47+ Geologic History Of North America Timeline Images. Spreading, which originates at oceanic ridges, is. Mountain chain along w side of n.
(ma = millions of years ago).
University of california's museum of paleontology has created a hyperlinked geologic timeline with all sorts of details about each time unit that may be useful later in the course. University of california's museum of paleontology has created a hyperlinked geologic timeline with all sorts of details about each time unit that may be useful later in the course. While parts of the craton peek out in greenland and canada, in the u.s., thick layers of sedimentary rocks keep most of these ancient. Some descriptive information about the different divisions of geologic time is given below.
