Geologic road logs are some of the most useful tools
field geologists and rockhounds have at their disposal. These logs describe geologic features and stratigraphy,
at specific mileages, that are visible along the road in question. In the pre-electronic age most road logs were
printed in guidebooks published by various geological societies (and these
remain a wealth of information so check at your local academic library). I have found these roads listed below useful and
interesting as I make annual visits to the Tucson "show."
Rockhounds take note: as usual, be careful, take the
necessary precautions when traveling, do not trespass on private land, and know
the local collecting regulations.
COLORADO PLATEAU TO GREAT BASIN http://www.aipg.org/2008/Phoenix%20to%20Flagstaff%20Road%20log.pdf
The road log describes the geology from Flagstaff,
located in the pine trees of the Colorado Plateau, down elevation through the
Transition Zone, and into the Sonoran Desert of the Basin and Range.
KAYENTA TO MEXICAN WATER, ARIZONA: http://www.fourcornerssw.com/kayenta_to_mexican_water__ariz.html
Monument Valley in the northern part of Arizona
occupies a prominent place on many travelers’ bucket list. The road logs follow Jurassic and Cretaceous
rocks exposed on the mesas and in the drainages. The bonus exposures include the numerous
igneous rocks called diatremes.
THE APACHE TRAIL: http://repository.azgs.az.gov/uri_gin/azgs/dlio/1007
Readers will need to locate this web site then click
on the hot link Guidebook 4-Highways of
Arizona. Although this log is about
40 years old, it gives a nice tour of the Apache Trail from the city of Apache
Junction north by the Superstition and Goldfield Mountains to the campground
and marina at Canyon Lake.