Magnetic Susceptibility of Volcanic Rocks from Pahae Julu Region, North Sumatera Province

Pahae Julu is a sub-district located in North Tapanuli Regency, Sumatra. This area often found with volcanic material from the eruption of Mount Toba (Youngest Tuff). The Youngest Tuff occurred ~74,000 years ago volume 2,800 km3. When there an eruption, lava on earth's surface undergoes relatively fast freezing process to form igneous rock. These rocks contain various minerals, one which magnetic minerals that can be used as track record processes Toba. However, no document records susceptibility value rock area. research aimsbfor knowing abundance by low-field susceptibility. To achieve this goal, magnetism method used. way very effective, cheap, sensitive, and non-destructive. Magnetic measurements are done using Bartington Susceptibility Meter MS2B sensor. Rock samples analyzed pumice result eruption. results showed obtained for sample was between 85.0 x 10-8m3/kg – 183.1 average 119.78 10-8m3/kg. Based value, it assumed mineral properties Antiferromagnetic. χ fd% 0.95%, indicating has almost Superparamagnetic grains.