1,720,978 research outputs found
The Mechanism of Sediment Depositional Environment of Core Drilling of Gilimanuk Coast, Bali and Ketapang, East Java, Based on Sediment Textures
Full text linkThe analysis result of grains frequency curve and relation between grains size to cumulative have shown medium grains at Gilimanuk (Core drilling-1) and coarse grains at Ketapang (Core drilling-2). In general both of them are showed by pattern uniformity, which is represented by the similar of curve pattern. On the grain size of -2 phi as medium gravel with percentage between 6.47 to 35.88%, while core drilling -2 on the size of -2 phi between 6.86 to 61.11%.The average grains size of core drilling -1 are gravel about 21.3%, sand 60.2%, silt 5% and clay about 0.4% while core drilling-2 are characterized by 44.3%, sand 26.8%, silt 24.6% and clay about 0.6%. These result shows that at location of Core drilling -1 is dominated by sand where as at location of Core drilling -2 is dominated by gravel. These situation can be interpreted that the sediment at core drilling -2 location have influenced by strong marine current which can transport the large amount of gravel size compare to the location of Core drilling-1 which is dominated by sand. Based on the relation shape of grains size curve versus cumulative frequency shows that the sediment of Core drilling-1is interpreted as a beach sand deposits and only one sample which shows as a river sand deposits which was found at depth 0 – 3 m depth. In general, the sample of Core drilling –2 shows that the pattern of sediment tend as a beach sand deposits and only one sample which shows the combination between coastal deposits and river deposits ( 4 – 5 m depth). From this sample, the coarse to fine grains is deposited by coastal media and fine grains material (about 10%) is deposited by river media. The sample of river deposits is found as lamination because the only one which is created from combination between coastal and river depos its from all sample of core drilling-2.Keywords: core drilling, grain sediments, media transport, environmental deposition Hasil analisis menggunakan kurva frekuensi butiran serta hubungan antara besar butir terhadap kumulatif menunjukkan dominasi ukuran butiran sedang di daerah Gilimanuk (Bor-1) dan kasar di daerah Ketapang (Bor-2). Pada kedua daerah tersebut, secara umum memperlihatkan pola keseragaman, yang ditunjukkan oleh pola kurva yang sama. Pada ukuran butir -2 phi (kerikil sedang) pada Bor-1 berjumlah antara 6,47 – 35,88%, sedangkan pada Bor-2 pada ukuran -2 phi berjumlah antara 6,86 – 61,11%.Kandungan rata-rata butiran pada Bor-1 adalah: kerikil 21,3%, pasir 60,2%, lanau 5% dan lempung 0,4%, sedangkan Bor-2 adalah: kerikil 44,3%, pasir 26,8%, lanau 24,6% dan lempung 0,6%. Hasil ini menunjukkan bahwa pada Bor-1 didominasi oleh pasir dan pada Bor-2 didominasi oleh kerikil. Hasil ini dapat memberi gambaran bahwa pada Bor-2 berarus lebih kuat karena mampu menstranspor butiran kerikil dalam jumlah yang lebih besar dibandingkan dengan Bor-1 yang didominasi oleh pasir. Berdasarkan beberapa kurva hubungan antara besar butir vs frekuensi komulatif pada Bor-1 menunjukkan endapan pantai (beach sand), hanya satu contoh menunjukkan endapan sungai (river sand), yaitu contoh B1 (0 – 3m). Pada Bor-2, secara umum menunjukkan pola yang lebih mendekati endapan pantai (beach sand), hanya satu contoh menunjukkan kombinasi endapan pantai dan endapan sungai (river sand), yaitu contoh B2 (4 – 5 m). Pada contoh ini, butiran berukuran kasar sampai halus diendapkan oleh media pantai dan ukuran halus dengan persentase sekitar 10% merupakan endapan sungai. Contoh endapan sungai adalah pada B2 (4 – 5 m) ini merupakan endapan sisipan karena satu-satu terbentuk dari kombinasi pantai dan sungai dari seluruh contoh pada Bor-2.Kata kunci: pemboran inti, butiran sedimen, media transport, lingkungan pengendapa
