Entries by Lance Weaver

The Cockscomb Monocline & Cottonwood Wash of Grand Staircase Escalante National Monument

Tourists and geologists alike come from all over the world to see and study the magnificent exposures of geologic units displayed in Utah’s Colorado Plateau region. Of particular interest is the Grand Staircase, which is an immense sequence of sedimentary rock layers that stretches south from Bryce Canyon National Park and Grand Staircase–Escalante National Monument […]

The Geology of Zion National Park

Although the geology of the Zion National Park includes nine known exposed formations, Zion is predominately the result of one spectacular unit, the Navajo Sandstone. Zion’s formations represent about 150 million years of mostly Mesozoic-aged sedimentation in a large ancient Jurassic basin. The Navajo is part of a super-sequence of rock units called the Grand Staircase, the time exposed […]

The Vishnu Schist

(exposed in Arizona’s Grand Canyon) The Vishnu schist is part of the Vishnu complex in the exposed basement rocks of the Grand Canyon region. This metamorphic layer was formed by the intrusion of plutonic masses from under the crust and the deposit of sediment from an eroded mountain chain. The oldest rocks in the Vishnu […]

Utah’s Three Types of Volcanoes

Perhaps because it is covered in detail in Grade School and Middle School curriculum, one of the most asked geologic questions I hear from youth has to do with differentiating between the three types of volcanoes. Three Main Types of Volcanoes* The three main types of volcanoes differ in shape, size, and make-up; the differences […]