Post by
dragonfly454 on Nov 25, 2021 12:07pm
Slope
Within the study area, the Berbice Canyon incises into a substrate that has an average gradient of roughly 1.7 degrees. This value exceeds the typical gradient of a passive margin shelf, which is ~0.1degrees as observed on the current Guyana margin. Therefore, it is possible that the Berbice Canyon may have formed on a steeper than normal shelf or incised the shelf only near its shelf break and is predominantly situated on the slope. However, there is evidence to suggest the potentially greater likelihood of the former. Regional structural and free-air gravity maps of the Guyana-Suriname basin suggest evidence of a shelf-located depocenter in the Cretaceous that roughly coincides with the study area location (Figure 6.1). This Cretaceous depocenter is located on a structural low observed in the Jurassic acoustic basement, suggesting that the Cretaceous depocenter is above a Jurassic Graben (Yang & Escalona, 2011). A structural high can be observed in the proximal region(Kawa zone) of the study area that is truncated by the Albian Unconformity (Figure 4.4). There is also evidence of significant normal faulting. The study of the basement structure was out of the scope of this study, but could be explored in the future to dispute or confirm the notion of a steeper shelf caused by underlying structure....Me thinks it's the underlying structure