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KUALITAS BATUAN BEKU ANDESITIS BERDASARKAN PENDEKATAN KUAT TEKAN DAN PETROLOGI -, Irvan Sophian; -, Aton Patonah; -, Febriwan Mohamad
Bulletin of Scientific Contribution Vol 9, No 3 (2011): Bulletin of Scientific Contribution
Publisher : Fakultas Teknik Geologi Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (686.214 KB) | DOI: 10.24198/bsc.v9i3.8271

Abstract

The quality of infrastructure is related to the materials to be used, especially rock strength. Infrastructure usually uses the rock material as foundation, road materials, etc. Rock samples were taken from Lagadar-Cimahi and Licin-Cimalaka. Petrographic analyses and point load tests were carried out to determine physical and mechanical characteristics. Rock types of Lagadar are andesite and basaltic and Cimalaka are andesite, basalt, and diorite. Rocks of Lagadar are stronger than Licin based on point load test. Point load test of Lagadar rock samples for andesite ranges from 8.17 - 30.57 kg/cm2, basalt ranges from 47.68 -144.03 kg/cm2, and point load test of andesite, basalt, and diorite from Cimalaka ranges between 4.08 - 10.34 kg/cm2, 4.09 -13.83 kg/cm2, and 6.12 kg/cm2 respectively. Rock strength is influenced by mafic mineral content, void ratio, porosity, texture, rock structures, and the degree of weathering.
KARAKTERISTIK BATUAN DAN HUBUNGANNYA DENGAN KUANTITAS & KUALITAS AIR TANAH DI DAERAH CIPUNAGARA DAN SEKITARNYA -, Aton Patonah; -, Sapari Dwi Hadian
Bulletin of Scientific Contribution Vol 11, No 1 (2013): Bulletin of Scientific Contribution
Publisher : Fakultas Teknik Geologi Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1095.901 KB) | DOI: 10.24198/bsc.v11i1.8285

Abstract

Administratively, Cipunagara area is part of Subang Regency, West Java province. Geographically, the research area are located between 107o30’00” – 107o52’30” E and 06o37’30” – 06o52’30” S. Purposes of this research are to know the characterization of water quantity and quality based on petrology and geochemistry methods. The results of this research show that quantities of water depend on porosity. Secondary porosity advanced on basalt and andesite igneous rocks because of deformation. Those conditions give the rocks the ability to reserve much water. Meanwhile primary porosity advanced on tuff and breccia rocks. Based on water geochemistry analysis, the relationship between mineral in igneous rocks (andesite and basalt) that contain cation Ca and water quality can be found. Water in research area contains high cation Ca that good for water drinking 
PETROLOGI AMFIBOLIT KOMPLEK MELANGE CILETUH, SUKABUMI, JAWABARAT -, Aton Patonah; -, Haryadi Permana
Bulletin of Scientific Contribution Vol 8, No 2 (2010): Bulletin of Scientific Contribution
Publisher : Fakultas Teknik Geologi Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (624.82 KB) | DOI: 10.24198/bsc.v8i2.8245

Abstract

Amphibolite is part of Ciletuh mélange complex that was exposed together with serpentinite, harzburgite, dunite, gabro and basalt. The rock is dominated by amphibole and andesine and rarely can be observed quartz. At some locations, the rocks have changed to ampbibolite epidote (oligoclase + hornblende + actinolite + epidote + chlorite). The result of mineral paragenesis and measurement of pressure and temperature indicates that amphibolites was formed of 5 kbar – 6 kbar with temperature 640oC – 660oC. Meanwhile amphibolites epidote was formed of 4 kbar – 5 kbar with temperature 410oC – 455oC. Obtaining pressure and temperature from amphibolites is indicated as result of obduction and then it has retrograded metamorphism to amphibolites epidote because of accretion and uplifting at Upper Oligosen. The indication is characterized by actinolite changed to chlorite, albite and epidote have replaced andesine, and another indication is the rim of hornblende is replaced by actinolite.
LINGKUNGAN TEKTONIK OFIOLIT KOMPLEK MELANGE CILETUH JAWA BARAT BERDASARKAN PENDEKATAN PETROLOGI -, Aton Patonah
Bulletin of Scientific Contribution Vol 9, No 3 (2011): Bulletin of Scientific Contribution
Publisher : Fakultas Teknik Geologi Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1457.431 KB) | DOI: 10.24198/bsc.v9i3.8270

Abstract

The ophiolite sequence of Ciletuh Melange Complex consist of serpentinite, serpentinized harzburgit, dunit, gabro and basalt. Part of the ophiolite partly has been metamorphismed, produce metamorphic rocks. The result of mineral chemical analisis which is supported by geochemical date, the rock shows that the similar character with Duaga Island – Witu Island, Papua Newguinea and Mariana Trench Island arc, that is Island Arc It is signed by the low of forsterite (80-82), there is the existence of magmatic impregnation process, the low Al content in pyroxen showed the increase of degree of partial melting which followed by the increase Si, Mg and Ca content, meanwhile Ti, Cr and Na content decrease followed by the increase degree of partial melting. The ophiolite rock which appear in complex mélange Ciletuh has closed relationship with tectonic setting process which happened in that area. Those approximately happened on Tersier age (Eosen- lower Oligosen), that is accretional is formed in complex mélange Ciletuh, subduction zone move to the west with the direction north-northwest – south-southeast by the appearance of litological, by the present of ultramafics rocks which tectonized and consist of serpentinite and pillow lavas and mixed with sedimen pond. As the same time, also is formed obduction so that result metamorphism process and became metamorphic rock.
PETROLOGY OF HIGH PRESSURE METAMORPHIC ROCKS FROM LUK ULO MELANGE COMPLEX, KARANGSAMBUNG, CENTRAL JAVA-INDONESIA -, Aton Patonah; -, Haryadi; -, Bambang Priadi
Bulletin of Scientific Contribution Vol 7, No 1 (2009): Bulletin of Scientific Contribution
Publisher : Fakultas Teknik Geologi Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (922.829 KB) | DOI: 10.24198/bsc.v7i1.8228

Abstract

Luk Ulo Melange Complex is situated in Central Java, this complex is characterized by the occurrence of Tertiary and Pre-Tertiary rocks as fragments embedded in sheared clay matrix. The fragments consist of ophiolite, metamorphic, chert and carbonate rocks. This research is focused to high pressure metamorphic rock which is represented by glaucophane schist. The rocks consists of albite, augite and ferroaugite, Mg – cataphorite, glaucophane, ferrian and crossite, almandine spesartine, quartz; and rarely can be observed lawsonite, hornblende, tremolite and actinolite. The latter mineral assemblage indicates that the rock was formed at 580oC - 500oC and 14,5 - 4 kbar. Temperature and pressure obtained from glaucophane schist indicated that the rock came from the lower interval of the subduction environment and the possibility have already been in retrograde stage. This is showed by recrystallization of amphibole-glaucophane to sericite or chlorite, and chlorite after garnet. This may represent the retrograde stage in lower temperature-pressure conditions. This data explains the accretion and exhumation history of high pressure metamorphic rocks from subduction depth to the surface condition.