Professor Jim Wright and four graduate students sailed on a research cruise aboard the RV Thomas Thompson, leaving from Montevideo, Uruguay on September 11th and returning on October 31st. Aaron Watters (Ph.D.), Mark Yu (Ph.D.), Tim Shamus (M.S.), and alumnus Alex Adams (MS, 2019) joined researchers and students from Texas A&M and the College of Charleston to explore the southern Argentine margin. On this 51-day cruise, the research team collected high-resolution seismic lines, multibeam bathymetry data, and a suite of cores from the southern Argentine margin. Over 4000 km (2135 nM) of high-resolution seismic data allowed the team to see the margin’s geologic architecture. One of the aims of the investigation was to image locations where sediments and deep ocean currents interact, forming large sediment drifts. Sediments are swept to the deepest parts of the continental margin (>4000 m) through a series of canyons where strong bottom water currents have sculpted the sediments producing sedimentary deposits over 2 km thick over the past 14 million years. A second sediment drift is developing in water depths between 2200 and 2800 m and appears to be a younger drift deposit. The research team also collected sixty-two cores from water depths spanning 750 to 4500 m, recovering >380 m of sediments. Eighteen jumbo piston cores (up to 14 m) recovered sediments that encompass the most recent glacial to interglacial cycles. Older sediments exposed on the margin were also recovered using a gravity core within a 20 ft steel core barrel known as Big Bertha. Shore-based biostratigraphic analysis will be conducted on these sediments. The research team will work on the data and cores collected over the next 4 to 5 years and will support a variety of graduate and undergraduate research projects.
