MAMMAL TRACKWAYS AND ASSOCIATED SEDIMENTARY STRUCTURES FROM PLIOCENE LACUSTRINE SEDIMENTS OF THE PALM SPRING FORMATION AT CAMEL RIDGE, ANZA-BORREGO STATE PARK, CALIFORNIA

A variety of diverse geological and biological features within Arroyo Seco del Diablo, Camel Ridge, Palm Spring Formation, Anza-Borrego Desert State Park provides a unique opportunity to study mammal trackways within a well preserved lacustrine depositional environment. Several tracks have previously been reported from Camel Ridge including: several types of bird tracks, camel tracks, and carnivore tracks. Sedimentary structures associated with these tracks include: a variety of ripple laminations, planar lamination, soft sediment deformation, and halite crystal casts. These are preserved in fine grained silt and mudstone sediments and also medium to coarse grained sandstone. The paleoenvironment is interpreted as a braided stream environment with intermittent flooding and sedimentation into a shallow freshwater lake. Mammal trackways are rare within the fossil record. This locality allows the unique opportunity to understand the facies relationships of these tracks within the context of the sedimentary environment for which they were formed.