Uniformitarian principles would dictate the level of sedimentation to be far greater that what is observed where the Mississippi river feeds into the Gulf of Mexico. Near the mouth of a muddy river flowing into the ocean, it is common knowledge that sediments transported by the river slowly settle out of the water and form deposits on the sea floor. In some locations, such as the delta regions near the mouth of the Mississippi River or the Nile River, the build-up of sediments has resulted in the addition of large regions of new land. Observed and measured sedimentation can be used to estimate the river to being thousands of years old and not hundreds of thousands of years old.
http://www.icr.org/research/index/researchp_lv_r01/
