About 237 million years ago theMoenkopi Formation rocks were deposited in a coastal plain that covered what is now northern Arizona and surrounding states. The plain ended at the shoreline of a sea in Utah. Seasonal stream beds crossing that plain deposited thick sheets of sand. Over millions of years, “another 10,000 feet of Mesozoic sedimentary rocks accumulated.”
All of these sedimentary layers have been warped, twisted and eroded, ending up being uplifted by molten lava between 70 million and 30 million years ago as a huge chunk of thick crust. This was the origin of the Colorado Plateau, a 130000 square-mile block. In time, that molten base began to erupt in the San Francisco volcanic field, creating thousands of cinder cones, long lava flows, the stratovolcano known as San Francisco Mountain, and lava domes like Mount Elden near present day Flagstaff. Volcanic activity continued, with the most recent eruption occurring in AD 1064. At that time, the Sinaguan people found that the loose cinders made a good mulch for growing crops, and they created Wupatki. They used the red Moenkopi sandstone exposed in the area along with Kaibab limestone and black basalt from the volcanic field to build substantial buildings.
Centuries later, when the railroads necessitated the creation of the town of Flagstaff, the buildings were made of wood. However, over the years the citizens learned the same lesson that many cities of the day learned, as fires consumed the town. When reconstructed, the materials of choice were identical to those of the ancients, Moenkopi sandstone, Kaibab Formation limestone and volcanic basalt.
Used copies of the Stone Landmarks are available for purchase at various booksellers. Photos are my own.
What a great idea, and something I didn’t know about, despite a life-time of living in Arizona. Thanks.
If you haven’t yet made a trip to the Arizona Capitol Museum, you should — and soon. First, it’s free. Second, the museum specializes in teaching Arizona government and civics, using, per their website, “a balance of technology, hands-on activities, historical artifacts and public programs to help visitors learn about and interact with the government of the 48th state.” Third, a new exhibit at the museum, “Arizona Takes Shape,” will show visitors just how Arizona came to be, and it includes a cool interactive component called “History at Your Fingertips.”
Below, Jason Czerwinski, the museum’s on-site experience manager, talks about this exhibit:
Talk to us about “History at Your Fingertips.” What is it exactly, and what can visitors expect?
“History at Your Fingertips” is actually a smaller component (or an exhibit within an exhibit, if you will) of the Arizona Capitol Museum’s newest exhibit, “Arizona…
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Interior photos and information here.
Construction on the current San Xavier del Bac began in 1783. More than 200 hundred years of harsh desert climate, use, abandonment and attempts at restorations have taken a toll on the interior and exterior of this incredible structure. Finding funding for proper conservation has been an ongoing challenge.This year, 2014, conservation and preservation efforts are underway. Photos here.
San Xavier del Bac: The White Dove of the Desert