There is a reason that most couples today do not have a significant age difference. Consider that over the last one hundred years, the average age difference between married couples is 3.5 years.
The Colorado River flows from the Continental Divide in Colorado's Rocky Mountain National Park into the Gulf of California between the Baja California peninsula and mainland Mexico. Here, Snowmass Mountain looms above the Roaring Fork River, a tributary of the Colorado. Peter McBride.
We know these rock layers were once connected, which is described in the rule of lateral continuity. Finally, the Colorado River cuts through all the layers of sedimentary rock to form the canyon. Based on the principle of cross-cutting relationships, the river must be younger than all of the rock layers that it cuts through.