Yangtze river

China has probably the most widespread ongoing geologic activity in Asia. The downside of this is that they have had many devastating earthquakes that have killed thousand There are multiple areas in China where rivers cut through mountain systems instead of going around them. We will only concentrate on one river, the Yangtze, but will use two pictures. The picture above shows the Yangtze River and some of its tributaries in central China. The Yangtze enters from the lower edge and flows northeastward off the right portion of the top edge. Three major tributaries join at left the Fu, Jialing, and Qu and the combination joins the Yangtze.

Of interest are the ridges that are cut by these rivers. The ridges rise anywhere from to feet above the river systems. They look remarkably similar to the river ridge systems in the northeastern United States. See Ancestral Rivers of the Eastern United States. While very little is known about the uplifted history here in China, the similarity suggests that this also an example of superimposition.

The Wu enters from the right and is no slouch as it cuts across upturned sedimentary ridges to produce a foot deep canyon just inside the right edge. What will be of even more interest will be the Yangtze in the next picture when it cuts to the right, from the lowlands, back into these high ridges.Actual river elevations and the areas between the ridges typically run between and feet above sea level.

The horizontal extent of the picture spans about miles from the bottom edge to the top edge. Keep these dimensions in mind as you view the next picture. The picture above is another view of the Yangtze, but this is further downstream in the famous Yangtze Gorges. The Three Gorges Dam is about linear miles downstream and off the right edge. The Yangtze is cutting across ridge systems that range from feet above sea level. At the right cut, the mountain rises abruptly more than a mile above the river.