Volcanic and Tectonic Processes and Crustal Construction at the Lucky Strike Segment — MAR 37°N: Field Collaboration with French scientists in TowCam and Nautile Investigations


DOEI Project Finded: 2006

I have been invited to participate on a French-funded cruise during August 2006 to collaborate with Valerie Ballu (Chief Scientist - U. Paris) and Javier Escartin (U. Paris, WHOI Adjunct in G&G Dept.) in near-bottom geological and geophysical studies of the axial valley of the Lucky Strike segment - Mid-Atlantic Ridge, 37°N. This collaboration is an extension of my successful work at the East Pacific Rise using Alvin and TowCam data [see relevant publications in CV] to develop quantitative mapping techniques and conduct analytical/modeling studies to deduce volcanic processes from high-resolution seafloor imagery, bathymetry, and geophysical data. My joint request to DOEI and Access to the Sea is to support my participation in this cruise and the related TowCam costs, which will help expand my research program, further establish collaborative studies at Lucky Strike with French colleagues, and will aid in observatory-type, time series studies at this important slow-spreading MOR field area.

The goals of this study are to investigate volcanic and tectonic processes within the rift valley of the LS segment relative to the recently imaged axial magma chamber beneath its segment center. Processes of crust construction in slow-spreading environments are currently debated, but with the recently imaged magma chamber and the proposed collection of near-bottom data, the opportunity exists at LS to make significant progress on this problem. Specifically, I seek to identify the areas of most recent volcanism and tectonism at several sites along the segment in order to determine whether crustal accretion is focused or diffuse and how it is influenced by proximity to the axial magma chamber. In addition, I seek to characterize the morphology and chemistry of volcanics as well as the spacing and throw of faults along- and across-axis, which may be similarly influenced by melt supply. The proposed data to be collected, along with existing sidescan sonar data, will be used to produce a detailed geologic map along and across the rift valley of the LS segment. This map will be used to address questions of crust construction within this MAR segment and to provide an observational baseline for numerous planned and future studies in this volcanically, tectonically, hydrothermally, and biologically active slow-spreading MOR segment.