Wylie Walker, Zane Richards Jobe, Leslie Wood, Rick Sarg

Sediment transport and partitioning are important for understanding slope-building processes in mixed carbonate-siliciclastic sediment routing
systems. The Permian-aged Bone Spring Formation, Delaware Basin, west Texas is a mixed carbonate-siliciclastic system that has been
extensively studied in its basinal extent, but poorly constrained at its proximal, upper slope segment. In this study, we constrain the
stratigraphic architecture of the proximal Bone Spring Fm. outcrops in Guadalupe Mountains National Park in order to delineate the dynamics of
carbonate and siliciclastic sediment delivery to the basin. These upper-slope deposits are composed predominantly of fine-grained carbonate
slope facies interbedded at various scales with terrigenous hemipelagic and sediment gravity flow deposits. We identify ten slope-building
clinothems that vary from siliciclastic-rich to carbonate-rich and are truncated by slope detachment surfaces that record large-scale masswasting
of the shelf margin. X-ray fluorescence (XRF) data indicates that slope detachment surfaces contain a higher-than-normal proportion of
terrigenous siliciclastic sediment, suggesting failure is triggered by accommodation or sediment supply changes at the shelf margin.
Furthermore, a well-exposed siliciclastic-rich clinothem, identified here as the 1st Bone Spring Sand, provides evidence that carbonate and
terrigenous sediment were deposited contemporaneously, suggesting both autogenic and allogenic processes influenced the Bone Spring Fm.
stratigraphy. This mixing of lithologies at multiple scales and the prevalence of mass-wasting act as a primary control on the stacking patterns
of siliciclastic and carbonate lithologies on not only the Bone Spring margin, but also in the distal portion of the Delaware Basin.