Paper has good bibliog, Experiments are on Pierre bentonites only. Good survey giving general aspects of bentonite. Heyes, John. R. 1950 PhD thesis U of Colo 378.788 A, H 3273 C. Cretaceous stratigraphy of eastern colorado Good paper. Analyzes subsurface Dakota - along with Goldsteins work this is a must reference before writing it up. Chief contribution is evidence of northward intertonguing of Benton + Dakota. Also that sharp Morrison contact in many electro logs, - check see how SS porous vs SS with fines reacts - may be key to it. Some ref: Lovingston, C.S. Greenwood oil field Weld Co. Colo. Estratig. type oil fields. - AAPG 1941, ppi 14-43 (on this Greewwood tongue.) Reutkin C.H, Jr. - AAPG vol 17, no 4 1933 - well sections in NE. Colo. 58.