HR: 1330h
AN: G32A-0740    [PDF]
TI: Gravity study in the Taipei Basin
AU: * Hsieh, H
EM: alvo@escc.gep.ncu.edu.tw
AF: Institute of Geophysics, National Central University, NO.300, Jung-da Rd., Jung-li, 320 Taiwan
AU: Yen, H
EM: yenhy@earth.sinica.edu.tw
AF: Institute of Geophysics, National Central University, NO.300, Jung-da Rd., Jung-li, 320 Taiwan
AU: Lu, M
AF: Chinese Petroleum Corporation, 3, SUNGREN ROAD, SHINYI CHIU, Taipei, 110 Taiwan
AU: Wang, C
EM: wangcy@earth.ncu.edu.tw
AF: Institute of Geophysics, National Central University, NO.300, Jung-da Rd., Jung-li, 320 Taiwan
AB: Taipei City is a metropolis in northern Taiwan, which is located on a triangle-shaped alluvium basin. Gravity measurement and analysis are particularly useful as a reconnaissance tool for an urban region. A higher resolution gravity map over the Taipei Basin is required to help understand its tectonic signature. There is, therefore, a need to compile a gravity map that encompasses the entire basin region. In this study, we have compiled the gravity data (roughly 36 km x 36 km) of the Taipei Basin and its surrounding area. After gravity reductions, the Bouguer anomaly map was constructed. The general trend of the Bouguer values decreases from west to east, but does not reflection the basement structure of the Taipei Basin. The residual anomaly is obtained by using Griffin method to investigate the shallower structure. We also calculate the derivative anomaly map to analyze some high frequency signal of the Taipei Basin. The shallower sedimentary layer is almost flat referred from above both maps. To illustrate how the gravity data constrain subsurface density structures, a two-dimensional gravity analysis will be performed with the gravity profile across the geological strike taken from the Bouguer anomaly map. In the modeling, available seismic, drilling, and other data are used wherever possible to constrain the geometries and/or densities. Preliminary results of the modeling and their geological significance will be presented.
DE: 1219 Local gravity anomalies and crustal structure
DE: 8105 Continental margins and sedimentary basins
SC: Geodesy [G]
MN: 2003 Fall Meeting