Purpose: Literature on the formation of authigenic rock at cold seeps focuses on the role of microbes in creating geochemically favorable environment for the precipitation of carbonate and barite minerals. Less understood is the pathway that lithified microbial patches of seafloor sediment follow to become rock formations that are identified in strata dating back to the Silurian. In this study I will compare Holocene seep rock from the Gulf of Mexico to Cretaceous carbonates that have been identified as seep rock. Through the study of rock in its early stages of formation to rock that has likely undergone multiple phases of diagenesis I aim to establish a hypothetical sequence of formation of the Cretaceous seep rocks.

This heavily illustrated book contains descriptions and geologic interpretations of photographs (mostly aerial) illustrating the power and magnitude of repeated Ice Age flooding in the Pacific Northwest, as recently as 14,000 years ago. The scale of Ice Age floods was so huge that today it is often difficult to see and appreciate the power and magnitude of such megafloods from ground level. However, from the air, landforms created by the floods often come into clear focus. Aerial images, obtained via unmanned aerial vehicle (drone) as well as fixed-wing airplane, add a new perspective on evidence gathered by dozens of scientists since 1923.

High above the noise and traffic of metropolitan Phoenix, Native American rock art offers mute testimony that another civilization once thrived in the Arizona desert. In the city's South Mountains, prehispanic peoples pecked thousands of images into the mountains' boulders and outcroppings—images that today's hikers can encounter with every bend in the trail. Todd Bostwick, an archaeologist who has studied the Hohokam for more than twenty years, and Peter Krocek, a professional photographer with a passion for archaeology, have combed the South Mountains to locate nearly all of the ancient petroglyphs found in the canyons and ridges. Their years of learning the landscape and investigating the ancient designs have resulted in a book that explores this wealth of prehistoric rock art within its natural and cultural contexts, revealing what these carvings might mean, how they got there, and when they were made. Landscape of the Spirits is the first book to cover these ancient images and is one of the most comprehensive treatments of a rock art location ever published. It conveys the range of different rock art elements and compositions found in the South Mountains—animals, humans, and geometric shapes, as well as celestial and calendrical markings at key sites—through accurate descriptions, drawings, and photographs. Interpretations of the petroglyphs are based on Native American ethnographic accounts and consider the most recent theories concerning shamanism and archaeoastronomy. Written in a simple and accessible style, Landscape of the Spirits is an indispensable volume for anyone exploring the South Mountains, and for rock art enthusiasts everywhere who wish to broaden their understanding of the prehistoric world. It is both an authoritative overview of these ancient wonders and an unprecedented benchmark in southwestern rock art research at a single geographic location.

"This volume contains guides for 34 geological field trips offered in conjunction with the October 2009 GSA Annual Meeting in Portland, Oregon. Showcasing the region's geological diversity, the peer-reviewed papers included here span topics ranging from accreted terrains and mantle plumes to volcanoes, floods, and vineyard terroir. Locations visited throughout Oregon, Washington, and Idaho encompass Astoria to Zillah. More than just a series of maps, the accompanying descriptions, observations, and conclusions offer new insights to the geologic processes and history of the Pacific Northwest - insights that will inspire readers to put their boots on the evidence as they develop their own understanding of this remarkable and dynamic corner of the world."--Publisher's description.