87Sr/86Sr Ratios in Carbonate From the Red Lake and Steep Rock Groups in Canada Suggest Rb-enriched Continental Crust was Influencing Seawater Chemistry Prior to 3.0 Ga

Aaron Satkoski1, Philip William Fralick2, Brian L Beard3 and Clark Johnson3, (1)University of Texas at Austin, Dept. of Geological Sciences, Jackson School of Geosciences, Austin, TX, United States, (2)Lakehead University, Department of Geology, Thunder Bay, ON, Canada, (3)University of Wisconsin-Madison, Department of Geoscience, Madison, WI, United States