Bulletin of the Marine Geology最新文献

{"title":"LATE HOLOCENE HEAVY METALS RECORD OF JAKARTA BAY SEDIMENTS","authors":"R. Zuraida, R. Rahardiawan, Y. Permanawati, I. Adhirana, Andrian Ibrahim, Nazar Nurdin, H. Permana","doi":"10.32693/bomg.33.2.2018.569","DOIUrl":"https://doi.org/10.32693/bomg.33.2.2018.569","url":null,"abstract":"This paper reports copper, zinc, lead, cadmium, and chromium records of Jakarta Bay sediment since 600 AD and reonstruct environmental changes since that time. Jakarta Bay This study uses samples from a 150 cm long gravity core (TJ-17, 106.902488°E, 5.99381°S) that was acquired from the eastern part of Jakarta Bay in 2010 onboard RV Geomarin I by the Marine Geological Institute. Heavy metal content in Jakarta Bay sediments is used to track environmental changes onland from this site. Heavy metal concentration was analyzed using atomic absorption spectrometry on bulk samples that were taken in 5 cm interval. The results yield background level of Cu at 16 ppm, Zn at 75 ppm, Pb at 20 ppm, Cd at 0.01 – 0.15 ppm, and at Cr 80 ppm. Vertical record of heavy metals show two stages of environmental changes in the region: from 600 AD to 1600 AD and 1800 AD onward. These changes are interpeted as related to land use changes caused by human activity in the West Java region.","PeriodicalId":31610,"journal":{"name":"Bulletin of the Marine Geology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48540797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Foraminiferal Analysis Related to Paleoceanographic Changes of Arafura Sea and Surrounding During Holocene","authors":"L. Gustiantini, S. A. Piranti, R. Zuraida, S. Hyun, D. Ranawijaya, F. X. H. H. Prabowo","doi":"10.32693/bomg.33.2.2018.571","DOIUrl":"https://doi.org/10.32693/bomg.33.2.2018.571","url":null,"abstract":"Arafura Sea is located between Papua and Australia as a part of Sahul Shelf. It is strongly influenced by ITF, ITCZ replacement, monsoon, and ENSO circulation that interplay with local mechanism. To understand the paleoceanographic parameter changes during Holocene, we conducted foraminiferal quantitative analysis from a 152 cm length sediment core (Aru–07), in every 10 cm interval. This sediment core was retrieved from 134o00’33.6” E, 5o55’51.59” S, by RV Geomarin 3 belongs to Marine Geological Institute. Geochronology of the sediment was reconstructed based on 2 AMS 14C age dates, analyzed on organic samples. We identified 129 species of benthic and 24 species of planktonic foraminifera that is dominated by planktonic specimens with average of 53.14%. Predominant species are Globigerina bulloides (16.16%), Globigerinoides ruber (11.18%), and Neogloboquadrina dutertrei (5.65%). Benthic type is dominated by genera Bolivina, Bulimina, and Uvigerina by 25.86% (average). This might suggest eutrophic condition associated with carbon-rich or low oxygen level (dysoxic) condition. Single linkage cluster analysis revealed 3 paleoenvironmental zones, are: Zone I: older than 3.9 kyr BP, characterized by depleted oxygen level and nutrient enrichment compared to that of younger zone. Zone II: 3.9 – 2 kyr BP, characterized by oxygen content enrichment and deeper thermocline layer, related to the sea level rise during more neutral or La Niña like condition. Zone III: younger than 2 kyr BP, represent shallower thermocline layer, higher productivity which might be related to upwelling, and dysoxic condition. Sea level might be declined that related to more El Niño like condition.Keywords: Paleoceanographic changes, upwelling, foraminiferal analysis, Arafura SeaLaut Arafura berlokasi di antara Papua dan Australia sebagai bagian dari Paparan Sahul. Kondisi iklim sangat dipengaruhi oleh ITF, perpindahan ITCZ, monsun, dan ENSO yang berinteraksi dengan mekanisme lokal. Untuk memahami perubahan parameter oseanografi selama Holosen, kami melakukan analisis kuantitatif