## 5 Results
### Depth Estimation for Signature Patterns
The interception point for the depth profiles and seismic lines are pointed by black arrow at the top of images in **(B–F)**. stratigraphic layers at depth \(-4000\) ms to \(-8000\) ms which include sediments in Cycle I and older. Thus, the NE-SW trend is suggested to represent deep normal faults that were active during Eocene-Cretaceous and offsetting Cycle I-II and Pre-Cycle sediments. Profile Y-Y\" (Figure 12B) exhibits undulating, yet consistent shallow anomalies and is compared with parallel seismic line 1008 (Figure 12C). The computed shallow anomalies on Y-Y\" profile are satisfactory with the morphology of the top carbonate of Cycle IV or V, but the longer wavelength solution seem to be more uncertain. The depth profiling from short and long wavelengths were indeed unconstrained at the time that the data were extracted. Thus, the depth profiles are representative of succession of horizon and not limited to one single horizon, as what usually interpreted on seismic data. Depth profile Y-Y\" is perpendicular with majority of the NW-SE structural trends interpreted on aeromagnetic and airborne gravity maps (Table 2). Majority of the faults associated with Cycle III and younger sediments on seismic line 1008 are striking in NW-SE directions (Figure 12D). Thus, the NW-SE faults interpreted by the aeromagnetic and gravity data might represent faults that affecting the Miocene sediments of Cycle III-VIII. The NW-SE trend is also parallel to the orientation of two main structural features that bounded Central Luconia Province, which are the West Baram Line and West Balingian Line (Figure 1C). Similar features seen on both profiles with their neighboring seismic lines are pointed with arrows on Figure 11B-F and Figure 12B-D. Shallower structures captured by short wavelength (orange arrows) match very well with either the Top of Cycle IV/V limestone, including the flat-top or pinnacle shape build-ups as delineated on the seismic. Deeper structures captured by long wavelength represent structures at the Top of Cycle I or Cycle II which are interpreted as uplifted topography that are faulted, and some are compressed  
Figure 12: (**A**) Location of depth profile Y-Y” and seismic line 1008. (**B**) Depth profile Y-Y”. (**C**) Uninterpreted section of seismic line 1008. (**D**) Interpreted section of seismic line 1008. The blue and orange arrows are pointed to similar geological features interpreted on the depth profile and the seismic data. The seismic lines are marginally longer that profile Y-Y’ and change its orientation to NE-SW direction. The intersection points where both data are comparable is marked by the black arrows. The dash-line rectangles in (**C**,**D**) is to point out the section of circular structure/depressional area in Figure 11B. due to extensive faulting. These structures are observed at depth between \(-4000\) and \(-6000\) ms (equivalent to \(-2000\) to \(-3000\) m). With good correlation between geometry of structures interpreted on depth profiles X-X' and Y-Y' with nearby seismic lines, the amplitude strength on the Tzz, Txz and Tyz gravity response (Figures 8 and 9) are adjudged to represent the top of Cycle IV and or Cycle V limestone since amplitude strength points to the density of the carbonate fill (i.e., porosity of the carbonate rocks) as suggested by [54]. Cross examination with the sonic and density logs for Lada Hitam-1 and F6-6 well reveals average porosity of 20-22% in Cycle IV and V limestone and bulk density of 2.36 g/cm\({}^{3}\) in the formation. The clastic sediments of Cycle VI- VII overlying the limestone have average porosity of 31.54 to 33.7% and average bulk density of 2.09 g/cm\({}^{3}\). Variations in the density of the formations provide accurate position to map the top of limestone interpreted in the depth profiles extracted from the airborne gravity data.