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Tucson Oddity: What's with crater on edge of 'A' Mountain?

Tucson Oddity: What's with crater on edge of 'A' Mountain?

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"Midsummer Night's Dream" artwork decorates a pebble garden at George Mehl Foothills Park. The bronze shoes of people and fairies are "left behind" as visitors escape the real world for a little while.

Today's version of Tucson Oddity is a multiple-choice quiz.

Is that a crater on the Mission Road side of "A" Mountain?

(A) Yes - it's evidence of a volcanic explosion millions of years ago that killed the giant lizards and horned toads that once ruled this valley, leaving only those tiny lizards we see today.

(B) No - the huge pit was dug by University of Arizona students to trap the commando squads of Arizona State University Sun Devils that yearly tried to paint the "A" on the mountain gold and maroon.

(C) "A" Mountain is not a volcano but was formed by volcanic flows when the area's larger mountain ranges exploded into being 10 million to 20 million years ago.

The cooled lava, or basalt, at "A" Mountain's base was mined to supply foundations and rock walls for many UA-area buildings in the early decades of the last century, said Gayle Hartmann, archaeologist and Tucson history buff.

Archaeologist Homer Thiel said there were two quarries. He wrote this account for the Menlo Park Neighborhood newsletter:

"A large stone quarry operated on the north slope of Sentinel Peak from the late 19th century into the 1930s. A volcanic vesicular basalt, called 'malapai' in the archival Building Record Cards, was used in the Tucson area for foundations, fences and porch pillars. In a few cases, entire structures were made from the rock, including several homes in the Menlo Park neighborhood. The quarry eventually closed after the city of Tucson acquired Sentinel Peak as a city park."

Correct answer: Oh, c'mon. You can figure it out.

Got an oddity?

Is there something you've noticed while driving through Tucson that has piqued your curiosity to the point that you wish you could find out more about it? Drop us a line, and we'll look into it. Call the Star newsroom at 573-4142 or send an e-mail to

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