## 5 Discussion
### Implications of Submarine Channels' Morphologies for Paleoenvironment Interpretation  
The increase in morphometric parameters, together with the high correlation (R) and determination (R\({}^{2}\)) coefficients (Table 1) from the western to the eastern areas, suggested that the movement of the channels is induced by gravity, and the net transport from these currents are primarily in a seaward direction [5; 19; 59]. Furthermore, based on the classification of [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] [54], [PERSON], [PERSON] and Auchter [55], and [PERSON] and Mahender [61], the scaling relationship of the channel's morphometry elements in the study area is characterized as a submarine environment. In addition, biostratigraphy data from Galleon-1 wellbore at the corresponding intervals show the presence of _Euuvigerina rodeleyi s.l., Euuvigerina miozea s.l., Notorotalia Hrupiensis_, and _Hopkinina Mioinder_. This indicates a marine environment with an increase in water depths and turbid conditions followed by a rapid rate of sedimentation [45; 48]. The U shaped submarine channels (Type 4 in particular), and its morphometry that lacked significant changes (Figures 5b,d, 8 and 9b,d), indicated that the extended and long process involving the movement of the fine-grained sediment to the submarine channels are without significant erosion [4; 19; 62]. Furthermore, the decrease in the top width of the channels in the eastern area (Figure 8a) is related to the contour current that shapes the sediment in a perpendicular direction to the direction of the channels. This is also supported by the presence of sediment waves in the flank area of the channels that represented contour current in the submarine environment (Types 1 and 4, see Figures 5a,d, 6a,d, and 9a,d). This current is known as a subtropical front with highly saline, nutrient-depleted, and warm surface water that flows in the S-N direction, perpendicular to the direction of the channels in the study area (northward-flowing southward current), along the New Zealand continental margin [35; 40; 41; 42; 63]. The lateral development of the channels' wall in the study area indicates the long processes of turbidity flows that occurred in the slope system of the submarine environment [2; 5; 6]. This is also supported by the relatively high channel top width value, compared with other morphometry elements (Figure 8). Furthermore, correlations between the increasing channel sinuosity and the widening channel floors inside the channel complexes have been observed in the study area (Figure 8e). This suggests a decrease in the dip angle of the submarine slope morphology with a relatively long history of channel development (Figure 9). This sinuosity behaviour is usually followed by channel cut-off in the later stages of channel development with channel complexes as an end product [5; 6; 12]. Furthermore, the provenance of the Cenozoic sediment in the Canterbury Basin was from the hinterland in the west (Figure 1a). It consists of volcanic, metamorphic (schist), and sedimentary rocks [32; 35; 36]. This relatively west to east sediment transport direction agrees with the late Cenozoic geodynamic evolution of the study area, where the Canterbury Basin that is located in the Eastern side of the New Zealand--South Island (sediment source area) was the depocenter in a submarine environment [44]. In addition, recent terrestrial rivers and their submarine counterparts display similar transport directions with Quaternary channels' complexes in the study area (Figure 10). This indicates less significant regional plate movement that could have deviated channel trajectory during the Quaternary in the study area (local processes might have occurred). Meanwhile, the northward-flowing southland current and the Antarctic Circumpolar Current contributed to the deposition of Pliocene--Pleistocene sediment drift in the study area [41; 42].