Hells Canyon is a huge gorge that runs along the border of Idaho with Oregon. A new study indicates a monumental shift in the Snake river drainage system reshaped the topography – carving out the canyon which plunges a surprising 2,400 m. It is deeper than the Grand Canyon, we are told. A remarkable narrow valley formation in the mountains – see https://phys.org/news/2025-06-cave-deepest-river-gorge-hells.html … It adds, this occurred 2 million years ago, a date derived from cosmogenic nuclides. High energy particles from space, known as cosmic rays to most people, constantly bombard the Earth. When they strike rocks, or sediments, they can interact with radioactive isotopes. These are cosmogenic nuclides. They accumulate over time in the uppermost layers of rock or sediment. Canyons, on the other hand, are relics of tectonic activity. They also reflect sharp changes in climate, they also add. However, the geological consensus is that canyons and river valleys, in general, are formed by water. In this case, the Snake river. Canyons also allow aquatic species to migrate through mountainous regions, so water is definitely the major player. The article says that geologists are not entirely sure on the processes involved to form these steep ruts in the rock. Catastrophism is of course not broached. Hence, opinion musters around a change in the flow of rivers as primarily responsible. Uniformitarian thinking is provided with some 2 million years in which to carve out the canyon, and this is arrived at by sediment analysis in a cave above the present water line of the Snake river. The water flow must have been much more dramatic in the past to strand the cave above the river – although this is compensated by reason the erosion of rock means the river descended downwards leaving the cave some way above it. The study defines the episode as occurring between the Late Pliocene and the early Pleistocene. Conveniently located on a geological boundary. these are often associated with catastrophic changes in climate. The sediment cores provided the cosmogenic nuclides to arrive at a date of 2 million years in the past.
At https://wiki.aapg.org/Super_basins … is a nice essay on the geology of river basins. They play a role in the geological search for oil and natural gas. They are also often asssociated with rifts, passive margins, and intracratonic tectonics. Most of them go back to the Jurassic or Cretaceous periods – but not all of them. They are often associated with oil deposits and are a matter of interest to oil exploration geologists. Super basins include the Permian and the Gulf of Mexico, and in Europe, the North Sea basin. Excellent read.