A COMPARISON OF MAJOR ELEMENTS BETWEEN MARINE SEDIMENTS AND IGNEOUS ROCKS: AS A BASIC DETERMINATION OF THE SEDIMENT SOURCE AT UJUNG PENYUSUK WATERS, NORTH BANGKA,BANGKA BELITUNG PROVINCE
Full text linkThree igneous rock samples from the coast and five sediments from the marine of Ujung Penyusuk Waters have been used for chemistry analysis as the basic determination of sediment source. The result of chemistry analysis shows that the major element with relatively same pattern. In the igneous rock samples, the result of chemistry analysis shows the SiO2 ranges between 72.3 - 76.8%, Al2O3 (9.64 - 11.64%), and Fe2O3 ( 2.08 - 2.18%). In the marine sediment, the content of SiO2 is between 62.2 and 66.5%, Al2O3 (2.93 - 3.63%) and Fe2O3 (21.19 - 24.40%). Other elements such as CaO, MgO, K2O, Na2O and TiO2 are relatively similar values in all samples. The difference of element content in marine sediment and coastal igneous rock occurs in Al2O3 and Fe2O3. The Al2O3 is small in marine sediment while the Fe2O3 is higher compared to igneous rocks. Decreasing of the Al2O3 (kaolinite) in the marine sediment is caused by the character of the Al2O3 that was derived from quartz rich of igneous rocks forming kaolinite. It was than deposited in the sea floor. Increasing of the Fe2O3 in marine sediment is caused by addition reaction of the Fe from the sea. Generally, the content of the SiO2 (quartz) in igneous rock and marine sediment belongs to the same group source that is acid igneous rock. The SiO2 in the sediment belongs to a group of granitoid.
Keywords: major elements, marine sediment, igneous rock, Ujung Penyusuk waters
Tiga contoh batuan dari pantai dan lima contoh sedimen dari dasar laut di perairan Ujung Penyusuk, Bangka Utara telah digunakan untuk analisis kimia sebagai dasar dalam penentuan sumber sedimen. Hasil analisis kimia menunjukkan kandungan unsur utama dengan pola yang relatif sama. Pada contoh batuan beku, hasil analisis kimia memperlihatkan kandungan SiO2 antara 72,3 - 76,8%, Al2O3 (9,64 – 11,64%) dan Fe2O3 (2,08 - 2,18%). Pada sedimen dasar laut memperlihatkan kandungan SiO2 antara 62,2 – 66,5%, Al2O3 (2,93 – 3,63%) dan Fe2O3 (21,19 - 24,40%). Unsur lainnya seperti CaO, MgO, K2O, Na2O dan TiO2 yang relatif sama pada seluruh contoh. Perbedaan kandungan pada sedimen dasar laut dan batuan beku di pantai terjadi pada unsur Al2O3 dan Fe2O3. Kandungan Al2O3 pada sedimen dasar laut lebih kecil dan Fe2O3 lebih besar dibandingkan pada batuan beku. Berkurangnya Al2O3 (kaolin) pada sedimen dasar laut disebabkan oleh sifat Al2O3 yang berasal dari rombakan batuan beku yang kaya kuarsa (SiO2) membentuk kaolin. Unsur tersebut kemudian diendapkan di dasar laut. Peningkatan Fe2O3 pada sedimen dasar laut disebabkan oleh penambahan unsur Fe2O3 yang mengikat unsur Fe dari berbagai mineral di laut. Secara umum, kandungan SiO2 (kuarsa) dalam batuan beku dan sedimen dasar laut termasuk dalam kelompok yang relatif sama yaitu batuan beku asam. SiO2 dalam sedimen termasuk kelompok granitoid.
