Garuda - Garba Rujukan Digital

Article Per Year (5 Year)

All

BULLETIN OF THE MARINE GEOLOGY

bomg
Website

Published by Marine Geological Institute of Indonesia

ISSN : 14106175 EISSN : 25278843 DOI : -

Core Subject : Science,

Earth & Planetary Sciences

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 33, No 1 (2018)" : 5 Documents clear

Structural complexity in the boundary of forearc basin – accretionary wedge in the northwesternmost Sunda active margin Maruf M. Mukti
BULLETIN OF THE MARINE GEOLOGY Vol 33, No 1 (2018)
Publisher : Marine Geological Institute of Indonesia

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 tampaknya terbentuk dengan proses yang mirip dengan struktur-struktur kompresional yang mendominasi bagian timur prisma akresi di daerah Sumatra bagian tengah dan selatan.Kata kunci: Andaman, Sumatera bagian, busur muka, struktur, prisma akresi, pemisahan regangan

Vertical Distribution of Heavy Metals in Coastal Sediment: A Record of the Changing Input in the Estuarine of the Semarang Flood Canal Fitri Budiyanto
BULLETIN OF THE MARINE GEOLOGY Vol 33, No 1 (2018)
Publisher : Marine Geological Institute of Indonesia

Sediment plays an important role in archiving contaminant like heavy metals and couldrecord metal contamination in sediment due to land-based input such as flood canals of Semarang. Thisstudy was to understand the changing record of heavy metals’ contamination in coastal sediment and toassess the sediment quality. Two core sediments, from two different sites, were collected up to 80 cm in depthand, subsequently, sectioned within a 5 cm interval. A digestion system followed by AAS measurement, wasused to determine the metal concentrations, Enrichment Factor (EF) was applied to assess sediment quality.The sediment fraction and metals concentration revealed the changing of input and deposition process alongsediment cores in East Flood Canal (EFC) and West Flood Canal (WFC). There was an alteration ofsediment composition in which the proportion of sediment composition moved to finer size in EFC and apulse of coarser-finer-coarser size of sediment composition was observed in WFC. In general, higherconcentrations of Fe, Cd, Cu, Ni and Zn were observed differently with Pb concentration. Ni along bothsediment cores was unenriched (EF<1), whereas Cd, Cu, Pb, and Zn were classified minor to moderateenrichment. Thus, the source and deposition processes of these Fe, Cd, Cu, Ni and Zn were differentcompared with those of Pb.Keyword: flood canal, Semarang, heavy metal, Enrichment FactorSedimen memiliki peran sebagai tempat penyimpanan bahan pencemar seperti logam berat dan studiatas pencemaran logam berat dalam sedimen di banjir kanal kota Semarang belum banyak dilakukan. Sehinggatujuan dari penelitian ini adalah untuk mengetahui sejarah pencemaran dengan melihat distribusi vertikal kemudianmenilai status logam berat dalam sedimen di muara banjir kanal barat dan banjir kanal timur kota Semarang. Untukmenjawab tujuan penelitian, telah dilakukan pengambilan 2 sampel sedimen inti hingga kedalaman 80 cm kemudiansedimen tersebut diambil tiap interval 5 cm. Metode peleburan yang diikuti pengukuran dengan AAS dilakukanuntuk mengukur konsentrasi logam dan Enrichment Factor (EF) dihitung untuk menilai kualitas sedimen. Fraksisedimen dan konsentrasi logam berat menunjukkan perubahan masukan dan proses deposisi di sepanjang sedimen intiyang dianalsis dari Banjir Kanal Timur (BKT) dan Banjir Kanal Barat (BKB). Tampak adanya perubahankomposisi sedimen dimana sedimen di EFC cenderung menjadi lebih halus sementara tampak adanya fluktuasikomposisi sedimen di WFC dari kasar-halus-kasar. Masing-masing logam menunjukkan pola yang berbedawalaupun konsentrasi Fe, Cd, Cu , Ni dan Zn tinggi tampak di periode energi yang lebih tinggi dan konsentrasi Pbtinggi teramati sema periode energi rendah. Ni di kedua sedimen inti masih berada pada konsentrasi alami(EF<1),tetapi Cd, Cu, Pb dan Zn telah mengalami pengayaan minor hingga moderat. Informasi tersebut dapatmenunjukkan sumber dan proses deposisi Fe, Cd, Cu, Ni dan Zn berbeda dengan Pb.Kata kunci: Banjir kanal, Semarang, logam berat, Enrichment Factor.

Oblique Intraplate Convergence of the Seram Trough, Indonesia Adi Patria; Robert Hall
BULLETIN OF THE MARINE GEOLOGY Vol 33, No 1 (2018)
Publisher : Marine Geological Institute of Indonesia

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.

