We have a new paper out in Earth and Planetary Science Letters led by former Sedimentary Systems Research group Ph.D. student and current post-doc Cody Mason.
Sediment supply has long been considered an important factor in observed depositional patterns and facies in sedimentary basins. Indeed, accommodation and supply are commonly invoked as the two fundamental controls on stratigraphy. However, directly measuring paleo-sediment supply from the stratigraphic record is a significant challenge. In most cases, sediment supply is estimated in a relative sense. Thus, the aim of this study was to calculate sediment supply, in an absolute sense, from outcropping Pleistocene alluvial and lacustrine deposits using cosmogenic radionuclides. We applied the catchment-integrated denudation (erosion) rate methodology that is typically used for modern river sediments to a succession of now-exhumed catchment-outlet deposits in Panamint Valley, California. This approach allowed us to generate a time series of paleo-erosion rates (which we use as a proxy for sediment supply).
The figure below (Fig. 6 from the paper) is a summary of our results. In order to calculate paleo-denudation rate we needed some constraint on depositional age, which we got using 10Be/26Al burial dating techniques. The ~180 m thick succession we studied ranges from ~1.2 Ma to ~0.3 Ma old (part D of the figure below). 
The resultant denudation rates (part E of figure above) show that the sediment supply out of the catchment varied from as low as ~24 mm/kyr to as high as ~54 mm/kyr with a long-term mean rate of ~36 mm/kyr. In the paper, we discuss the potential controls of glacial-interglacial climatic variability and Mid-Pleistocene Transition on source-to-sink dynamics. Additionally, we present an end-member mixing model to explore how sediment storage and/or landslide processes in the upper catchment may have influenced our paleoerosion rate calculations.
If you cannot access the EPSL version, you can get a freely available version on EarthArXiv (or feel free to email us and we can send you a copy).
Additional thanks to Ron Schott for joining us out in the field area during one our trips to take some beautiful GigaPan images of the outcrop (see the images called ‘Ballarat Delta’).