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The use of cement materials in construction continues to increase every year, consumes lots of raw material and emits CO2 from clinker production. To eliminate this negative effect, alternative materials are needed. Trass is natural pozzolan which is formed from silica-alumina rich volcanic rocks. As supplementary cementitious material, trass is sufficiently durable and reduce clinker proportion in cement mixture, thus more environmentally friendly. This research aims to determine characteristics and composition of Kedondong trass and Bobos trass, Cirebon, West Java as raw material for pozzolan cement. The study was conducted using petrography and XRD analysis to determine mineralogy of rocks. XRF analysis was carried out to determine chemical composition as well as other tests to determine trass quality. Kedondong trass is originated from andesite intrusion and andesitic breccia, while Bobos trass is formed from hypersthene-andesite intrusion. Based on mineralogy analysis, trasses have similar mineral composition consist of plagioclase, quartz, pyroxene, hornblende, and sanidine. XRD analysis shows abundance of cristobalite and tridymite from each samples. This mineralogy is confirmed by geochemistry result, which is the samples contain more than 70% SiO2 + Al2O3 and less than 4% SO3. Other chemical characteristics that have been tested are moisture content, ignition loss, and clay content in which all of those parameters meet the industrial standard for cement material.

Indonesia was included in the ring of fire so that it has various types of tectonic products, one of which is granitoid. Granitoid is  very complex rock and many are found in Indonesia. Some of them are found in West Kalimantan and Karangsambung. Basis of the reasearch is there is no research that compares granitoid in two regions. The purpose of this study was to compare rock characteristics and granite petrogenesis of West Kalimantan and Karangsambung. The research method used was collecting data on field, also laboratory analysis of rock samples using a polarization microscope, refraction microscope, and X-Ray Fluorescence analysis. The mineralogical characteristics of each study area tend to be almost the same. The predominant composition of the main minerals is quartz, plagioclase and orthoclase. But specifically the rock samples from West Kalimantan have been altered from phylic-silicification-propylitic. The entire study area contained accessory minerals, namely apatite, zircon, titanite, and for monazite only in the West Kalimantan sample. There was mineralization up to the supergene stage in the presence of the characteristic minerals for the supergene covelite and chalcocytes in the West Kalimantan sample. Geochemical analysis of both regions shows the same magma affinity, namely Calc Alkaline - High K Calc Alkaline. For West Kalimantan, the value of A / CNK <1.1 has a type metaluminious and > 1.1 a type peraluminious. Meanwhile, Karangsambung A / CNK value <1.1 has a type metaluminious. So that West Kalimantan granite has two I-type and S-type. While Karangsambung is I-type. West Kalimantan granite is formed in continental arc granite (CAG) and continental collision granite (CCG). Meanwhile, Karangsambung in Volcanic Arc Granite (VAG). It can be concluded that the granites of the two regions have quite different characteristics even though they belong to a relatively similar tectonic environment.