Kata kunci: senyawa utama, sedimen dasar laut, batuan beku, Perairan Ujung Penyusuk
THE GEOCHEMICAL CHARACTERISTIC OF MAJOR ELEMENT OF GRANITOID OF NATUNA, SINGKEP, BANGKA AND SIBOLGA
Full text linkA study of geochemical characteristic of major elelemnt of granitoid in Western Indonesia Region was carried out at Natuna, Bangka, Singkep and Sibolga. The SiO2 contents of the granites are 71.16 to 73.02 wt%, 71.77 to 75.56wt% and 71.16 to 73.02wt% at Natuna, Bangka, and Singkep respectively, which are classified as acid magma. While in Sibolga the SiO2 content from 60.27 to 71.44wt%, which is classified as intermediate to acid magma. Based on Harker Diagram, the granites from Natuna, Bangka and Singkep as a co-genetic. In other hand the Sibolga Granite show as a scatter pattern. Granites of Natuna, Bangka and Singkep have the alkaline-total (Na2O + K2O) between 6.03 to 8.51 wt% which are classified as granite and alkali granite regime. K2O content ranges from 3.49 to 5.34 wt% and can be classified as calc-alkaline type. The content of alkaline-total of Sibolga granite between 8.12 to 11.81 wt% and classified as a regime of syenite and granite. The range of K2O is about 5.36 to 6.94wt%, and assumed derived from high-K magma to ultra-potassic types. Granites of Natuna, Bangka and Singkep derived from the plutonic rock types and calc-alkaline magma, while Sibolga granite magma derived from K-high to ultra-potassic as a granite of islands arc. Based on the chemical composition of granite in Western Indonesian Region can be divided into two groups, namely Sibolga granite group is representing the Sumatera Island influenced by tectonic arc system of Sumatera Island. Granites of Bangka and Singkep are representing a granite belt in Western Indonesian Region waters which is influenced by tectonic of back arc.Keywords: magma, geochemical characteristic, major element and Western Indonesian Region Kajian karakteristik geokimia dari unsur utama granitoid di Kawasan Barat Indonesia telah dilakukan di daerah Natuna, Bangka, Singkep dan Sibolga. Kandungan SiO2 granit Natuna antara 71,16 - 73,02%, Bangka antara 71,77 - 75,56%, Singkep antara 72,68 - 76,81% termasuk dalam magma asam. Granit Sibolga memiliki kandungan SiO2 antara 60,27 - 71,44% termasuk dalam magma menengah - asam. Berdasarkan Diagram Harker, granit Natuna, Bangka dan Singkep mempunyai asal kejadian yang sama (ko-genetik), sedangkan granit Sibolga membentuk pola pencar. Granit Natuna, Bangka dan Singkep mengandung total alkalin (K2O+Na2O) antara 6,03 - 8,51% termasuk dalam jenis rejim granit dan alkali granit. Berdasarkan kandungan K2O antara 3,49 - 5,34 %berat, bersifat kalk-alkali. Granit Sibolga mengandung total alkali antara 8,12 - 11,81% termasuk dalam rejim syenit dan granit, dan berdasarkan kandungan K2O antara 5,36 - 6,94% berasal dari jenis magma K-tinggi sampai ultra-potassik. Granit Natuna, Bangka dan Singkep berasal dari jenis batuan beku dalam dan magma kalk-alkalin yang berhubungan dengan penunjaman, sedangkan granit Sibolga berasal dari jenis magma K-tinggi - ultra-potassik sebagai granit busur kepulauan. Berdasarkan komposisi unsur kimia utama, granit di Kawasan Barat Indonesia dapat dibagi dalam dua, yaitu granit Sibolga yang mewakili P. Sumatera, dipengaruhi oleh sistem tektonik busur P. Sumatera. Granit Bangka dan Singkep dapat mewakili suatu jalur granit di perairan Kawasan Barat Indonesia yang dipengaruhi oleh tektonik busur belakang. Kata kunci: jenis magma, karakteristik geokimia, unsur utama, dan Kawasan Barat Indonesi
THE INCLINATION OF COASTLINE CHANGES AND ITS IMPLICATION FOR LANDUSE MANAGEMENT OF KARAWANG DISTRICT, WEST JAWA PROVINCE
Full text linkResult of observation at 11 locations and the coastline analysis at year map 1990 published by Bakosurtanal and year map 2005 published by Bappeda of Karawang District shows that the existence of changes of the coastline is caused by abrasion and accretion process. The coastal abrasions are occurred in Muarabaru, South Pusakajaya, Cemarajaya and Tanjungpakis areas. The coastal accretions are occurred in Ciparage - Sukajaya, Mekarpohaci, Cemarajaya - South Pusakajaya, East and West Tanjungpakis areas. During the periods of 15 years the abrasions are occurred with the width of 813,171 ha (8,13171 km2) and the coastal long of 30,637 km, and accretions with the width of 1346,22 ha (13,4622 km2) and the coastal long of 43,313 km. Every year the width of abrasion is about 54,21 ha or about 0,5421 km2/year and the width of accretion is about 89,748 ha/year or 0,8975 km2/year. The growth of coastal area about 89,748 ha/year or 0,8975 km2/year. If the coastal management is conducted at the abrasion coasts, the coastal damage can be decreased, and the coastal growth for the productive landuse can be increased.
