The Great Desert


Next       Back

Focused images of the Meteor Crater and its Geology.

West Wing
Overturned Flap

West facing wall of the Meteor crater. The upper slopes, in tan cliffs, are of Kaibab limestone, same as we saw at the Grand Canyon. The lower slopes, whiter, are in Coconino sandstone. If you follow the prominent brown layer away across the wall, you'll see it jumps up in the middle of the image. This is a fault, a tear fault, produced in the asteroid impact that made the crater. The lower slopes are made of loose rock, talus, weathered from the upper crater walls. Brighter streaks on these slopes are debris flows -- water-laden flows of rock and soil. These debris flows are comparable, in some ways, to the gullies seen on the walls of Martian impact craters.
Geologic details on the west-facing wall of Meteor Crater. [1] Overturned flap. The explosive force of an asteroid impact bends the rock up and out from the impact site, overturning it at the crater rim. The red line here follows a single rock layer within the Kaibab limestone (tan-reddish). The layer bends over and, at the rim, lies on top of younger beds in the Kaibab! [2] Impact ejecta The loose boulders at the rim, like at the far left, were ejected from the crater and then fell back higgledy-piggledy onto the ground. [3] Notice that the rock on the crater's walls is broken and shattered. Not at all like the rock we saw in Grand Canyon.
Mine workings
Topographic Rim

Remains of rock drills and tunnelling equipment at the crater floor - remnants of the futile search for the iron asteroid that made the Meteor Crater. Now, it is generally accepted that the force and heat of the asteroid's impact vaporized it. The white rock near the drill holes is tufa - limestone deposited in a fresh-water lake. During the glacial eras, the climate on the Colorado Plateau was much cooler and wetter than it is now, and groundwater probably flowed into Meteor Crater (through its broken wall rocks) to form a lake. The tufa has impressions of leaves and stems in it.
Pieces of iron meteorite are (were) found all around meteor crater, and are probably fragments of the asteroid that made the crater. The one on the pedestal here is among the largest meteorites - the largest weighs more than 1400 lb! These meteorites are named "Canyon Diablo", after the arroyo that runs near the Meteor Crater.

Next - Meteor Crater 3  |  Back - Meteor Crater 1  |  Back to Workshop Index
Back to "The Great Desert"
LPI home page | LPI Education Resources Page
Copyright Allan Treiman, LPI.
Updated 09/06/03.
Comments to