Geochemistry of Natural Gas Seepages in Boto Area, Bancak, Semarang, Central Java

DOI: 10.17014/ijog.4.2.61-70Three seepage gas samples collected from Boto Area, Bancak, Semarang, Central Java, were studied to determine their chemical characteristics using GC and GC-IRMS methods. They are composed 53 - 85% of methane predominantly. However, gas seep Site 3 sample has the highest N2 compound and the lesser extent to the samples Site 2 and Site 1 respectively. The two hydrocarbon gas seeps (Site 1, 2, and Site 3 samples) that are characterized by δ13C methane of -35.61‰ and -27.97‰, and values of δD methane of -112‰ and -109‰ respectively, are each isotopically distinct from all others suggesting, at least, they are derived from different maturity level. The Site 3 gas sample is suggested to be more mature than the others

Indicating the Provenance of Recent Sediment in Yogyakarta Basin from Sediment Geochemistry: Preliminary Results

Recent sedimentation process in Yogyakarta Basin can be represented by the sedimentation by Progo River at the west and Opak River at the east of Yogyakarta. Variation and dispersion characteristic of major element and trace element in the sediment along both river is affected by the provenance. Based on XRF analysis of unconsolidated clastic sediment, it can be indicated that the sediment came from geochemically similar source rock charaterized by abundant major element of Si02, A 1203, FeO and CaO, and trace element of Ba, Sr, and V. The XRD analysis and petrography analysis indicate that the abundant minerals are plagioclase (oligoclase and labradorite) and pyroxene (augite, hypersthenes. enstantite, diopside and pigeonite). The sedimentary material in the upstream area is originally comes from intermediate igneous rock of the volcanic range at north (especially Merapi Volcano), while products of rock weathering from Kulon Progo Mountain Range and Southern Mountain contribute the sedimentary material in the middle up to the downstream area</p

LINGKUNGAN PENGENDAPAN BATUBARA FORMASI WARUKIN BERDASARKAN ANALISIS PETROGRAFI ORGANIK DI DAERAH PARINGIN, CEKUNGAN BARITO, KALIMANTAN SELATAN

Formasi Warukin merupakan salah satu formasi pembawa batubara yang penting di Indonesia. Formasi ini tersingkap dengan baik pada daerah Paringin, Cekungan Barito, Kalimantan Selatan. Penelitian ini bertujuan untuk mengetahui komposisi maseral dan mineral serta tipe paleomire dan lingkungan pengendapan batubara pada daerah penelitian. Berdasarkan hasil analisis petrografi organik, komposisi maseral daerah penelitian didominasi oleh kelompok maseral huminit (52,2-79,8%) dengan kandungan paling banyak berupa subkelompok maseral humotelinit (43,4-72,6%). Kelompok maseral inertinit dan liptinit memiliki kandungan yang rendah berkisar 2,8-18,8% dan 9,8-43,6%. Kandungan mineral pada batubara di daerah penelitian didominasi oleh mineral pirit (0,2-2,2%). Interpretasi lingkungan pengendapan batubara dilakukan berdasar atas analisis petrografi organik dan didukung dengan data analisis stratigrafi yang ada. Hasil analisis ini menunjukkan batubara di daerah penelitian terendapkan pada lingkungan telmatik dengan fasies lingkungan pengendapan berupa lingkungan transisi lower delta plain dan upper delta plain. Hal ini ditunjukkan dengan nilai TPI dan GI yang relatif tinggi serta kesesuaian pola dan komposisi stratigrafi dengan karakteristik lingkungan pengendapan. Tipe atau jenis paleomire berupa wet forest swamp. Gambut pembentuk batubara daerah penelitian bersifat ombrotropik dengan kondisi relatif basah atau lembab. Komposisi vegetasi lahan gambut didominasi oleh tumbuhan kayu atau forest dan terdapat kandungan tumbuhan herbaceous atau marginal aquatic yang rendah

IMPLEMENTATION OF THE INSIDE-OUTSIDE CIRCLE COOPERATIVE LEARNING MODEL ON STUDENTS' COGNITIVE ACHIEVEMENT SDIT AL-IRSYAD

Inside circle learning model has a clear structure and structured, students can work together with peers through mutual cooperation and share information obtained during the learning process. This learning model can improve learning outcomes of learners with the support of learners in the application of learning model inside outside circle. Application of learning model inside outside circle in faith material to qada and qadar can help students understanding that faith to qada and qadar is belief in heart, comprehension which can be expressed by oral, applying by behavior and deed which shows that we believe that destiny of Allah SWT must happen and believe that the efforts we do will not be in vain. With this model students are not only easy to understand the material that the teacher will convey, but will also be able to develop creativity and activities during the learning process

Implementation of the Inside-outside Circle Cooperative Learning Model on Students' Cognitive Achievement Sdit Al-irsyad

Inside circle learning model has a clear structure and structured, students can work together with peers through mutual cooperation and share information obtained during the learning process. This learning model can improve learning outcomes of learners with the support of learners in the application of learning model inside outside circle. Application of learning model inside outside circle in faith material to qada and qadar can help students understanding that faith to qada and qadar is belief in heart, comprehension which can be expressed by oral, applying by behavior and deed which shows that we believe that destiny of Allah SWT must happen and believe that the efforts we do will not be in vain. With this model students are not only easy to understand the material that the teacher will convey, but will also be able to develop creativity and activities during the learning process

Utilizing Coal Remaining Resources and Post-mining Land Use Planning Based on GIS-based Optimization Method : Study Case at PT Adaro Coal Mine in South Kalimantan

Coal mining activities may cause a series of environmental and socio-economic issues in communities around the mining area. Mining can become an obstacle to environmental sustainability and a major hidden danger to the security of the local ecology. Therefore, the coal mining industry should follow some specific principles and factors in achieving sustainable development. These factors include geological conditions, land use, mining technology, environmental sustainability policies and government regulations, socio-economic factors, as well as sustainability optimization for post-mining land use. Resources of the remains of the coal which is defined as the last remaining condition of the resources and reserves of coal when the coal companies have already completed the life of the mine or the expiration of the licensing contract (in accordance with government permission). This research uses approch of knowledge-driven GIS based methods mainly Analytical Hierarchy Process (AHP) and Fuzzy logic for utilizing coal remaining resources and post-mining land use planning. The mining area selected for this study belongs to a PKP2B (Work Agreement for Coal Mining) company named Adaro Indonesia (PT Adaro). The result shows that geologically the existing formation is dominated by Coal Bearing Formation (Warukin Formation) which allows the presence of remains coal resource potential after the lifetime of mine, and the suitability of rubber plantation for the optimization of land use in all mining sites and also in some disposal places in conservation areas and protected forests