Learn more about Volcanos in Northern Arizona Guest post by Greg Zielinski Driving toward the Grand Canyon along Routes 180, 64, 89 and I40 from Flagstaff and other parts of Northern Arizona or when flying into the region, one can see many mountains and conical shaped hills, as in photo above. Almost all of these…
More About Grand Canyon’s Great Unconformity By Wayne Ranney, Grand Canyon Geologist In Part I of this posting, The Great Unconformity (TGU) in Grand Canyon was described as a long-lived gap in the rock record with a duration of about 1.2 billion years. It is positioned where the Tapeats Sandstone sits directly above the crystalline…
Grand Canyon’s Great Unconformity-Part 1 Written by Wayne Ranney, Grand Canyon Geologist and Author Whether you’ve taken one or seven Grand Canyon river trips or are preparing for your first, you might have heard of a geologic attraction called The Great Unconformity. It often seems as if this feature is more famous than the Canyon’s…
