In geology, one operates from the premise that in almost all cases, the bottom layer of rock was deposited first (in much the same way you make lasagna). In these two diagrams, the geologic history would have been that the lower folded or tilted layers were deposited first as sedimentary beds, then the layers were uplifted and folded, then a period of erosion rather than deposition occured (creating the broken line which cuts through the folded layers, then the area subsided and deposition began again, creating the horizontal layers on top. Unconformities represent a period of erosion.
In Central Indiana and Ohio, because the glaciers came through here, the earlier deposited layers of Pennsylvanian, Missippian, and Ordovician rock are not present, although they are in the hilly southern parts of our states where the glaciers did not reach.
The presence of an unconformity in the Grand Canyon is actually a rather common geologic occurence, since it is very unusual to find a place with an unbroken history of deposition with no erosion. The writer cites the lack of deposition for a geologic time period as proof that evolution didn't happen, if I am reading this correctly. That is not true. It doeosn't prove that evolution DID happen either. It simply is a place with some missing rock record.
Prior to the Ice Age, the rocks in Indiana indicated that at one time Indianapolis sat under an inland sea. Those rocks were carried to the south by the glaciers, and deposited in moraines south of my house. The rock record in southern Indiana still shows the evidence. Just because the evidence has been removed from where I sit typing this does not mean that for 2 billion years Indiana was a fertile glacial plain.
I hope I am explaining this correctly.
More on neo-catastrophists later...the author is misinterpreting their position.