## 5 Results  
### Aeromagnetic & Airborne Gravity Interpretation  
#### 5.1.1 Aeromagnetic Interpretation  
The interpretation of aeromagnetic data primarily reflects long wavelength (deep) geophysical features in the subsurface. High magnetic anomalies (>20 nT) from TMI_RTE fall in the northern-central section of the survey area while moderate magnetic anomalies (0 to 20 nT) (Figure 5A) are observed at the central section of the survey. The lowest magnetic anomaly (0 to \(-\)68 nT) is seen in the south and southeast parts of the survey area which include the West Luconia-Balingian Provinces (see location map in Figure 1). The southern part of the survey area exhibits an obvious low magnetic response (0 to \(-\)68 nT) on both TMI_RTE and TMI_RTE_1 vd anomalies maps which appears elongated in the E-W direction. The first vertical derivative characterizes shallow anomalies (short wavelength) compared to its original TMI_RTE data. Thus, the low magnetic zone in the south of the survey area is occupied by small-scale, elongated high magnetic zones in the shallower section, as imaged on TMI_RTE_1 vd data (Figure 5D,E). Comparable trends of dominant NE-SW and NW-SE with auxiliary E-W are seen on both TMI_RTE and TMI_RTE_1 vd datasets indicating magnetic basement structures (interpreted on TMI_RTE) imprinted on the shallower magnetic structures interpreted on the TMI_RTE_1 vd map. WNW-ESE to E-W trends are interpreted on TMI_RTE_1 vd. An evaluation of both TMI_RTE and its derivatives maps reveal some structural features become more outstanding either on the TMI_RTE data or TMI_RTE_1 vd data (pointed out by the red arrows). This illustrates contrasting structures between the magnetic basement (seen on TMI_RTE map) and the shallower depths (TMI_RTE_1 vd map). For instance, remarkable E-W trends are visible between two major elongated structures in the south of the survey area on TMI_RTE_1 vd map but are not seen on the TMI_RTE map (rectangle zone in Figure 5E). Another example is highlighted in Figure 5B,E, where very curved features are seen on TMI_RTE (magnetic basement) but no longer appear on the TMI_RTE_1 vd. Some other lineaments that are only seen on either the magnetic basement or shallower section are pointed by the red arrows on Figure 5B,E. Further analyses on the analytical signal data of the aeromagnetic data are conducted to reduce the uncertainty in interpreting magnetic data at low latitude such as in Central Luconia Province. A careful examination of the regional aeromagnetic map indicates that some of the magnetic anomalies detected on original TML_RTE map are appearing on the regional analytical signal maps (Figure 6A,D) with lower amplitude and frequencies. A similar NW-SE structural trend is preserved both in TMI_RTE and regional aeromagnetic map from the analytical signal. However, the magnetic anomalies on regional analytical signal appear in lower amplitude compared to the TMI_RTE anomalies. The regional analytical signal is characterized by a main trend striking NNW-SSE to E-W with a minor NW-SE for both less than 20 and 50 km wavelength. The residual analytical signal anomalies for these two wavelengths show clusters of elongated bodies of high magnetic response within low magnetic values in the southern part of the survey area, striking E-W.  
Figure 5: (**A**) Total Magnetic Intensity Reduce to Equator (TMI_RTE) represents magnetic basement. (**B**) Lineaments/Structural trend interpretation on TML_RTE. (**C**) Rose plot diagram for interpreted structural trend in (**B**). The eclipse on (**B**) is representing possible folding structures on the basement (obvious anticline closure on TMI_RTE. (**D**) First derivative of TMI_RTE known as TMI_RTE_1 vd represents section shallower than the basement. (**E**) Lineaments/ Structural trend interpretation on TMI_RTE_1 vd. (**F**) Rose plot diagram for interpreted structural trend in (**E**).