8/17/2019 Resume Discussion.docx

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Resume Discussion

Bandung and Garut basin are two depression zones which are pyroclastic deposit that

almost all over around the basin and the younger lava deposit that separate those two basins. The

 pyroclastic deposit associated with high Bouguer anomaly and the younger lava associated with

low Bouguer anomaly.

The preliminary data showed two possible stages of evolution of the study area. First

stage was the one related to the older pyroclastic spreading, and the second stage was the one

related to the basin structure and younger volcanic activity.

agnetotelluric were measured along the two lines across Bandung!Garut basin that

crossed the two closures of low Bouguer gravity anomaly. The low resistivity areas that appear 

near the surface were associated with loose sediment. The intermediate resistivity roc"s

associated with sediment deposit and felsic igneous roc". #nd high resistivity roc"s associated

with hard sediment deposit or igneous roc". The highest resistivity layer associated with older igneous roc" or basement.

The models indicate the e$istence of at least two stages of tectonic process in this area.

First, there was an e$tension regime that produced the formation of horst and graben. #t second

stage, the e$tension force ceased that made it possible for the formation of horizontal layering,

which covered the area that continuous until most recently although there is upset that indicates a

normal fault. There is possibility that the e$tension force reappeared recently and formed the

normal fault.

The subsurface models ac%uired could not e$plain further in term of the wide area of 

Bandung zone because two lines surveys are too little to cover the tectonic study of the area.