mikrofauna foraminifera, yang dilakukan terhadap sebuah bor sedimen laut sepanjang 152 cm (Aru–07) pada interval setiap 10 cm. Bor sedimen bawah laut ini telah diambil pada posisi 134o00’33.6” BT, 5o55’51.59” LS, menggunakan kapal penelitian Geomarin 3, Pusat Penelitian Geologi Kelautan. Geokronologi sedimen berdasarkan 2 radiocarbon dating, dianalisis dari sampel organik pada sedimen. Teridentifikasi 129 spesies bentik dan 24 spesies plangtonik yang didominasi oleh plangtonik dengan persentase rata-rata 53.14%. Foraminifera Jenis–jenis yang dominan antara lain Globigerina bulloides (16.16%), Globigerinoides ruber (11.18%), dan Neogloboquadrina dutertrei (5.65%). Sedangkan jenis bentik didominasi oleh genus Bolivina, Bulimina, dan Uvigerina, dengan persentase rata–rata 25.86%. Hal tersebut kemungkinan menunjukkan kondisi eutropik yang berasosiasi dengan kondisi kaya karbon dan rendah level oksigen (disoxi","PeriodicalId":31610,"journal":{"name":"Bulletin of the Marine Geology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44705351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Channel Controlled Foraminiferal Distribution off Bakkhali, West Bengal, India","authors":"S. Tripathi, S. Resmi, Satyendra Baraik, D. Sengupta, A. Lahiri","doi":"10.32693/bomg.33.2.2018.557","DOIUrl":"https://doi.org/10.32693/bomg.33.2.2018.557","url":null,"abstract":"Study area is situated 8 km south of the Bakkhali Island, West Bengal of India and its subaqueous environment influenced by the fluvial processes such as Hooghly River in west and its distributary like Muri Ganga in the centre and Saptamukhi River in the east. To understand the submarine behavior of these channels and associated meiobenthos, total of 28 sediment samples have been studied in detail. The study reveal that a total of fifteen species of recent benthic foraminifera belonging to 13 genera under 11 families were present and their distribution mainly controlled by channel morphology and sediment character. Based on the distribution of these benthic foraminiferal species, two assemblages have been identified. First assemblage, observed within the Hooghly and Muri Ganga channel, where salinity is comparatively low and sediment is mainly dominated by silt and clay. The most dominating benthic foraminifers of this assemblage are Ammobaculites agglutinans, Cribrostomoides jeffreysii and Asterorotalia trispinosa. Whereas, second assemblage mainly comprise of A. trispinosa, Ammonia beccarii, Asterorotalia spp., Elphidium excavatum, Elphidium crispum and Ammonia tepida noticed over the sand bars and adjoining shallow area. Keywords: channel morphology, Muri Ganga, Hooghly, sand bar","PeriodicalId":31610,"journal":{"name":"Bulletin of the Marine Geology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42050718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectral Decomposition with Continuous Wavelet Transform for Hydrocarbon Zone Detection of North Bali Waters","authors":"T. B. Nainggolan, Muh. Nur Iqlal Manai, Subarsyah Subarsyah","doi":"10.32693/bomg.33.2.2018.556","DOIUrl":"https://doi.org/10.32693/bomg.33.2.2018.556","url":null,"abstract":"The East Java Basin is developed from an oceanic basin in front of Late Cretaceous Java Trench subduction zone to presently back-arc basin behind the Java-Lombok volcanic arc to the south. Many studies conclude hydrocarbon discovery in deep carbonate Ngimbang Formation. However, as a result of the active tectonic history of the region, there are fractures from Ngimbang Formation upward to the Oligo-Miocene Kujung Formation. It developes enhanced permeability medium for a good hydrocarbon migration. This paper presents shallow gas detection zone in the Mundu Formation by applying the spectral decomposition method with continous wavelet transform. Spectral decomposition can be effectively used to identify hydrocarbon reservoirs