12 sumberdaya geologi
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Materi GeologiTRANSCRIPT
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TGD 1102TGD 1102GeologiGeologi
12. Sumberdaya Geologi12. Sumberdaya Geologi
Salahuddin HuseinSalahuddin Husein
Jurusan Teknik GeologiJurusan Teknik GeologiFakultas Teknik Universitas Gadjah MadaFakultas Teknik Universitas Gadjah Mada
20112011
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shddin © 20111. Konsep• Sumberdaya mineral terkonsentrasi oleh proses geologi yang beroperasi
dalam sistem tektonik dan hidrologi. Sebagian besar membutuhkan waktu yang lama untuk terbentuk, sehingga bersifat terbatas dan tidakterperbaharui.
• Endapan mineral (ore deposits) dibentuk bersama proses pembentukan batuan beku, sedmen, metamorf, dan proses pelapukan. Banyak pula mineral logam yang melibatkan pergerakan fluida hidrotermal.
• Sumber energi yang bersifat tidak terperbaharui meliputi batubara, minyak dan gas bumi, dan energi nuklir. Sumber energi yang terperbaharui meliputi energi panas matahari, tenaga angin, tenaga air, tenaga pasang-surut, dan energi panasbumi. Saat ini energi terperbaharui hanya menyediakan sedikit dalam kebutuhan energi manusia.
• Lokasi dan kekayaan sumberdaya alam ditentukan secara langsung maupun tidak langsung oleh tektonika lempeng.
• Ada batas pertumbuhan populasi manusia yang ditentukan oleh keterbatasan sumberdaya alam.
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shddin © 20112. Sumberdaya Mineral
Proses geologi dalam pembentukan sumberdaya mineral
shddin © 20113a. Sumberdaya Mineral Bentukan Batuan Beku
Sebaran endapan mineral bijih menurut tatanan tektonik.
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Pembentukan batuan beku menghasilkan banyak endapan mineral.
3a. Sumberdaya Mineral Bentukan Batuan Beku
Beryllium Lithium
gold, silver, copper, lead,
zinc
iron, tungsten
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Krom (chromite) terbentuk dari kristalisasi dan pengendapan lantai intrusi batuan beku basa. Bushveld Complex, South Africa.
3a. Sumberdaya Mineral Bentukan Batuan Beku
chromite
olivine
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Endapan tembaga terbentuk dari intrusi dangkal yang melibatkan fluida hidrotermal. Bingham, Utah.
3a. Sumberdaya Mineral Bentukan Batuan Beku
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Grasberg, Papua
3a. Sumberdaya Mineral Bentukan Batuan Beku
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shddin © 20113a. Sumberdaya Mineral Bentukan Batuan Beku
Grasberg, Papua
shddin © 20113b. Sumberdaya Mineral Bentukan Batuan Metamorf
iron, tungsten
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Emas, intan, dan timah, umumnya ditemukan sebagai endapan tempatan di sepanjang alur sungai.
Konsentrasi mineral logam berat dalam endapan tempatan (placer deposits) oleh aliran sungai.
3c. Sumberdaya Mineral Bentukan Batuan Sedimen
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Formasi Besi Berlapis (banded iron formations) terbentuk ketika mineral besi berselingan dengan rijang terendapkan di lingkungan laut dangal Pre-Kambrium.
3c. Sumberdaya Mineral Bentukan Batuan Sedimen
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Penguapan yang sangat tinggi akan menghasilkan garam dan magnesium.
3c. Sumberdaya Mineral Bentukan Batuan Sedimen
Petani Garam, Madura
shddin © 20113c. Sumberdaya Mineral Bentukan Batuan Sedimen
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shddin © 20113d. Mineral dan Proses Pelapukan – Pelarutan
shddin © 20114. Sumberdaya EnergiEnergi yang dikonsumsi oleh USAdisediakan dari banyak sumber.
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Perkiraan konsumsi minyakbumi di USA (M. King Hubbert, 1956)
4. Sumberdaya Energi
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Prediksi konsumsi energi dunia
4. Sumberdaya Energi
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shddin © 20114a. Sumberdaya Energi TerbarukanEnergi panas matahari
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Tenaga air.Hoover Dam, Colorado River.
4a. Sumberdaya Energi Terbarukan
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Tenaga angin
4a. Sumberdaya Energi Terbarukan
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Energi panasbumi
4a. Sumberdaya Energi Terbarukan
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Lapangan Panasbumi Wayang Windu, Pengalengan
4a. Sumberdaya Energi Terbarukan
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Air panas terbentuk akibat sirkulasi airtanah di sepanjang sesar yang dalam atau terpanaskan oleh tubuh intrusi magma dangkal.
