Search

Three and possibly four Molcelumne River fan deposits and gravel-filled channels interfinger deltaic sediments in the central part of the Great Valley of California. The channels were probably cut during successive glaciations in the Sierra Nevada Mountains, and graded to eustatically lowered and possibly subsiding base levels. Rising seas caused thalassostatic sedimentation and headward expansion of the California Delta during interglacial time. Radiocarbon dating of basal deltaic peat indicates the Pleistocene-Holocene transition occurred about 10,700 years ago in this part of California. [ABSTRACT FROM AUTHOR]