This bulletin serves not only to introduce the non-geologist to the rich geology of Millard County, but also to provide professional geologists with technical information on the stratigraphy, paleontology, and structural geology of the county. Millard County is unique among Utah’s counties in that it contains an exceptionally complete billion-year geologic record. This happened because until about 200 million years ago the area of present-day Millard County lay near sea level and was awash in shallow marine waters on a continental shelf upon which a stack of fossil-bearing strata more than 6 miles (10 km) thick slowly accumulated. This bulletin summarizes what is known about these strata, as well as younger rocks and surficial deposits in the county, and provides references to scientific papers that describe them in greater detail. Mountains North 30 x 60 (1:100,000-scale) quadrangles. These companion maps and this bulletin portray the geology of Millard County more completely and accurately than any previously published work.

Lake Bonneville: A Scientific Update showcases new information and interpretations about this important lake in the North American Great Basin, presenting a relatively complete summary of the evolving scientific ideas about the Pleistocene lake. A comprehensive book on Lake Bonneville has not been published since the masterpiece of G.K. Gilbert in 1890. Because of Gilbert's work, Lake Bonneville has been the starting point for many studies of Quaternary paleolakes in many places throughout the world. Numerous journal articles, and a few books on specialized topics related to Lake Bonneville, have been published since the late 1800s, but here the editors compile the important data and perspectives of the early 21st century into a book that will be an essential reference for future generations. Scientific research on Lake Bonneville is vibrant today and will continue into the future. - Makes the widespread and detailed literature on this well-known Pleistocene body of water accessible - Gives expositions of the many famous and iconic landforms and deposits - Contains over 300 illustrations, most in full color - Contains chapters on many important topics, including stratigraphy, sedimentology, hydrology, geomorphology, geochronology, isostasy, geophysics, geochemistry, vegetation history, pollen, fishes, mammals, mountain glaciation, prehistoric humans, paleoclimate, remote sensing, and geoantiquities in the Bonneville basin

This report presents the results of the Utah Quaternary Fault Parameters Working Group (hereafter referred to as the Working Group) review and evaluation of Utah’s Quaternary fault paleoseismic-trenching data. The purpose of the review was to (1) critically evaluate the accuracy and completeness of the paleoseismictrenching data, particularly regarding earthquake timing and displacement, (2) where the data permit, assign consensus, preferred recurrence-interval (RI) and vertical slip-rate (VSR) estimates with appropriate confidence limits to the faults/fault sections under review, and (3) identify critical gaps in the paleoseismic data and recommend where and what kinds of additional paleoseismic studies should be performed to ensure that Utah’s earthquake hazard is adequately documented and understood. It is important to note that, with the exception of the Great Salt Lake fault zone, the Working Group’s review was limited to faults/fault sections having paleoseismic-trenching data. Most Quaternary faults/fault sections in Utah have not been trenched, but many have RI and VSR estimates based on tectonic geomorphology or other non-trench-derived studies. Black and others compiled the RI and VSR data for Utah’s Quaternary faults, both those with and without trenches.

This project compiles basic information on the most important geologic and infrastructural factors that would be considered when planning a new high-calcium limestone quarry such as: (1) data on existing pits and prospects, (2) chemical analyses of high-calcium limestone, (3) the extent and spatial distribution of geologic formations having good potential for high-calcium limestone production, (4) references for geologic maps covering existing pits and prospects, and analytical data points, (5) locations of transportation corridors, and (6) locations of cement and lime plants, electric power plants, coal mines, and metal smelters that are large consumers of high-calcium limestone.

Previous studies have shown the Escalante Valley, Utah, is subsiding due to groundwater withdrawal. The magnitude and spatial pattern of this cm/yr.-scale subsidence is mapped with satellite data from a synthetic aperture radar (SAR) using interferometric SAR (InSAR) processing techniques.

Sunrise illuminates Colorado Plateau’s canyon country. In the early morning light, cliffs radiate a rich red glow, and a sculptured panorama of sandstone is revealed in a rich palette of crimson, vermilion, orange, salmon, peach, pink, gold, yellow, and white. Nearby are black, spherical rock marbles (iron concretions) collecting in small depressions, like puddles of ball bearings. These natural spherical balls have been called various names such as iron nodules, iron sandstone balls, or moki marbles. However, we use the name “iron concretion” to describe both the composition (iron oxide that is the dark mineral which cements the sandstone grains) and the formed shape (concretion). What paints the sandstone such rich colors? Why is red a dominant color? Where do the black marbles come from? How did the black marbles form? Is there a relationship between sandstone colors and the marbles? This booklet explores the answers to these questions and poses other questions yet unanswered.