The name “Mexican Hat” comes from a curiously sombrero-shaped, 60-foot wide by 12-foot thick, rock outcropping on the northeast edge of town. The “Hat”‘ has two rock climbing routes ascending it. It has frequently been noted on lists of unusual place names.
Steeply dipping strata define the western edge of the San Juan basin. To the west older geologic formations are exposed toward the Defiance uplift whereas basinward they are they are downwarped thousands of feet beneath younger rock units. Vast coal, uranium, oil and gas resources occur in the strata buried within the basin.
Elevation 5,050 feet.
Grove Karl Gilbert (1843-1918) is considered one of the greatest American geologists, having pioneered many theories in the earth sciences. In the late 1800s and early 1900s, Gilbert advanced concepts of mountain building, fault scarps, earthquake probabilities, and lake cycles that have withstood the test of time and are still used today. Furthermore, Gilbert applied science toward promoting public welfare by advocating the need for evaluation of risks and public disclosure of geologic hazards.
Utah was one of Gilbert’s favorite study areas where he formulated many of his theories. He spent much time at this particular location and was the first to establish that Little Cottonwood Canyon and Bells Canyon glaciers descended as far as the shoreline of ancient Lake Bonneville. Gilbert was also the first person to recognize the earthquake hazard posed by the Wasatch fault.
As you stand here look around, the magnificent cliffs, canyons, knobs, and spires before you are mostly cut from the 190 million-year-old Navajo Sandstone formation. Imagine the winds that carried sand to this area and deposited it in sand dunes hundreds of feet high. As wind shifted the massive sand dunes, the sands were deposited in a whirl of layers. Buried over eons of geologic time, the sands ceased their movement and turned to stone. Water releases the grains of sand from the grip of stone. Even here in an arid climate, water is the prime agent sculpting the stone into canyons, arches, and pinnacles. You are near the center of the great anticline that is the San Rafael Swell. Here, the layers are nearly flat-lying. It is like a stone dome with the curved top worn away. Soon the layers will begin tilting gently to the west.
(Located at the Ghost Rock Westbound View Area on I-70)
The Wetumpka Impact Crater is the only confirmed meteorite crater in Alabama, United States. It is located east of downtown Wetumpka in Elmore County, Alabama. The crater is 7.6 km in diameter and its age is estimated to be about 83 million years (Cretaceous) old based on fossils found in the youngest disturbed deposits, which belong to the Mooreville Chalk. The crater is well preserved, including the original impact rim and breccia, but exposures are few owing to plant and soil cover, and nearly all are on private land. Thornton L. Neathery discovered the Wetumpka Crater in 1969-70 during regional geological mapping and published the first article on the subject in 1976. However, conclusive evidence of impact origin was lacking until 1998 when David T. King, Jr. and colleagues discovered shocked quartz in a core drilled near the center of the structure. In 2002, Christian Koeberl with the Institute of Geochemistry University of Vienna published evidence and established the site as an internationally recognized impact crater.
Each year, the city of Wetumpka sponsors annual ‘crater tours’ for the public in cooperation with local landowners and authorities. In March 2007, the Geological Society of America sponsored an international field forum for impact geologists led by David T. King, Jr. and Jens Ormö.
In May of 2007, Auburn University graduate student Reuben Johnson earned his master’s degree studying the impact crater. This work added to a growing body of evidence that Wetumpka’s crystalline “rim” may instead mark the edge of a deep central basin within what was originally a much larger impact crater that has since been almost completely eroded away.
From here you have an excellent view of the Monitor and Merrimac Buttes to the northeast. These prominent land forms tower 600 feet above their Navajo sandstone base. They can be seen from many points as you travel along the highway.
The Monitor and Merrimac Buttes were named after the Civil War ironclad ships of the same names. If you look at a likeness of the old ships, their shapes bear a striking resemblance to these two buttes. The Merrimac (the large rock on your left) was the Confederate ship, called the “Virginia” by the southern forces. The Monitor (on the right) was the Union ship sent to destroy the Merrimac. The resulting sea battle changed maritime warfare forever. Long after both ships lie on the sea bottom, their rock counterparts remain locked in perpetual battle.
The Monitor and Merrimac Buttes are composed of Entrada sandstone. (This is the same rock layer that forms many of the arches in Arches National Park.) This Entrada sandstone is composed of three “members,” or components — Dewey Bridge, Slickrock and Moab Tongue. The different “members” of the Entrada layer erode at varying rates. Specifically, the softer Dewey Bridge member erodes more quickly, causing the Slickrock cliffs to collapse. This process has created the Monitor and Merrimac Buttes, as well as other towering monoliths in the area.
Geological forces have created the stunning landforms that we enjoy today.