by analyzing seismic data in the frequency domain. Spectral decomposition with frequency 20 Hz shows the potential zone at time 779 - 832 ms which is suitable with depth 2237.5 - 2355.6 feet in well TRG-1. This method is supported with quantitative calculation of petrophysical analysis that determines 5 pay flag zones range from 2208.5 feet until 2347.5 feet.Keywords : East Java Basin, spectral decomposition, continuous wavelet transform, petrophysical analysisCekungan Jawa Timur terbentuk dari cekungan samudera di tepi zona subduksi pulau Jawa pada masa Cretaseous/Kapur Akhir hingga cekungan busur belakang sistem vulkanik Jawa-Lombok di selatan. Banyak penelitian menyimpulkan penemuan hidrokarbon pada lapisan karbonat Formasi Ngimbang yang dalam. Namun, sebagai akibat dari sejarah tektonik aktif dari wilayah tersebut, terdapat rekahan dari Formasi Ngimbang sampai ke atas hingga Formasi Kujung pada masa Oligo-Miosen. Kejadian tersebut menyebabkan timbulnya peningkatan permeabilitas medium yang baik untuk migrasi hidrokarbon. Makalah ini menyajikan deteksi zona gas dangkal pada Formasi Mundu dengan menerapkan metode dekomposisi spektral dengan transformasi wavelet kontinyu. Dekomposisi spektral dapat secara efektif digunakan untuk mengidentifikasi reservoir hidrokarbon dengan menganalisa data seismik dalam domain frekuensi. Dekomposisi spektral dengan frekuensi 20 Hz menunjukkan zona potensial pada kedalaman domain waktu 779 - 832 ms yang sesuai dengan 2237.5 - 2355.6 kaki pada sumur TRG-1. Metode ini didukung dengan perhitungan kuantitatif analisa petrofisika yang menentukan 5 zona gas mulai dari 2208.5 kaki hingga 2.347.5 kaki.Kata kunci : Cekungan Jawa Timur, dekomposisi spektral, transformasi wavelet kontinyu, analisa petrofisika","PeriodicalId":31610,"journal":{"name":"Bulletin of the Marine Geology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43007516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Zonation of Marine Geological Environment of Wangi-wangi Island Waters and Adjacent Area Wakatobi Districs Southeast Celebes Province","authors":"A. Haryanto, Y. Darlan, V. Isnaniawardhani, Nisa Nurul Ilmi","doi":"10.32693/bomg.33.1.2018.546","DOIUrl":"https://doi.org/10.32693/bomg.33.1.2018.546","url":null,"abstract":"Wakatobi is one of coastal and marine tourism destination in South–East Celebes Indonesia. Coastal and marine characteristics of this area is composed of diverse biota as the main tourism attraction. Unfortunately, increasing human needs and activities, particularly coral reefs exploitation for construction and other life aspect, endanger the sustainability of marine environment of Wakatobi and the surrounding area. The purpose of this study is to determine marine geology environmental zonation in Wangi–wangi– Kapota Islands, as a consideration for local government in monitoring and regulating the coastal area. The methods that were applied in this study are coastal characteristic mapping, sedimentology, and mineralogy analyses from 34 marine surface sediments. Marine surface sediments have been collected by Marine Geological Institute (MGI) team in 2014. The result indicates that coastal and marine characteristic of Wangi–wangi and Kapota are influenced by geological processes since Middle Miocene. The seafloor morphology is characterized by gentle slopes around coastline that is abruptly changed to very steep slopes seaward. In general, the surficial sediments consisted of biogenic sands that are distributed around coastlines and trapped within coral reefs. Coastal types of this area are generally white coral sand beaches, coral reef platforms, and notches. The area of Wangi–wangi and Kapota can be divided into 4 (four) environmental zone: Flat Plain (Zone I), Sandy Beach (Zone II), Limestone and Coral Reef (Zone III), and Sedimentary Flat (Zone IV). Zone IV in the centre area between