–18,000 years ago from two sites that are connected by the Indonesian Throughflow in the Makassar Strait. Oceanographic characteristics, including Sea Surface Temperature (SST) and Sea Surface Salinity (SSS) were reconstructed and analyzed during the Last Glacial Maximum (LGM) period. A 295 cm marine sediment core coded SO217-18522 (1°24.106'N; 119°04.781'E, water depth 978 m) and SO217-18519 (0°34.329'N; 118°06.859'E, water depth 1658 m) from the SONNE 217 research cruise in 2011 was used as research material. Oxygen isotope  analysis, planktonic foraminiferal Mg/Ca geochemistry, and radiocarbon dating were used in this study. The SST reconstruction shows that the temperature during the LGM reach the minimum during ~20 ka BP and the SST value was significantly lower by ~2–3 °C compared to the Late Holocene value. The SST also shows significant cooler in marine sediment SO2017-8519 located in the southern site compared to the northern site. Salinity reconstructions during the LGM shows that SSS value was 0.82–1.13 psu higher than in the Holocene. The south–north gradients of SST and SSS in the Makassar Strait were larger over the 23.2–24.2 ka BP (SST gradient by 0.5–1 °C and SSS gradien by 1–1.7 psu) compared to the Late Holocene. The increase in SST and SSS gradients during the ~20 ka BP likely indicates a weakened intensity of the surface ITF relative to conditions during the Late Holocene.
MIOCENE PALEOGEOGRAPHIC RECONSTRUCTION IN THE SANGATTA AREA, EAST KALIMANTAN BASED ON CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY AND BENTHONIC FORAMINIFERAL ANALYSIS Jambak, Moehammad Ali; Deny, Deny; Rendy, Rendy; Syavitri, Dewi
BULLETIN OF THE MARINE GEOLOGY Vol 39, No 2 (2024)
Publisher : Marine Geological Institute of Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32693/bomg.39.2.2024.869

Abstract

The Kutai Basin is a significant hydrocarbon potential basin with up to 15 km thickness of Tertiary sediments. It is dominated by a complex deltaic system to a marine shelf environment. Thus, it is crucial to understand the facies distribution in the area. This study was carried out to assess, correlate, and reconstruct the paleoceanographic evolution of the basin using lithological and microfossil data obtained from five exploration wells. The lithostratigraphic analysis was used to identify lithological units of each well, while the calcareous nannofossils biostratigraphy was applied to estimate the age and benthic foraminifera was analysed for paleoenvironmental interpretation. The findings reveal that the study region consisted of claystone, siltstone, shale, coal, and sandstone of the Gelingseh and Kelandasan Formation. The age of these lithological units is assigned from the Middle to Late Miocene epoch (NN6-NN11), based on the presence of some nannofossil index fossils such as Catinaster coalitus, Discoaster hamatus, Discoaster quinqueramus, Discoaster calcaris, and Coronocyclus nitescens. Benthic foraminifera assemblages are primarily composed of arenaceous species such as Trochamina spp. and Haplophragmoides spp., indicating a transitional environment, though some species such as Elphidium spp. and several planktonic foraminifera species appeared, which reflect marine influence on the research area. Based on the biofacies analysis; mudflats, tidal flats, delta front, prodelta-marine shelf, and fluvial plain were formed during the Middle to Late Miocene in the studied area.

Page 1 of 1 | Total Record : 5