PhD Feng Ding

The general scientific goal guiding the PhD study is to understand cold fluid seeps from various geological perspectives. Geological processes are heavily involved in occurrence of seeps. Virtually all aspects ranging from sedimentation history (and resultant lithological column), sediment deformation history, sediment physical and chemical properties, sediment structures, geothermal history all can influence the occurrence and nature of seepage. Strictly speaking, all these aspects would be understood to predict the seeps’ occurrence, characterize their natures, and reconstruct their evolution. In the end, only seepage is understood as a geological phenomenon and over geological time scale, their contributions on global climate changes, marine environments and marine water chemical inventories can be better estimated.

Under this general guide line and for the complexity of a PhD study, we suggest focusing on the study of near-surface (1 – 2 km below seafloor) sediments and structure features under targeted seepage sites, to reveal the casual link between geological processes in upper of sediment column and fluid seepage. More specifically, the approach first aims for better understanding of sedimentation and tectonic history of the near-surface sediments, and the resultant subsurface structures. It is also complemented by analyses of fluid-indicating seismic features: bright spots, blanking zones, BSRs etc. By applying these results, the ultimate goal is to discuss for their controls on migration, focusing, accumulation of cold fluids, as well as the occurrence and evolution of fluid seepage. Such a study would also more directly assist other studies of Marum Project “Seepage of fluid and gas”, which focus on characterizing basin surface or extremely shallow depth of seep sites.

Cold seep areas, predominately clustered around continental margins, occur in a great variety of sedimentation and tectonic regimes in global scale. In order to cover a reasonable range of tectonic and sedimentological process for discussion, two study areas are chosen for the study, which have distinctively different tectonic settings. They are namely Campeche Knolls, southern Gulf of Mexico, a passive margin under active salt tectonism, and Makran accretionary prism, a convergent margin with thickest converging sediments in the world. The selection of the two study areas enables us not only to study individual areas, but also to compare them for a general discussion of the relationship between shallow geological proecesses and cold seepage.

To serve this study goal, proper datasets that can reveal near-surface features of seepage area and further hint into the geological processes behind these features are required. For the two deep water study areas, we chose high resolution multichannel seismic as the prime dataset, because it can both provide detailed subsurface acoustic information and allow moderate penetration. In principle, high frequency echosounder (e.g., Parasound) and swatch bathymetry data can be supplementary for the study. Although using predominantly seismic and acoustic data, the research goal prescribes that our research approach is different from those using acoustic features to directly identify and map the distribution of seepage. In addition, because the study approach emphasizes on geological processes and general structural patterns, it does not always require seismic and acoustic data with ultra-high spatial density. Thus, it can fully utilize sparsely spaced 2D seismic data in our study areas (in addition to high density seismic grids at several sites), which are collected in limited acquisition time.

Attend Major Cruises

Publications

• Feng Ding and Zhongli Ding, 2003, Chemical weathering history of the Southern Tajikistan loess and paleoclimate implications. Science in China (series D), 46(10), 1012-1021
• Shiling Yang, Feng Ding and Zhongli Ding, 2006, Pleistocene chemical weathering history of Asian arid and semi-arid regions recorded in loess deposits of China and Tajikistan. Geochimica et Cosmochimica Acta, 70, 1695-1709
• Feng Ding, Volkhard Spiess, Markus Brüning, Noemi Fekete, Hanno Keil and Gerhard Bohrmann, 2008, A conceptual model for hydrocarbon accumulation and seepage processes around Chapopote asphalt site, southern Gulf of Mexico: from high resolution seismic point of view. Journal of Geophysical Research, 113, B08404

First Author Manuscripts, Submitted

• Feng Ding, Volkhard Spiess, Ian R. MacDonald, Markus Brüning, Noemi Fekete, and Gerhard Bohrmann.Shallow sediment deformation styles in north-western Campeche Knolls, Gulf of Mexico and their controls on the occurrence of hydrocarbon seepage. Submitted
• Feng Ding, Volkhard Spiess, Bramley Murton, Noemi Fekete, Markus Brüning Gerhard Bohrmann. Interaction between accretionary thrust faulting and slope sedimentation at the frontal Makran accretionary prism and its implications for hydrocarbon fluid seepage. Submitted