Wangi–wangi and Kapota island is considered as the most vulnerable area due to both natural and anthropogenic factor. Keywords: zonation, seafloor morphology, tourism, Wangi–wangi–Wakatobi, Southeast Celebes ProvinceWakatobi adalah salah satu tujuan wisata pantai dan laut yang menarik dikunjungi di Sulawesi Tenggara, Indonesia. Karakteristik pantai dan laut daerah ini disusun oleh keragaman biota laut yang merupakan daya tarik bagi pariwisata. Sayangnya, seiring dengan berkembangnya aktifitas dan kebutuhan manusia, terutama meningkatnya eksploitasi pemanfaatan terumbu karang untuk konstruksi bangunan dan berbagai aspek kehidupan, mengancam kelestarian lingkungan alami Wakatobi dan sekitarnya. Oleh karena itu, penelitian ini dilakukan dengan tujuan untuk membuat zonasi lingkungan pantai dan sekitarnya di Pulau Wangi–wangi dan Kapota, sehingga bisa memberikan pertimbangan bagi pemerintah setempat dalam pengawasan dan regulasi lingkungan kawasan pantai dan sekitarnya. Untuk penelitian ini, metode yang dilakukan adalah pemetaan karakteristik pantai, analisis sedimentologi dan mineralogi yang dilakukan terhadap 34 sedimen permukaan dasar laut. Pengambilan sampel sedimen permukaan dasar laut telah dilakukan oleh Tim Pusat Penelitian dan Pengembangan Geologi Kelautan (P3GL) pada tahun 2014. Hasil penelitian menunjukkan bahwa karakteristik pantai dan laut Wangi–wangi dan ","PeriodicalId":31610,"journal":{"name":"Bulletin of the Marine Geology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41493327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The alteration of vertical distribution of metals in sediment from Flood Canals of Semarang","authors":"F. Budiyanto","doi":"10.32693/bomg.33.1.2018.408","DOIUrl":"https://doi.org/10.32693/bomg.33.1.2018.408","url":null,"abstract":"Semarang Flood Canals distinguished its merit to cope the flood, thus, the observation of sediment quality as one of environmental assessment is required. Those sediments hosted pollutants like heavy metals being a hazard to human. So, the aims of this study were to measure the concentration and to assess the sediment quality based on heavy metal in the flood canals. Responding to the objective, the sediment collection was carried out in April 2016. The collection core sediment samples were carried out up to 80 cm in depth and the sub-sample was collected within 5 cm interval. The laboratory analysis revealed the average concentrations of Cd, Cu, Fe, Ni, Pb, and Zn in the east flood canals were 0,1-0,43; 25,9-36,7; 40.933-76.942; 24,5-35,2; 5,8±13,4; 74,2±113,8 mg/kg dry, respectively. Meanwhile, the concentrations of Cd, Cu, Fe, Ni, Pb, and Zn in the west flood canals were 0,1-0,5; 25,6-59,5; 34.083-76.119; 24,3-33,2; 7,7±22,0; 75,5±173,4 mg/kg dry. East Flood Canal which hosted more intense anthropogenic activities was exhibiting higher metals concentration than West Flood Canal. Enrichment Factor (EF) was computed to assess sediment quality based on heavy metals and the result indicated no enrichment and minor enrichment of metals in the sediment except for Cd and Zn in east flood canal.","PeriodicalId":31610,"journal":{"name":"Bulletin of the Marine Geology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48131683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural complexity in the boundary of forearc basin – accretionary wedge in the northwesternmost Sunda active margin","authors":"M. Mukti","doi":"10.32693/bomg.v33i1.536","DOIUrl":"https://doi.org/10.32693/bomg.v33i1.536","url":null,"abstract":"The area from Andaman to northern Sumatran margin is a region where major faults collided that complicates the structural configuration. The origin of structures in the boundary between the accretionary wedge and forearc basin in the northwesternmost segment of the Sunda margin has been a subject of debates. This article reviews several published works