LUNETTES OF THE SAN LUIS LAKE RECREATIONAL AREA AND GREAT SAND DUNES, COLORADO

The Great Sand Dunes and San Luis Lake Recreational Area is located within an embayment complex along the western side of the Sangre de Cristo Mountains, at a point where the range shifts from southeastern trending to south-southwestern trending. The aeolian sand sheets and dunes of the region of study, cover an area from the Dry Lakes in the south to Deadman Creek in the north. Within these sand sheets and aeolian deposits are well defined lunettes associated with recent and historic playa lake systems. While the largest of these lunettes is adjacent to the San Luis Lake Recreational Area, and therefore bears the marks of anthropological intervention concerning water levels in the lake, the remaining lunettes have been left in their natural state. These lunettes are of great interest pertaining to the paleoclimatic history and trends of the San Luis Valley in the lands surrounding the Great Sand Dunes. Recent work has shown that these lunettes appear to have a different internal structuring than that of typical lunettes, which may be tied to the climatic history of the region.