Zonation of Marine Geological Environment of Wangi-wangi Island Waters and Adjacent Area Wakatobi Districs Southeast Celebes Province Agus Didit Haryanto; Yudi Darlan; Vijaya Isnaniawardhani; Nisa Nurul Ilmi
BULLETIN OF THE MARINE GEOLOGY Vol 33, No 1 (2018)
Publisher : Marine Geological Institute of Indonesia

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 Kapota dipengaruhi oleh proses geologi yang telah berlangsung sejak Miosen Tengah. Morfologi dasar laut dicirikan oleh lereng landai di sekitar tepi pantai dan berubah dengan tegas menjadi curam ke arah laut lepas. Pada umumnya tekstur sedimen permukaan dasar laut terdiri atas pasir biogenik tersebar di sekitar garis pantai, dan mengisi di dalam terumbu koral. Jenis pantai sebagian besar berupa pantai pasir koral berwarna putih, pedataran pantai terumbu koral, serta morfologi pantai berupa takik. Kawasan pantai Wangi–wangi dan Kapota bisa dibagi ke dalam 4 (empat) zonasi lingkungan: Flat Plain (Zona I), Sandy Beach (Zona II), Limestone and Coral Reef (Zona III), dan Sedimentary Flat (Zona IV). Zona IV di area tengah antara Pulau Wangi–wangi dan Pulau Kapota merupakan area yang paling rentan mengalami kerusakan lingkungan akibat faktor alami dan aktifitas manusia. Kata kunci: zonasi, morfologi dasar laut, wisata, Wangi–wangi–Wakatobi, Provinsi Sulawesi Tenggara

Characteristics of Boleng Strait Sediments, East Nusa Tenggara, and its Relationship with Current Velocity Hananto Kurnio; Ai Yuningsih; Rina Zuraida
BULLETIN OF THE MARINE GEOLOGY Vol 33, No 1 (2018)
Publisher : Marine Geological Institute of Indonesia

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 = 0.57) dan kedalaman laut (r = 0.52) yang tercermin pada distribusi sedimen: sedimen berukuran kasar menutupi dasar laut di dekat Selat Boleng yang berarus lebih kuat, dan sedimen berukuran halus menutupi dasar laut di bagian dalam Teluk Lewoleba. Plot enam set ukuran butir rata–rata dan kecepatan arus pada diagram Hjulström menunjukkan bahwa hampir seluruh sampel berada dalam kondisi bergerak dan bahkan satu (SBL. 14) sedang mengalami erosi. Kondisi ini akan mempengaruhi turbin sehingga perlu dijadikan pertimbangan saat mendesain turbin. Hasil analisis besar butir pada sedimen pantai menunjukkan bahwa ukuran butir rata–rata sedimen pantau berkisar 0.19 mm dan 0.62 mm dengan nilai rata–rata 0.33 mm yang termasuk dalam fraksi pasir sedang. Fraksi pasir dalam sedimen pantai menyusun 57%–100% sedimen. Pengamatan mineralogi menunjukkan melimpahnya magnetit yang terkonsentrasi pada fraksi pasir halus–sedang. Keberadaan magnetit menunjukkan adanya proses pemisahan yang berkaitan dengan arus laut. Kondisi ini menunjukkan bahwa daerah pantai Selat Boleng juga dipengaruhi oleh arus laut. Kata Kunci: kecepatan arus, ukuran butir sedimen, Selat Boleng.

Page 1 of 1 | Total Record : 5

Filter by Year

2018 2018

Filter By Issues

All Issue Vol 40, No 2 (2025) Vol 40, No 1 (2025) Vol 39, No 2 (2024) Vol 39, No 1 (2024) Vol 38, No 2 (2023) Vol 38, No 1 (2023) Vol 37, No 2 (2022) Vol 37, No 1 (2022) Vol 36, No 2 (2021) Vol 36, No 1 (2021) Vol 35, No 2 (2020) Vol 35, No 1 (2020) Vol 34, No 2 (2019) Vol 34, No 1 (2019) Vol 33, No 2 (2018) Vol 33, No 1 (2018) Vol 32, No 2 (2017) Vol 32, No 1 (2017) Vol 31, No 2 (2016) Vol 31, No 1 (2016) Vol 30, No 2 (2015) Vol 30, No 1 (2015) Vol 29, No 2 (2014) Vol 29, No 1 (2014) Vol 28, No 2 (2013) Vol 28, No 1 (2013) Vol 27, No 2 (2012) Vol 27, No 1 (2012) Vol 26, No 2 (2011) Vol 26, No 1 (2011) Vol 25, No 2 (2010) Vol 25, No 1 (2010) Vol 24, No 2 (2009) Vol 24, No 1 (2009) Vol 23, No 1 (2008) Vol 22, No 1 (2007) More Issue

Home Page

OAI Link

Editorial Team

Contact

Reviewer

Google Scholar

Contact Name
-

Contact Email
-

Phone
-

Journal Mail Official
-

Editorial Address
-

Location
Unknown,

Unknown

INDONESIA

Abstract

Abstract

Abstract

Abstract

Abstract

Home Page

OAI Link

Editorial Team

Contact

Reviewer

Google Scholar

Contact Name -

Contact Email -

Phone -

Journal Mail Official -

Editorial Address -

Location Unknown, Unknown INDONESIA

Abstract

Abstract

Abstract

Abstract

Abstract

Contact Name
-

Contact Email
-

Phone
-

Journal Mail Official
-

Editorial Address
-

Location
Unknown,

Unknown

INDONESIA