Keywords: coastline changes, abrasion, accretion, landuse development.
Hasil pengamatan pada 11 lokasi dan analisis garis pantai pada peta tahun 1990 yang dipublikasikan oleh Bakosurtanal dan peta tahun 2005 yang dipublikasikan oleh Bappeda Kabupaten Karawang menunjukkan adanya perubahan garis pantai yang disebabkan oleh proses abrasi dan akresi. Pantai abrasi terjadi di daerah Muarabaru, Pusakajaya Selatan, Cemarajaya, Sedari dan Tanjungpakis. Pantai akresi terjadi di daerah Ciparage - Sukajaya, Mekarpohaci, Cemarajaya - Pusakajaya Selatan dan Tanjungpakis Timur & Barat Selama kurun 15 tahun telah terjadi abrasi seluas 813,171 ha (8,13171 km2) dengan panjang pantai 30,637 km, dan akresi seluas 1346,22 ha (13,4622 km2) dengan panjang pantai 43,313 km. Setiap tahun terjadi abrasi seluas 54,21 ha atau sekitar 0,5421 km2/tahun dan akresi seluas 89,748 ha/tahun atau sekitar 0,8975 km2/tahun. Pertumbuhan kawasan pantai masih lebih besar, yaitu sekitar 89,748 ha/tahun atau sekitar 0,8975 km2/tahun. Bila pengelolaan dilakukan pada pantai-pantai abrasi, maka kerusakan pantai dapat dikurangi dan pertumbuhan pantai untuk lahan produktif masih dapat ditingkatkan.
Kata kunci: perubahan garis pantai, abrasi, akresi, pengembangan tataguna lahan
KANDUNGAN MINERAL PADA SEDIMEN PANTAI DAN LAUT, HUBUNGANNYA DENGAN BATUAN SUMBER DI PESISIR KABUPATEN REMBANG, JAWA TENGAH
Full text linkSedimen di sepanjang pantai Kabupaten Rembang terdiri atas sedimen muda (aluvial) dan sedimen tua (breksi dan batugamping). Sedimen muda merupakan sedimen lepas dan terdapat di daerah sedimentasi. Sedimen tua berupa sedimen kompak yang secara fisik mempunyai resisitensi tinggi terhadap abrasi
Batuan yang terdapat di kawasan pesisir adalah: pasir kuarsa, andesit, tras kaolin, batugamping, batubara dan lempung. Peta sebaran sedimen dasar laut perairan Kabupaten Rembang, menunjukkan dominasi endapan pasir, lanau (pasir halus) dan lanau pasiran (pasir halus - kasar).
Kandungan mineral yang terdapat di perairan Kabupaten Rembang terdiri dari: magnetit, pirit, hematit, zirkon, ilmenit diopsid, augit, hornblende, kuarsa, biotit, muskovit dan dolomit
Kata Kunci: sedimen, mineral, Rembang
The coastal sediment along the coastal of Rembang District consists of young sediment (alluvium) and old sediment (breccias and limestones). Young sediment is placer sediment that occupies the sedimentation area. Old sediment is massive sediment that has a high resistance to abrasion
Rocks content in the coastal zone area consist of quarzt sand, andesite, caoline, limestone, trass, coal and clay. Seafloor surficial sediments map of the Rembang water area shows the domination of sand deposits, silt (fine sand) and sandy silt (fine to medium sand).
