Tabbys Peak in the Cedar Mountains, Tooele County, Utah.
Photographer: Don Clark
About 40 million years ago, magma intruded to form a large dike. While cooling, the magma shrank and fractured into a six-sided column pattern, resulting in the blocky appearance of the weathered andesite at Tabbys Peak in the Cedar Mountains, Tooele County.
Dinosaurs were significant tourists, back in the day. Some enjoyed the area so much, they decided to stay. A few of them were even known to throw their weight around! The Grand Staircase-Escalante National Monument (GSENM) has provided a treasure trove of dinosaur discoveries. Of the 39 new dinosaur discoveries worldwide, nine have come from the GSENM!
Mesas, buttes, and canyons in the east-central area of the San Rafael Swell, Emery County, Utah.
Photographer: Tom Chidsey
The La Sal Mountains viewed through Mesa Arch in the Island in the Sky District of Canyonlands National Park, San Juan County, Utah
Photographer: Taylor Boden
Mount Magog (9,750 feet) and White Pine Lake, Cache National Forest, Cache County, Utah
Photographer: Ken Krahulec
“Prowling Coyote” in Fantasy Canyon, Uintah County, Utah
Photographer: Jim Davis
Goosenecks State Park, San Juan County, Utah
Photographer: Bill Lund
Deeply incised meanders form the goosenecks of the San Juan River at Goosenecks State Park, San Juan County.
Goblin Valley State Park, Emery County, Utah
Photographer: Keith Beisner
At Goblin Valley State Park on the southeast side of the San Rafael Swell, morning sun gives Wild Horse Butte an ethereal glow. The butte exposes all four geologic units present in the park: the Entrada Sandstone and Curtis, Summerville, and Morrison Formations. These strata record profound changes in Utah’s geography during Middle and Late Jurassic time, including the existence of coastal sand dunes, inundation by a shallow inland sea, and then uplift, erosion, and sediment deposition in stream channels and flood plains.
Snow Canyon State Park,
Washington County, Utah
Photographer: Tyler Knudsen
About 27,000 years ago, lava flowed on top of the Navajo Sandstone, forming black “ropey” basalt in Snow Canyon State Park, Washington County.
Utah is peppered with volcanoes and other signs of the hot molten rock (magma) that forms within the crust beneath us. Magma, less dense than the surrounding solid rock, rises where it can and intrudes into adjacent rock to form laccoliths, batholiths, dikes, and sills upon cooling. It can also extrude onto the surface as lava, sometimes explosively ejecting lava fragments and ash. The resulting igneous rocks can vary widely in appearance.
By: Janice M. Hayden
The Yellowjacket Canyon 7.5′ quadrangle is divided north-south by the Sevier fault zone with the lower Navajo Sandstone and older rocks creating the Vermilion Cliffs step of the Grand Staircase on the up-thrown block to the east, and the upper Navajo Sandstone and younger rocks creating the White Cliffs step of the Grand Staircase on the down-dropped block to the west. Exposed strata range from the Triassic Petrified Forest Member of the Chinle Formation to the Jurassic Co-op Creek Limestone Member of the Carmel Formation. Eoloian sand dunes, including those of Coral Pink Sand Dunes State Park, stretch northeast to southwest across the map area.
This CD contains geographic information system (GIS) files in ESRI file geodatabase and shapefile formats. Also included are two plates-the geologic map at 1:24,000 and the explanation sheet-both in PDF format. The latest version of Adobe Reader is required to view the PDF files. Specialized GIS software is required to use the GIS files.
M-256DM……….. $24.95
The Utah Geological Survey (UGS) is a division of the Utah Department of Natural Resources. Several specialized programs comprise the UGS: Data Management, Energy & Minerals, Geologic Hazards, Geologic Information & Outreach, Geologic Mapping, Groundwater & Wetlands, and Paleontology.
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