| Neogene Baram Delta is located in the northwest Borneo, which is characterized by different structural styles in the northern, the middle and the southern parts respectively, owing to being on the active continental margin. Affected on compression stress, NE-SW striking imbricate thrusts develop in the northern part. Influenced by extension stress, NE striking growth faults and associated rollover anticlines develop in the middle part while the inversion structures generated by compresso-shearing develop in the southern part. It has been confused by the fact why the total shortening amount in the compression area (i.e. the northern part) is greater than the total stretching amount in extension area (i.e. the middle part) , which has been unable to be explained by the ideal model of delta system in the passive margin. Based on the regional tectonic setting and basin stress analysis and the structural restoration, it is shown that accompanied with far-field regional compression that rises from pushing by Philippine Plate, Indo-Australian Plate and Eurasia Plate, the gravitational drive during delta growing has resulted in the comprehensive process, which is regarded as the reason. |
