Using 3D seismic and well data, detailed seismic interpretation has been conducted on two carbonate Platforms EX and FY located in the Central Luconia Province, Malaysia. The results provide an insight to understand the relationship of faulting with syn-depositional carbonate growth. Five geo-seismic units were interpreted from the Late Oligocene to present day sedimentation in the basin. Structural interpretation of both platforms shows that almost all the faults in the deeper part of the platforms are normal listric faults that resulted from the final rifting stage of the South China Sea. Small-scale, steep normal faults within the carbonate units behave relatively as syn-depositional faults that became the base and template for the reefs to grow as these faults created conjugate and branching faults systems. Apart from becoming templates for the reefs to grow, these syn-depositional faulting events had also interrupted the growth of reefs especially those that were located at the platform margin. Slight movement of the branching faults induced sub-marine landslide to create reefs collapse. The establishment of relationship between faulting and carbonate growth in Central Luconia Province might be useful for revisiting mature hydrocarbon reservoirs.

No abstract

Using high quality regional seismic lines, we evidence major structures resulting from successive phases of tectonic events that affected the Luconia shelf from the Upper Cretaceous to Pliocene. Each tectonic event (Classified as Event 1–Event 3) is associated with different episodes of limestone growth in Luconia Province. The successive limestone growths are used as markers in constraining the timing and style of tectonic deformation. The poly-stage closure of the Proto South China Sea (PSCS) from the Upper Cretaceous to Lower Miocene led to the formation of compressional structures in its southern portion (South PSCS) providing elevated topography for the growth of the oldest limestone found in this area during the Upper Eocene to Lower Oligocene (Event 1). Based on contrasting seismic reflectors, morphology, and depositional patterns, the offshore Upper Eocene-Lower Oligocene limestone growth is correlated to the onshore Engkabang-Karap limestone. The southern part of Luconia was subjected to a continuous compression until the Lower Miocene at a time where the northern side of the Luconia Province was experiencing subsidence due to the rifting of the South China Sea (Event 2). The compression in the south generated elevated anticlines, triggering the growth of the Upper Oligocene to Lower Miocene limestone. By the end of the rifting event in the Lower Miocene, tectonic quiescence had enabled widespread carbonate growth in Luconia from the Middle to Upper Miocene. Regional compression due to the major uplift of Borneo hinterland (Event 3) triggered paramount clastic influx (gravity tectonics) to the offshore perturbating the limestone reef growth in Luconia. The impact of these interrelated shortening and stretching phases led to major crustal thickness variations and a prominent tilt of the Luconia platform that may highlight intricate feedbacks at the transition from compression to extension. While the southern side of the Luconia’s crustal fragment was anchored into Borneo hinterland, crustal extension in the northern region of Luconia led to a hyper-stretched crust characterized by low angle detachment faults and highly rotated blocks rising the mantle to its shallowest.

No abstract

No abstract