4a. Sumberdaya Energi TerbarukanSistem panasbumi
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shddin © 20114b. Sumberdaya Energi Tidak TerbarukanCoal deposits are commonly formed by the expansion and contraction of a shoreline and involve the associated movement of a swamp and barrier bar.
shddin © 20114b. Sumberdaya Energi Tidak Terbarukan
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The origin of coal involves burial, compaction, and induration of plant material.
4b. Sumberdaya Energi Tidak Terbarukan
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The principal coal deposits are concentrated in fluvial and deltaic sedimentary rocks on the continental platforms.
4b. Sumberdaya Energi Tidak Terbarukan
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Panian Coal Mine, Semirara Island, Philliphine
4b. Sumberdaya Energi Tidak Terbarukan
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The accumulation of oil and gas requires (1) a reservoir rock (a permeable formation, such as a porous sandstone) into which the petroleum can migrate and (2) a barrier (an impermeable cap rock) to trap the fluids.
Anticline. Oil, being lighter than water, migrates up the dip of permeable beds and can be trapped beneath a relatively impermeable shale bed in the crest of an anticline.
4b. Sumberdaya Energi Tidak Terbarukan
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The accumulation of oil and gas requires (1) a reservoir rock (a permeable formation, such as a porous sandstone) into which the petroleum can migrate and (2) a barrier (an impermeable cap rock) to trap the fluids.
Fault trap. Impermeable beds can be displaced against a permeable stratum and then trap the oil as it migrates up dip.
4b. Sumberdaya Energi Tidak Terbarukan
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The accumulation of oil and gas requires (1) a reservoir rock (a permeable formation, such as a porous sandstone) into which the petroleum can migrate and (2) a barrier (an impermeable cap rock) to trap the fluids.
Salt dome. Oil and gas may accumulate near the flanks of salt diapirs that pierce and arch up sedimentary layers.
4b. Sumberdaya Energi Tidak Terbarukan
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The accumulation of oil and gas requires (1) a reservoir rock (a permeable formation, such as a porous sandstone) into which the petroleum can migrate and (2) a barrier (an impermeable cap rock) to trap the fluids.
Stratigraphic trap. Shale surrounding a sandstone lens can form and prevent the oil from escaping.
4b. Sumberdaya Energi Tidak Terbarukan
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Three-Dimensional Seismic Imaging
4b. Sumberdaya Energi Tidak Terbarukan
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Major oil and gas fields and deposits of oil shale are found on all of the continents except Antarctica. Most form in thick sedimentary deposits on continental crust.The rifted margins of Africa, South America, and Europe are important oil-producing environments.Other important fields lie in the sedimentary basins of the platform and the flanks of folded mountain belts.
4b. Sumberdaya Energi Tidak Terbarukan
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Oil wells such as this in the North Sea are important symbols of our modern society
4b. Sumberdaya Energi Tidak Terbarukan
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Anjungan Pengeboran Minyakbumi Lepas Pantai
4b. Sumberdaya Energi Tidak Terbarukan
shddin © 20114b. Sumberdaya Energi Tidak Terbarukan
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Methane hydrates consist of a methane molecule (CH4) trapped inside a crystalline “cage” of frozen water (left).They form on the deep seafloor as methane released by bacteria bubbles upward and is trapped in ice.They may be abundant enough to form an important source of natural gas and will burn if ignited with a match (right). However, they will be difficult to mine and pose environmental hazards because methane is a greenhouse gas.
4b. Sumberdaya Energi Tidak Terbarukan
shddin © 20114c. Energi NuklirUranium deposits and nuclear reactors may become a key part of the future production of energy, but only if the public becomes convinced that nuclear reactors are safe and that their waste products can be safely stored in repositories for long periods of time.
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shddin © 20115. Tektonika Lempeng dan Sumberdaya MineralMineral resources are intimately related to the plate tectonic system. Some of the major ore-forming environments are shown on this schematic cross section. Plate tectonics controls igneous, sedimentary, and metamorphic processes and even the climate; it therefore exerts a major control on the types of ore deposits formed at any location and time.
shddin © 20116. Batas Pertumbuhan dan KonsumsiEarth’s human population has grown exponentially.
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A computer model of resource consumption and its influence on other variables assumes no major changes in the physical, economic, and social relationships that historically have governed the development of the world system.
6. Batas Pertumbuhan dan Konsumsi
shddin © 20117. Pulau Easter
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shddin © 20117. Pulau EasterPollen fossilsrecords.