Journal of Creation 20(1), pgs 55-63, 2006.
JGL Comment: Some geologists had been attempting to construct a 6.5 million year deposition for the Green River Formation based on annual varve formation, but the above observations and other data argue against that view..
See links for comments and differing opinions as to whether the formation occurred during the Flood (M Oard) or Post-Flood (J. Whitmore). But both agree the sedimentation of the GRF did not take millions of years.