Quantitative analysis of the morphology and topography of subaqueous mass transport deposits, and their effect on healing-phase deepwater gravity flows overlying the mass transport deposits

Abstract

This research compiles three research projects investigating subaqueous landslides and their resultant deposits (also known as mass transport deposits [MTD]) and the influence of these deposits on post-MTD deep-water turbidite systems. It is now widely understood that these deposits constitute a major portion (upwards of 50%) of many deep-water systems worldwide. However, morphology and topography of MTDs and the influence of MTDs’ surface topography on subsequent sediment gravity flow deposits are still understudied and yet to be quantified . In addition, the geometric scaling relationships in MTDs are in need to be quantified for predicting the areal extent and surface characteristics of MTDs. This dissertation provides an overview of objectives and brief summaries of key findings in the introductory chapter, Chapter 1. This dissertation addresses this gap by quantitatively analyzing how the MTD’s surface topography affects the distribution of overlying turbidites in offshore Trinidad in Chapter 2. Chapter 3 addresses the geometric scaling relationships of morphological and topographic expressions of subaqueous landslides in the northern Gulf of Mexico and southern California to improve the ability of predicting MTD morphology and topography. Some of these scaling relationships can be used to predicting the nature of post-MTD deep-water deposits as well. In addition, Chapter 4 employs stratigraphic forward modeling to investigate how topography affects the distribution and stratigraphic architecture of deep-water deposits and compares the findings to understand the nature of deep-water deposits overlying MTDs.