An integrated field mapping - laboratory- hydrologic modeling study will be conducted for the "Kicking Horse Rim" of the southern Rocky Mountains in Canada, a well-exposed belt of massive replacement dolostone approximately 10 to 15 km wide that demarcates the transition from shelf to basin along the Lower Paleozoic passive margin of western North America. Preliminary field work strongly suggests that the replacement dolomite is related to a complex network of large (hundreds of meter-scale), dolomite breccia-and cement-filled fractures and pipes that riddles the area. Research will entail: (1) mapping the locations of the dolomite fractures and pipes through the massive dolomite of the "Kicking Horse Rim"; (2) documenting the transitions from these dolomitization centers into the fine-grained replacement dolomite and ultimately into the host country rock; (3) analyzing the fluid inclusion, isotopic and trace element geochemistry of the various dolomites; and (4) using data from (1), (2), and (3) as modeling constraints in numerical simulations of various hydrologic systems that could be responsible for dolomitization. This study offers an integrated field-laboratory -modeling approach toward dolomitization by examining a dolomite body similar in scale to many other massive replacement dolomites found in carbonate platform deposits. The Kicking Horse Rim dolomites are important insofar as warm, near sea water salinity fluids may have been important during dolomitization. The approach outlined here should be applicable to the problem of the origin of dolomites in general. Finally, the exact nature of the Kicking Horse Rim dolomite may have important implications for the argument as to the geometry of the shelf to basin transition.