Mineral content in Rembang waters area consists of magnetites, pyrites, hematites, zircons, ilmenite diopsides, augitse, hornblendas, quartzs, biotitse, muskovites and dolomites.
Keywords: sediment, mineral, Remban
REKONSTRUKSI PROSES SEDIMENTASI PERAIRAN "LAGOON SAGARA ANAKAN"
Full text linkProses sedimentasi di Laguna Sagara Anakan tidak terlepas dari proses transportasi oleh S. Citanduy. Tetapi jauh sebelum tahun 1944, sebelum sungai-sungai yang lebih muda terbentuk, proses transportasi dan sedimentasi oleh S. Citanduy dengan Daerah Aliran Sungai mencapai bagian utara hingga ke Kabupaten Kuningan - Jawa Barat. DAS Citanduy mencapai 1.675.000 ha (167,5 km2).
Perkembangan garis pantai Laguna Sagara Anakan sejak tahun 1944 hingga 2002 menunjukkan pertumbuhan seluas 64,73 ha per-tahun. Berdasarkan perkembangan tersebut dapat dilakukan prediksi dan rekonstruksi tahapan kedudukan garis pantai hingga stadia terakhir. Jika pada tahun 2002, luas kolam air Laguna Sagara Anakan sebesar 1.596,11 ha dan pada saat stadia akhir proses sedimentasi tinggal 1.065,05 ha maka pertumbuhan daratan mencapai luas 531,06 ha. Bila laju sedimentasi per-tahunnya 64,73 ha, maka stadia akhir sedimentasi Sagara Anakan akan terjadi 8,20 tahun kemudian atau 8 tahun 2,4 bulan sejak tahun 2002. Dengan demikian dapat diprediksi stadia akhir sedimentasi di Sagara Anakan akan terjadi pada tahun 2010.
Sedimentation process in Lagoon Sagara Anakan is not quit of transportation process by S. Citanduy. But far before year 1944, before more formed young rivers, transportation process and sedimentation by S. Citanduy with Catchment Area till to Kuningan District - West Java. Catchments Area of S. Citanduy is 1.675.000 ha (167,5 km2).
Coastline Lagoon Sagara Anakan growth since year 1944 till 2002 showing growth for the width of 64,73 ha per-year. Pursuant to the growth can be predicted and reconstructed step domicile coastline till last stadia. If on 2002, wide of Lagoon Sagara Anakan basin equal to 1.596,11 ha and at the time of final stadia of sedimentation process remain 1.065,05 ha hence growth of coastline 531,06 ha. If accelerateing its sedimentation per-year 64,73 ha, the final stadia of Lagoon Sagara Anakan sedimentation will happened 8,20 year later (8 years 2,4 months) since year 2002. The final stadia of sedimentation can be predicted in Sagara Anakan will happened in the year 2010
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
TINJAUAN GEOLOGI KELAUTAN PERAIRAN SEMENANJUNG MURIA TERHADAP RENCANA TAPAK KONSTRUKSI PLTN
Full text linkSemenanjung Muria terletak di pantai utara Kabupaten Jepara, Provinsi Jawa Tengah. Daerah ini akan dikembangkan menjadi daerah tapak Pembangkit Listrik Tenaga Nuklir (PLTN). Secara geologi, di daerah ini berkembang berbagai fenomena geologi seperti struktur sesar, gunungapi dan kegempaan.
Berdasarkan hasil interpretasi rekaman seismik pantul di perairan Semenanjung Muria menunjukkan adanya struktur sesar pada penampang Lintasan L-1 dan L-3. Struktur sesar tersebut terbentuk pada Sekuen B dan di bawah Sekuen A.
Adanya struktur sesar di laut tersebut perlu mendapat perhatian dalam perencanaan tapak kontruksi PLTN Muria, sehingga aspek yang dapat membahayakan konstruksi dapat diperhitungkan sebelumnya terhadap perencanaan kekuatan dan stabilitas konstruksi.
