Publications

Subsurface structure interpretation of the eastern South Serayu Basin has been conducted using GGMPlus v.2013 gravity data. There is some evidence that biogenic gases are discharging at the southern part of the basin. At least five sites of gas discharges are reported. Nevertheless, the rock formation as the source of these gases are still unknown. The availability of GGMPlus v.2013 gravity data which was modelled from satellite data gives an opportunity to interpret this basin and determine the source of these gases. This research is conducted by processing gravity disturbance and free fall acceleration of GGMPlus v.2013 gravity data. The final result of these processing steps is a map of complete bouguer anomaly in a flat plane. After that, the effect of regional anomaly is being separated from residual through a low-pass filter. The residual anomaly is being used to analyze the basin boundary, while the regional anomaly is used to construct 2.5D forward modelling crossing against the basin in west-east (W-E) sections. The analysis result is then used to identify the subsurface structure of the basin. The residual anomaly indicates that the basin has a boundary which is identical with the geological pattern of South Serayu Mountain. This informed us that the basin has shallow gravity anomalies which vary according to geological features. Meanwhile, the result of the regional anomalies model shows that this basin has a basement that goes deeper to the north. These results provide conclusions that the gas discharges are shallow biogenic gases which came from shallow rock formation of the basin.