Eocene Willwood Formation of the 2 Bighorn Basin , Wyoming , USA 3

13 Interaction of allogenic and autogenic forcing in building alluvial stratigraphy remains a complex 14 subject that is critical for paleoenvironmental and paleoclimate reconstruction and subsurface rock 15 property prediction. Astronomical forcing of alluvial stratigraphy is poorly documented so far as this 16 driver strongly interacts with autogenic and other allogenic processes making it difficult to trace 17 astronomical climate changes in these laterally highly variable sediments. In the lower Eocene Willwood 18 Formation, Bighorn Basin, Wyoming, USA, a lot of evidence has been gathered to relate dominant 19 floodplain aggradation cycles to precession-scale climate change. One floodplain aggradation cycle 20 consists of two phases: (1) a longer overbank phase with relative channel stability and strong paleosol 21