Tag Archive for: Utah Geology

With Spring here, we can’t wait to get back out to some of our favorite places. Here’s a bright photo for the season!

Butler Wash, San Juan River, San Juan County, Utah
Photographer: Michael Vanden Berg; © 2011

Petroglyph panel on Jurassic-age Navajo Sandstone, Butler Wash, San Juan River, San Juan County.

Can you “Spot the Rock”? This tucked away sight is no castle of rocks, though its immensity is quite spectacular.
Like us on FACEBOOK or follow us on TWITTER to participate!

UPDATE: Location Revealed

Last week’s “Spot the Rock” photo was of a sinkhole in Big Round Valley, Washington County, just north of the Arizona state line. Can you spot the person for scale in this closeup view of the sinkhole?

This hole formed when the roof of an underlying cave collapsed, but what created the underlying cave? It was likely created when ground water dissolved and carried away the mineral gypsum. The Harrisburg Member of the Kaibab Formation underlies the sinkhole and is known for such gypsum “karst” features elsewhere in the area. Alternatively, or in conjunction with gypsum dissolution, ground water may have dissolved and carried away part of an underlying limestone layer.

A third possible scenario involves a process called sediment piping, where ground water traveling along initially small cracks carries away clay and silt-size particles. In this scenario, fine sediment is carried away in suspension by flowing ground water, and the small cracks can grow to large channels, or pipes. For piping to occur, the removed silt and clay needs a place to be deposited. Therefore, piping features usually end at the base of a river bank or other steep slope. However, the bed of the adjacent Virgin River is about 20 feet (6 meters) higher in elevation than the bottom of the sinkhole. Thus sediment cannot be piped to the river channel. This brings us full circle to needing a cave in limestone or gypsum bedrock to collect sediment.

More information on this location can be found here-http://geology.utah.gov/surveynotes/geosights/sinkhole.htm

By: Tyler Knudsen, Paul Inkenbrandt, William Lund, Mike Lowe, and Steve Bowman

This 116-page report presents the results of an investigation by the Utah Geological Survey of land subsidence and earth fissures in Cedar Valley, Iron County, Utah. Basin-fill sediments of the Cedar Valley Aquifer contain a high percentage of fine-grained material susceptible to compaction upon dewatering. Groundwater discharge in excess of recharge (groundwater mining) has lowered the potentiometric surface in Cedar Valley as much as 114 feet since 1939. Groundwater mining has caused permanent compaction of fine-grained sediments of the Cedar Valley aquifer, which has caused the land surface to subside, and a minimum of 8.3 miles of earth fissures to form. Recently acquired interferometric synthetic aperture radar imagery shows that land subsidence has affected approximately 100 mi² in Cedar Valley, but a lack of accurate historical benchmark elevation data over much of the valley prevents its detailed quantification. Continued groundwater mining and resultant subsidence will likely cause existing fissures to lengthen and new fissures to form which may eventually impact developed areas in Cedar Valley. This report also includes possible aquifer management options to help mitigate subsidence and fissure formation, and recommended guidelines for conducting subsidence-related hazard investigations prior to development.

Although this product represents the work of professional scientists, the Utah Department of Natural Resources, Utah Geological Survey, makes no warranty, expressed or implied, regarding its suitability for a particular use. The Utah department of Natural Resources, Utah Geological Survey, shall not be liable under any circumstances for any direct, indirect, special, incidental, or consequential damages with respect to claims by users of this product.

GET IT HERE

A great read now that Spring is officially here!

stgeorgeutah.com

In a vast, desolate section of the Southern Utah desert, two magnificent natural passageways sit hidden below the surface a half-mile from each other: Peek-A-Boo and Spooky gulches. When linked together, these slot canyons make for a day hike into the depths of a desert underworld that will captivate even the most seasoned adventurer.

READ MORE

kutv.com

Two Highland men who sang and danced as they toppled an ancient rock formation in Goblin Valley State Park pleaded guilty to charges reduced from felonies to misdemeanors in an Emery County courtroom Tuesday.

READ MORE

Bear Lake, Rich County, Utah
Photographer: Jim Davis; © 2011

Storm waves deposit tiny snail and clam shells on a sand bar at Rendezvous Beach State Park, south shore of Bear Lake, Rich County.

parkrecord.com

Francis resident Eric Averett was sitting at his kitchen table Friday morning when he felt a short rumbling and a “boom” sound. That rumbling was a 3.2-magnitude earthquake, which was reported three miles southwest of Woodland.

READ MORE

White Cliffs, Kane County, Utah
Photographer: Tyler Knudsen; © 2011

Small, dome-shaped load structures on a block of Jurassic-age Carmel Formation, White Cliffs, western Kane County.

Tyler Knudsen, one of our geologists here at Utah Geological Survey, talks about our new publication discussing the geologic hazards of the State Route 9 Corridor.

ksl.com

The state has released a new set of maps designed to tip off developers and homeowners to potential geological hazards in communities near Zion National Park.

READ MORE

LISTEN TO INTERVIEW with Tyler Knudsen

Happy Saint Patrick’s Day! This photo may not be green, but I-rish I was there!

Caineville, Wayne County, Utah
Photographer: Robert Ressetar; ©2011

Deltaic sandstone of the Emery Member caps the Blue Gate Member of the Mancos Shale, deposited in a sea during the Cretaceous Period, Caineville, Wayne County.