High-resolution photo geologic mapping of the Tuscan Formation cliffs in the BCCER and Upper Bidwell Park, Chico CA

The Tuscan Formation rocks make up the uppermost cliffs of the Big Chico Creek Ecological Reserve (BCCER) and Upper Bidwell Park. These rocks are composed of 3.2 to 1.8 million year old tuffs, conglomerate and sandstone dominated by volcanic clasts, as well as siltstone and mudstone mostly derived from the ancient Mt. Yana volcanic complex near Lake Almanor. This study attempts to investigate stratal geometries of Tuscan deposits in the BCCER and Upper Bidwell Park by mapping stratigraphic sections and using high resolution aerial geologic photomosaics of the Tuscan rocks. In order to obtain the best perspective of the rocks, the photos have been taken directly perpendicular to the cliff face using a helicopter and high resolution photography. With these photos, detailed layering and features of the Tuscan, both in the breccia units and the interbedded fluvial units, can be detected. These 'head on' photos are the best way to see erosional surfaces, pinch-outs, and individual flow units. They can also be used to document how well these features correlate down-canyon. Additionally, aerial photos provide a foundation for recognizing larger scale features and trends which would otherwise go unnoticed (channel flow direction, cross-cutting flows). One example of these larger scale features are two larger debris flows at the top of the unit that are best seen by the aerial photos. By foot, these debris flows can be difficult to access because of steep terrain and vegetation cover. These photos will not only aid in the study of the Tuscan deposits, but will potentially benefit other research focused on the hydrology, ecology, or archeology of Upper Bidwell Park and the BCCER. The Tuscan Formation. Debris Flow layers can easily be mapped from high-resolution photos