on the Andaman – north Sumatran margin to characterize the boundary between forearc basin and accretionary wedge. Complex strain partitioning in this margin is characterized by sliver faults that crossing boundaries between the backarc basin, volcanic arc, forearc basin, and accretionary wedge. The fault zone can be divided into two segments: The West Andaman Fault (WAF) in the north and Simeulue Fault (SiF) in the southern part. A restraining step-over formed in between WAF and SiF. The SiF may extent onshore Simeulue to a strike-slip fault onshore. Strain-partitioning in such an oblique convergent margin appears to have formed a new deformation zone rather than reactivated the major rheological boundary in between the accretionary wedge and forearc basin. The eastern margin of the Andaman-north Sumatra accretionary wedge appears to have form as landward-vergent backthrusts of Diligent Fault (DF) and Nicobar Aceh Fault (NAF) rather than strike-slip faults. This characteristic appears to have formed in the similar way with the compressional structures dominated the eastern margin accretionary wedge of the central and south Sumatra forearc. Keywords: Andaman, North Sumatra, forearc, structure, accretionary wedge, strain partitioningDaerah Andaman - Sumatera bagian utara adalah wilayah di mana patahan-patahan besar saling bertemu dan membuat konfigurasi struktur menjadi rumit. Asal-usul struktur di batas antara prisma akresi dan cekungan busur muka di bagian paling baratlaut dari tepian Sunda telah menjadi topik perdebatan. Artikel ini mengulas beberapa studi yang telah diterbitkan sebelumnya mengenai tepian Andaman - Sumatra bagian utara untuk mengkarakterisasikan batas antara cekungan muka dan prisma akresi. Pemisahan regangan yang kompleks di tepian ini dicirikan oleh sliver fault yang melintasi batas antara cekungan busur belakang, busur vulkanik, cekungan busur muka, dan prisma akresi. Zona sesar tersebut dapat dibagi menjadi dua segmen, yaitu Sesar Andaman Barat (WAF) di utara dan Simeulue Fault (SiF) di bagian selatan. Sebuah restraining step-over terbentuk di antara WAF dan SiF. SiF kemungkinan menerus sampai ke Pulau Simeulue dan menyatu dengan sesar geser. Pemisahan regangan di tepian konvergen yang miring seperti itu tampaknya telah membentuk zona deformasi baru daripada mengaktifkan kembali batas reologi utama di antara prisma akresi dan cekungan busur muka. Batas bagian timur dari prisma akresi di Andaman – Sumatera bagian utara memiliki bentuk sebagai backthrusts berarah darat yaitu Sesar Diligent (DF) dan Sesar Nicobar Aceh (NAF) dan bukan merupakan sesar geser. Karakteristik ini tampa","PeriodicalId":31610,"journal":{"name":"Bulletin of the Marine Geology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43088971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of Boleng Strait Sediments, East Nusa Tenggara, and its Relationship with Current Velocity","authors":"H. Kurnio, A. Yuningsih, R. Zuraida","doi":"10.32693/BOMG.33.1.2018.387","DOIUrl":"https://doi.org/10.32693/BOMG.33.1.2018.387","url":null,"abstract":"Islands of Nusa Tenggara are separated by narrow and deep straits resulted from complex tectonic activties. One of the strait is Boleng Strait where tidal current as high as 310 cm/s occurred which might be suitable for an ocean current power plant. Utilization of such resources would need various information of the area, one of them is sediment textures that characterized the seafloor and coastal area and their relationship to current velocity. Grain size analyses were conducted on 12 seafloor sediment samples and 26 coastal sediment samples to identify sediment texture. An additonal 14 seafloor sediment samples with limited volume were observed to determine their sediment types. The result of analysis yielded six types of seafloor sediments: Sand, Gravelly Sand, Sandy Gravel, Silty Sand and