RECENT HEAT FLOW STUDY AND ITS IMPLICATION TO THE GENESIS OF CARBON DIOXIDE IN NORTHEAST JAVA BASIN

摘要

Northeast Java Basin is well known as a prolific petroleum bearing basin with high carbon dioxide concentrations. Heat flow in the area has been studied and presented in heat flow map overlaid by a regional geological structure map and carbon dioxide distibution map. Northeast Java Basin has an average heat flow of 74.18 mW/m~2. The highest heat flow in the area (85-115 mW/m~2) widespreads relatively east-west in northern area of Rembang-Madura-Sakala-Kangean Fault Zone and widespreads relatively north-south along Muria Volcano and Muria Trough sub-basin. On the other hand, the lowest heat flow (20-55 mW/m~2) widespreads relatively north onrtheast - south osuthwest along Bawean Arch. The distribution of high carbon dioxide accumulations in Northeast Java Basin can be grouped into three zones, Bawean Zone (>80%), Muria Zone (25-80%), and Rembang Zone (25-80%). Carbon dioxide accumulations in Muria Zone and Rembang Zone are influenced by higher heat flow (85 mW/m~2 - 115 mW/m~2), whereas Bawean Zone is influenced by lower heat flow (50 mW/m~2 - 85 mW/m~2). This data indicates that the carbon dioxide distribution is related to the heat flow pattern. This supports the hypothesis that the carbon dioxide is dominantly formed by thermal destruction of carbonate rocks.