Kata kunci : sesar, seismik pantul, perencanaan konstruksi, Semenanjung Muria.
Muria Peninsula is located at the north coast of Jepara District, Central Java Province. This area will be developed for the foundation of Nuclear Energy Electrics Powers Station. Geologically, the study area has some geological phenomena such as fault structures, earthquakes and volcanisms.
Based on seismic interpretation the Muria Peninsula waters shows the occurence of faults on L-1 and L-3. The fault structure formed at Sequence B and under Sequence A as a Quaternary sediment.
These faults are seemly the continuation of faults present on land. Therefore, the construction of Muria station should be considered regarding the occurrence of these faults especially in the planning of stability and strength of foundation.
Keyword : faults, reflection seismic, planning of construction, Muria Peninsula
MINERAL CONTENT OF SURFICIAL SEDIMENT OF THE RANGSANG ISLAND AND ITS SURROUNDING AREA, MERANTI REGENCY, ARCHIPELAGO RIAU PROVINCE
Full text linkAccording to the regulation No 4 of 2009 of Mineral and Coal Mining Management stated that the requirement of an inventory for mineral resources data was created to support the establishment of mining area. This study is intended to obtain mineral resources content and surficial sediment data, Geographically the study area belongs to Meranti Archipelago Regency, Riau Province. it is located between 102o00'00" - 103o 15'00" E and 00o35'00" - 01o28'00" N. Grain size analyses result show that surficial sediment in the study area consists of silt, silty sand and sand which is dominated by silt. Based on the mineral identification, some of the minerals such as quartz, cassiterite, magnetite, hematite, dolonite, biotite and zircon have been found. Silt distribution is very wide started from estuarine southeast part northen part of Rangsang Island toward southeast of rangsang island. Sandy silt only found at the southeast of Rangsang Island, while sand sediment is found at the south and southeast of Rangsang Island. The presence of silt and sand grains is influenced by moderate to strong currents and wave patterns, so that the silt and sand grains sediment was transported along coastal to offsore area, while the fine grained (clay - silt) are deposited in the valley at the western part of Rangsang Island.Keywords: mineral, surficial sediment, Rangsang Island Berdasarkan Undang Undang Nomor 4 tahun 2009 tentang Pengelolaan Pertambangan Mineral dan Batubara, disebutkan bahwa inventarisasi data sumber daya mineral diperlukan dalam rangka mendukung penetapan Wilayah Pertambangan (WP). Penelitian ini dimaksudkan untuk memperoleh data kandungan sumber daya mineral dan sedimen dasar laut. Daerah penelitian, secara geografis termasuk dalam Kabupaten Kepulauan Meranti, Provinsi Riau, dan terletak pada koordinat antara 102o00'00" - 103o15'00" BT dan 00o35'00" - 01o28'00" LU. Hasil analisis besar butir menunjukkan sedimen permukaan dasar laut di daerah penelitian terdiri atas lanau, lanau pasiran dan pasir yang didominasi oleh lanau. Berdasarkan identifikasi mineral pada sedimen permukaan dasar lautnya menunjukkan kehadiran mineral kasiterit, magnetit, hematit, dolomit, biotit, zirkon dan kuarsa. Penyebaran lanau sangat luas dimulai dari daerah estuari barat laut dan bagian utara Pulau Rangsang, hingga ke sebelah tenggara Pulau Rangsang. Lanau pasiran hanya terdapat di tenggara Pulau rangsang, sedangkan pasir hanya terdapat di daerah di bagian selatan - tenggara Pulau Rangsang. Adanya butiran lanau - pasir dipengaruhi oleh pola arus dan gelombang yang sedang sampai kuat, sehingga butiran berukuran lanau - pasir dapat terangkut ke arah lepas pantai, sedangkan butiran halus (lempung) mengendap di daerah lembah di bagian barat Pulau Rangsang. Kata kunci: mineral, sedimen permukaan dasar laut, Pulau Rangsan
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