Sandy Silt. The sediment grain size is equally influenced by current velocity (r = 0.57) and water depth (r = 0.52) which is reflected by sediment distribution: coarse–grain sediments cover the area near Boleng Strait which has stronger current and fine–grain sediments cover the inner part of the Lewoleba Bay. Plot of six sets of mean grain size and current velocity on Hjulström diagram shows that most of seafloor sediments are on the move and one (SBL. 14) is being eroded. This condition might affect the turbine and thus needs to be taken into consideration when designing the turbine. Grain size analyses on coastal sediment samples show that the mean grain size of coastal sediments ranges between 0.19 mm and 0.62 mm with average value of 0.33 mm that is classified as medium sand. Sand fraction in coastal sediments composes 57% to 100% of the sediments. Observation on mineralogy of the sediments shows abundance of magnetite that concentrates in the fine and medium sand fractions. The presence of magnetite indicate that current–related selective entrainment occurs in the study area. This condition suggests that the coastal area is also strongly affected by ocean current.Key words: current velocity, sediment grain size, Boleng Strait.Aktivitas tektonik di Nusa Tenggara Timur menyebabkan terbentuknya batimetri yang kompleks di sekitar kepulauan tersebut yang dicirikan oleh adanya selat sempit dan dalam yang memisahkan pulau–pulau. Salah satu selat tersebut adalah Selat Boleng yang memiliki kecepatan arus terukur maksimum sebesar 310 cm/s yang dapat digunakan sebagai pembangkit energi listrik. Desain turbin arus akan membutuhkan banyak informasi, salah satunya adalah sedimen dasar laut dan pantai serta hubungannya dengan kecepatan arus. Analisis besar butir dilakukan pada 12 sampel sedimen dasar laut dan 26 sampel sedime pantai untuk menentukan jenis sediment. Sebanyak 14 sampel sedimen dasar laut dengan volume terbatas diamati untuk mengetahui jenis sedimen. Hasil analisis menunjukkan bahwa sedimen dasar laut terdiri atas enam jenis: Pasir, Pasir Kerikilan, Kerikil pasiran, Pasir Lanauan dan Lanau Pasiran. Ukuran butir sedimen dipengaruhi oleh kecepatan arus (r","PeriodicalId":31610,"journal":{"name":"Bulletin of the Marine Geology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48637722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oblique Intraplate Convergence of the Seram Trough, Indonesia","authors":"A. Patria","doi":"10.32693/bomg.33.1.2018.553","DOIUrl":"https://doi.org/10.32693/bomg.33.1.2018.553","url":null,"abstract":"The Banda Arc which curves around through 180o is one of interesting features in Eastern Indonesia, a complex area resulting from convergence of Indo–Australia, Eurasia, and Pacific plates with a number of microplates involved. Its complexity has led to debates on how the U–shaped geometry was attained. This study investigates seafloor morphology and seismicity around the Seram Trough which may help to give an insight into the tectonic setting of the area. We further discuss each model proposed for the Seram Trough by previous authors. Generally, there are two views on how many slabs are subducting beneath the Banda Arc, either double slabs or single slab. The Seram Trough, which is often linked to the Timor–Tanimbar Trough enclosing the Banda Arc, was interpreted in different ways, with many models by many authors, as a subduction trench, an intraplate foredeep and a zone of strike–slip faulting. We argue that the most plausible explanation is a single slab model to explain the nature of the Banda Arc. The most plausible model for the Seram Trough is a foredeep model which is associated with exhumation processes on Seram and the deep feature was caused by a subsidence, led by loading by the fold–thrust belt. The Seram Trough is significantly different to common subduction systems. It has