Dinosaur Mountain

Dinosaur Mountain is more a ridge or an elongate hill than a mountain.

It is located slightly east of the geometric center of Gold Canyon so it divides the community into two natural parts. It gets its name from its appearance which is similar to the back of the stegosaurus dinosaur.

Dinosaur Mountain is formed by intrusions of rhyolite and dacite magmas which rose toward the surface along fractures and cooled and congealed in the fractures to form dikes. Rhyolite and dacite are both high-silica, fine grained igneous rocks, but rhyolite contains a higher amount of silica than dacite. These intrusions are associated with the volcanism that formed the Superstition Mountains which are located about 4 miles north of this site.

On the geologic map* below I have hand-colored the above geologic map* to make the geology easier to visualize, although the coloring makes it more difficult to read some of the individual symbols. The location of my home is indicated on this colored map with a red "+" sign. It is in the gray-colored "Tdc" rock unit: dacite which was dated at 29 million years where it is also exposed near Hieroglyphic Canyon.

* The geologic maps are from the Arizona Geological Survey Open File Report 95-9 by Skotnicki and Ferguson.

Someone, perhaps a local golf course, has placed some old mining equipment high on the ridge at the southern end of Dinosaur Mountain in a promiment location to be seen from King's Ranch Road. This may imply to passers-by that there may be valuable mineral deposits there. Unfortunately, there isn't anything valuable or unique about the rhyolites and dacites of which the ridge is composed. However, as far as I know, nearby on the eastern slope of the ridge is the only area within the boundaries of Gold Canyon that are conspicuously posted with a "No Trespassing" sign, which limits the ability to more fully explore the Dinosaur Mountain landform.

For the latest geologic map and associated report on Gold Canyon and the nearby Superstition Mountain, see the following: http://repository.azgs.az.gov/uri_gin/azgs/dlio/246

Rhyolite and dacite are common igneous rocks in this area. Here are links that give more detail about these similar rocks: https://flexiblelearning.auckland.ac.nz/rocks_minerals/rocks/rhyolite.html and https://flexiblelearning.auckland.ac.nz/rocks_minerals/rocks/dacite.html

For additional information about the commmuity of Gold Canyon, see the following website: https://goldcanyon.net