Estimasi Ukuran Bulir Mineral Magnetik pada Batuan Peridotit Berdasarkan Peluruhan Anhysteretic Remanent Magnetization (ARM)

Abstract

A decaying measurement of Anhysteretic Remanent Magnetization (ARM) has been undertaken to estimation the grain size of magnetic mineral which carries remanent on peridotite igneous rocks. The samples are taken from Desa Aranio, Kabupaten Banjar, South Kalimantan. The samples are taken in a cylinder from with the diameter 2.54 cm and 2.2 cm in length by using Drill Model D026-C. The giving, measuring and decaying process of ARM is done by Molspin AF Demagnetizer, partial Anhysteretic Remanent Magnetization (pARM), and Minispin Magnetometer. The estimation of grain size of magnetic mineral is obtained by seeing ARM intensity decaying curve towards magnetic field shown by the samples of peridotite igneous rocks. The ARM intensity decaying curve show that the estimated peridotite rocks in research are dominated by multidomain and the size are big, whereas the distribution of the grain size is larger than 200 μm.

Keywords

• peridotit, anhysteretic remanent magnetization (arm), magnetic grain size, multidomain