Mudstones are fine-grained sediments that are very abundant throughout earth history. Their minerals record the state of ancient weathering, past climates, and changes in ocean chemistry. Because of their fine-grained nature they also are very effective to seal in and preserve organic components, such as plant and animal fossils. As such, mudstones contain the lion's share of information available to us on recorded earth history. Despite of that significance, however, our understanding of the processes that deposited the mudstones of the past is rudimentary. Thus, understanding these processes and identifying them in the rock record has to be an essential aspect of our attempts to read out of the rock record the conditions of the past, such as climate, atmosphere and ocean chemistry, and effectiveness of recycling of biologically important chemical elements (e.g. carbon, sulfur, phosphorous). PIs will begin to fill this gap in our understanding through a series of flume experiments where they subject mud substrates to a range of influences in a laboratory flow channel. With the proposed flume facility PIs plan to quantitatively explore the factors that influence mudstone deposition, and the small-scale sedimentary features that result from combinations of a variety of parameters. These parameters include for example salinity, clay type, flow velocity, water content of mud, continuous vs. episodic sediment supply, and wave action. The data collected in this study will provide a baseline for interpreting the physical aspects of mudstone deposition, and will also allow them to identify priority areas for future research.