shallower bathymetry, is less than 3000 m in depth and is an almost aseismic zone. Keywords: Banda Arc, Buru Basin, convergence, fold–thrust belt, Seram Trough.Busur Banda yang melengkung 180o merupakan fitur menarik di Indonesia bagian timur, suatu area kompleks hasil konvergensi lempeng Indo–Australia, Eurasia dan Pasifik dengan beberapa lempeng mikro terlibat. Kompleksitasnya mengarah pada perdebatan bagaimana geometri ‘U’ terbentuk. Studi ini menginvestigasi morfologi dasar laut dan kegempaan disekitar Palung Seram yang dapat membantu memberikan wawasan tentang tatanan tektonik area tersebut. Kami juga mendiskusikan setiap model yang diajukan untuk Palung Seram oleh beberapa penulis sebelumnya. Umumnya, terdapat dua penjelasan tentang berapa jumlah lempeng yang menunjam dibawah Busur Sunda, antara dua lempeng atau satu lempeng. Palung Seram yang sering dihubungkan dengan Palung Timor-Tanimbar menyelubungi Busur Banda telah diinterpretasikan dengan beberapa model oleh beberapa penulis sebagai palung subduksi, foredeep dalam satu lempeng dan zona sesar mendatar. Kami mengajukan bahwa penjelasan yang memungkinkan adalah model satu lempeng dalam penjelasan keadaan Busur Banda. Model yang dapat diterima untuk Palung Seram adalah foredeep di depan sabuk sesar anjak dan lipatan yang berasosiasi dengan exhumation processes di Pulau Seram dan fitur yang dalam diakibatkan oleh subsidence akibat pembeban jalur sesar anjak dan lipatan. Palung Seram memiliki batimetri yang lebih dangkal, kurang dari 3000m dan merupakan zona aseismik.Kata kunci: Busur Banda, Cekungan Buru, konvergensi, jalur sesar anjak dan lipatan, Palung Seram.","PeriodicalId":31610,"journal":{"name":"Bulletin of the Marine Geology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43930810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sand Distribution Modeling of Middle Miocene Reservoir of “East Tarakan a Field” in Eastern Part of Tarakan Island, East Kalimantan","authors":"Priatin Hadi Widjaja, D. Noeradi","doi":"10.32693/bomg.v26i2.39","DOIUrl":"https://doi.org/10.32693/bomg.v26i2.39","url":null,"abstract":"The discovery well with initial name “East Tarakan A-1” was drilled in February 2007 to a total vertical depth of 10,000 feet and encountered gas reservoir in Middle Miocene-age sands with deltaic sediment facies. The Field is structurally high, faulted to the Mengatal producing zones. This sandstone is hydrocarbon producer in most of onshore fields of Tarakan Island. “East Tarakan A” Field has been suppported with 19 (nineteen) 2D Seismic data. There are three wells i.e: East Tarakan A-1, A2b and A3 with several logs data, mud log and biostratigraphic data. The study aims are firstly to built 3D structural model from time and depth structural maps based on seismic interpretation and well log analysis, secondly to create 3D properties model especially volume shale (V-shale) to get sand distribution. The sand distribution model is supported by 3D structural model, petrophysical analysis and seismic attributes as well as geostatistic method. Based on petrophysical analysis and wells correlation, sand reservoir interval of Middle Miocene (Meliat Fm) can be devided into two zones respectively top to bottom; zone-1 dan zone-2. RMS Amplitude analysis has been used to help constrain the sand distribution. Sand distribution with two zones indicates that sand distribution of zone-1 and zone-2 are generally located in distributary channel delta. NTG Distribution model of zone-1 and zone-2 indicates that reservoir zone distributed in distributary sand with trend of west to east. NTG of zone-1 is relatively better reservoir than the zone-2.","PeriodicalId":31610,"journal":{"name":"Bulletin of the Marine Geology","volume":"26 1","pages":"119 - 134"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69982902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}