%A NIM. 11620016 BEKTI AYU LESTARI
%O Nugroho Budi Wibowo, S.Si, M.Sc
%T PEMODELAN STRUKTUR BAWAH PERMUKAAN JALUR
SESAR OPAK DI KECAMATAN PIYUNGAN, BANTUL
DENGAN METODE MAGNETIK
%X Research has been done a modelling the subsurface structure of Opak’s fault
line in Piyungan district, Bantul using magnetic method. This research was aimed
to know the value of magnetic anomaly in the region that indicated as Opak fault
line about Piyungan district and its substructure. The data were taken by Proton
Precession Magnetometer (PPM) type G-856AX using looping method. The
elements of magnetic method analysis were topography correction, daily variation
correction, IGRF correction, polar reduction, upward continuation, and subsurface
modelling. After analysis, we found that magnetic anomaly value of the fault line
is about 640 nT to 80 nT. The anomaly pattern of this fault line has a closure pair
with higher value, i.e. 640 nT to 360 nT at western part accross the lower value,
i.e. 320 nT to 80 nT at eastern part. According to the result interpretation of 2.5D
modelling using Mag2DC software, it can be obtained that the under surface
structure of Opak fault line consist of Young Alluvial formation, Semilir
formation, Kebo Butak formation and Wungkal Gamping formation. The Opak
fault around Piyungan is a normal fault which its western and eastern part are
relatively moving down and at rest, respectively.
%K Sesar Opak, Metode magnetik, anomali medan magnet, struktur
bawah permukaan di Piyungan.
%D 2016
%I UIN SUNAN KALIJAGA YOGYAKARTA
%L digilib14138