Uji Densitas dan Porositas Serta Karakterisasi Batuan Letusan Gunung Semeru di Desa Sumburwuluh Kecamatan Candipuro Kabupaten Lumajang

Abstract

Density and porosity tests are used to test and determine the quality of andesite rock from the eruption of Mount Semeru. Andesite stone is used as a mixture of asphalt in the PG Jatiroto area. The easy collapse of the asphalt road is the main factor in this study. The purpose of this study is to determine the quality of andesite stone through density and porosity tests of stone. The research method used is the expedition method. Stone samples are given treatment (drying, mass measurement, volume measurement and permanent sample) to obtain the density and porosity values of the stone. And observations were made using a mini microscope to see the texture of rocks. Land andesite has an average value of 2.14 grams / ml and river andesite has an average value of 3.04 grams / ml. Based on the description of the analysis of density test data on land andesite and river andesite has the same quality, which is good. Land andesite has an average porosity value of 31.2% and river andesite has an average porosity value of 32.9%. Judging by the average value of porosity, the rocks are of excellent quality. The final result of the porosity value is inversely proportional to the rock density value, that is, the porosity value of the rock is greater than the rock density value. This andesite stone contains a lot of silica due to its bright wara. The degree of crystallization of the rock is composed of crystals that are imperfect or irregular in shape. The constituent grains of the rock also have unequal sizes. The density value affects the quality of Mount Semeru eruption rocks. The porosity value affects the quality of Mount Semeru eruption rocks. The characterization of the eruption rocks of Mount Semeru analyzed is andesite (extrusive rock). The stone has the characteristics of light gray color, the constituent minerals are anhedral and the shape of the constituent grains is almost the same (equigranular). While andesite stone is composed of crystalline minerals whose constituent minerals are large.