| Description |
Methods of geoarchaeology, geochemistry, and geophysics are used to reconstruct the hydrologic system of the Sevier basin and Old River Bed inland delta of central Utah, as well as its usage by human foragers during the Pleistocene-Holocene transition. This is accomplished using kernel density estimation to reconstruct forager land-use, the measurement of 87Sr/86Sr ratios of mollusks from dated channels of the Old River Bed inland delta, and ground-penetrating radar of a barrier spit in the Sevier basin. Results show that foragers at the Old River Bed inland delta preferentially used the terminal ends of channel systems where standing water would have been capable of sustaining wetlands. 87Sr/86Sr ratio analysis of mollusks from several of these channel systems show that the predominant source of water to the region was from the Sevier basin via lake overflow during the Late Pleistocene and groundwater flow during the early Holocene. Ground-penetrating radar was used to image the Bitterweed Spit of the freshwater lake in the Sevier basin known as Lake Gunnison. Radar reflections show sigmoidal-oblique structures associated with sediment deposition in a stable overflowing body of water and support the 87Sr/86Sr ratios of mollusks at the Old River Bed inland delta that are consistent with lake overflow providing water to the region during the Late Pleistocene. |
