Research

Sediments and sedimentary rocks record Earth surface processes through time and can be analyzed to reconstruct environments and their relationship to climate, oceanic circulation, sea-level change, tectonics, and source-to-sink dynamics. Our group analyzes ancient and modern/recent sedimentary systems with an emphasis on deep-marine sedimentation. 

Paleoceanographic Sedimentology

We use the fundamentals of sedimentology (grain-size analysis, seismic stratigraphy, etc.) to reconstruct past oceanographic processes of regional to global importance. 

  • Response of North Atlantic Ocean Circulation to Global Change at the Eocene-Oligocene Transition (EOT) 
    • Brian Romans sailed on IODP Exp 342 in 2012, which recovered Eocene-recent deep-sea contourite records from the Newfoundland ridges
    • Ph.D. student Drew Parent (Ph.D., 2022) generated a terrigenous grain-size data set (integrated with data that former student Kristin Chilton (M.S., 2016) generated for her M.S. thesis in 2016) to investigate bottom-current response to global cooling at the EOT.  
    • Published studies from former students and collaborators:
  • History of Antarctic Bottom Water (AABW) Production in Response to Pliocene-Pleistocene Climate Variability
    • Brian Romans sailed on IODP Exp 374 in 2018, which is focused on reconstructing West Antarctic Ice Sheet and Southern Ocean response to climate variability in the Miocene through recent with Ross Sea sediment cores.
    • Ph.D. student Natalia Varela (Ph.D., 2024) investigated the occurrence, frequency, and characteristics of thin-bedded turbidite deposits from the levee of Hillary Canyon on the Ross Sea continental slope and rise as a proxy for AABW outflow. Natalia presented preliminary results of this research in a poster at AGU in 2019. 
  • Experimental Test of the ‘Sortable Silt’ Proxy
    • Brian Romans and Kyle Strom (Virginia Tech Dept. of Civil & Environmental Engineering) were awarded a ‘New Directions’ grant from the American Chemical Society (2017-2020) to experimentally test the widely used paleoceanographic proxy referred to as ‘sortable silt’. 
    • The first of two papers summarizing this research was published in Sedimentology in 2021. Stay tuned for a follow-up paper. 

Sedimentary Systems from Source-to-Sink

The linkage of erosional catchments (sediment source areas) to depositional basins provides insights into system-scale dynamics and reconstruction of climatic and/or tectonic signals in the stratigraphic record.

  • Ph.D. student Drew Parent (Ph.D., 2022) reconstructed Early Cretaceous (~145-125 Ma) sedimentary landscapes of the U.S. Atlantic continental margin using detrital zircon U-Pb ages from fluvial and submarine fan deposits are being used to test hypotheses about paleo-drainage configuration, tectonic controls, and sedimentary system scaling. Watch Drew’s recorded talk for GSA 2020 meeting here.
  • Former Ph.D. student Neal Auchter (Ph.D., 2016) led a project that used strontium isotope stratigraphy on re-sedimented marine fossils to constrain occurrence and timescales of intrabasinal sediment recycling. This work, which was based on a chapter of Neal’s dissertation, was published in Geology in 2020 (see this blog post summarizing the study).
  • Post-doctoral fellow Cody Mason (Ph.D., 2017; Post-doc, 2018) led a study to examine controls on source-to-sink dynamics of the largest drainage system in the world, the Amazon River and submarine fan, using detrital zircon geochronology. We found that sediment transfer is governed by sea-level-controlled base level coupled with hydroclimate variability over Pleistocene glacial-interglacial timescales. This work was published in Geology in 2019.  
  • Ph.D. student Cody Mason (Ph.D., 2017; Post-doc, 2018) led a project to quantify paleo-erosion rates from a Pleistocene catchment-fan system in Panamint Valley, California, using cosmogenic radionuclides (10Be and 26Al). We integrated paleo-erosion rates with interpretations of outcropping sedimentology and stratigraphic architecture to show that higher sediment supply occurred in association with transitions into/out of climatic (pluvial lake) phases. This work was published in Earth & Planetary Science Letters in 2018 (see this blog post summarizing the study).
  • Brian Romans and collaborators published a review paper about signal propagation in sedimentary systems across multiple timescales in Earth-Science Reviews in 2016. This paper provides a comprehensive review of seminal studies and ’state of the art’ concepts and tools for those interested in the linkage of erosional and depositional segments of sediment routing systems. See Tofelde et al. (2021) for a follow-up paper on the topic of signal propagation.

Stratigraphic Architecture and Evolution of Deep-Water Slope Systems

Outcrops of ancient depositional systems reveal the complexity of stratigraphy at a large range of scales and is valuable for linking processes to larger-scale stacking patterns. Outcrop studies can also be used to improve characterization and prediction of analogous systems in the subsurface.

The Chile Slope Systems consortium, established in 2012, is a multi-institution and multi-disciplinary research program funded by petroleum companies that is conducting fundamental research of deep-marine slope (turbidite) systems. Spectacular outcrops of the Cretaceous Magallanes foreland basin in southern Chile are a primary focus.

  • M.S. student Michala Puckett (2022-2024) is using quantitative textural information (grain size and sorting from petrographic analysis and measurement) to investigate variability in the context of slope channel-fill architecture.
  • Recently completed Ph.D. student Sebastian Kaempfe (Ph.D., 2022) researched several aspects of the Magallanes Basin deep-marine stratigraphy:
    • Sedimentology and architectural relationships of submarine channel-fill and associated internal levee deposits. Sebastian presented preliminary results of this research at AAPG 2018. (This paper has been accepted for publication in Sedimentology.)
    • Role of syn-sedimentary faulting and clastic injection at a major transition in foreland basin evolution. Sebastian presented preliminary results of this research at AAPG 2019.
    • Timing and regional paleogeography of along-strike sediment input to a deep-marine foredeep. 
  • Published studies from the Chile Slope Systems team, including former students of Sedimentary Systems Research group: