PREDIKSI BATAS CEKUNGAN JAWA TIMUR UTARA DENGAN PEGUNUNGAN SELATAN DI DAERAH MAGETAN - PLAOSAN DENGAN METODE GRAVITASI
ABSTRACT: Geophysics
investigation with the gravity method to antisipate the existence of
boundary of North East Java Basin with
the South Mountains in Magetan - Plaosan have been done at 2 – 11 December 2004
by using gravitymeter La Coste & Romberg type G-I177, and resulted 50
station. Data measured field is the observation gravitation position height and
terrain conection for A until D zone. To obtain the complete Bouguer anomaly,
reduction of field data was performed with standart correction. Bouguer density of rock is
obtained 2,30 gram/cm3. Regional and residual anomaly was obtained from
filtering of complete bouguer anomaly by using polynomial surface fitting. The
quantitative analysis of second order residual anomaly was performed by using
Grav2DC for windows. The modelling resulted Lawu lava with density 2,35
gram/cm3 and culminate deepness is 300 m, Tuf Jobolarangan with density 2,20
gram/cm3 and culminate deepness is 300 m, sediment rock with density 2,10
gram/cm3 and culminate deepness is 123,84 m, Igneous rock with density 2,70
gram/cm3 and culminate deepness is
1.721,53 m. Basin boundary marked with the exsistence of sediment rock
and igneous rock in subsurface of the area. Interpretdion of modelling indicate
that Magetan - Plosan area anticipated to represent the south boundary of North
East Java Basin with the South
Moantains.
Penulis: Dewi Wijayanti, Rr.
Tony Yulianto, M. Irtem Nurwidyanto
Kode Jurnal: jpmatematikadd090073
