CRETACEOUS WESTERN INTERIOR SEAWAY DRILLING PROJECT: AN OVERVIEW

Walter E. Dean, and Michael A. Arthur
TIMING OF MID-CRETACEOUS RELATIVE SEA LEVEL CHANGES TN THE WESTERN INTERIOR: AMOCO NO. 1 BOUNDS CORE

Robert W. Scott, M. J. Evetts, P. C. Franks, James A. Bergen, and J. A. Stein
UPPER CRETACEOUS NANNOFOSSIL ASSEMBLAGES ACROSS THE WESTERN INTERIOR SEAWAY: IMPLICATIONS FOR THE ORIGINS OF LITHOLOGIC CYCLES IN THE GREENHORN AND NIOBRARA FORMATIONS

Celeste E. Burns, and Timothy J. Bralower

This book was inspired when I began to teach California geology at the college level and found there were no books suitable for such a course. All the books on the market either were grossly out of date or didn’t discuss the modern understanding of California tectonics. California has one of the most amazing and complex histories of any state in the United States, and so the simplistic approaches of the books currently on the market do not do it justice.

Alaskan-type ultramafic-mafic intrusions occur along a belt that extends from Duke Island to Klukwan in southeastern Alaska and fall into two age groups400 to 440 Ma; and 100 to 118 Ma. Most of the intrusions occur in the Alexander terrane or in the Gravina overlap assemblage, but they are not restricted to these terranes. The Alaskan-type ultramafic bodies range in size from sills only a few meters thick to intrusions about 10 km in maximum exposed dimension. Most of the bodies consist of magnetite-bearing hornblende clinopyroxenite or hornblendite, however many of the larger ones also include dunite, wehrlite, olivine clinopyroxenite, and, in some cases, gabbro.

The Phanerozoic history of North America can be divided into three broad phases:
During the first phase, which lasted from the Late Precambrian to the Triassic, Pangea was under construction. The western continental margin was either a divergent (‘‘passive’’) margin, facing the paleo-Pacific Ocean (Panthalassa) or a backarc basin bordering that ocean, while the eastern margin, beginning in the Middle Ordovician, underwent convergent and collisional tectonism, with the generation of the Appalachian orogen.

Charles Janin является одним из лучших знатоков драгирования в Соединенных Штатах. В своей книге «Gold Dredging in the United States», которую on любезно разрешил перевести на русский язык, он не только излагает оперативные приемы драгирования, разведки месторождений и подготовки их к работам, не только приводит данные о себестоимости дражных работ, но и дает подробное описание дражных конструкций.

Tectonics, Structure Geology, Regional Geophysics 2D Laramide Geometries and Kinematics of the Rocky Mountains, Western U.S.A. Eric A. Erslev    
Complex Proterozoic Crustal Assembly of Southwestern North America in an Arcuate Subduction System: The Black Canyon of the Gunnison, Southwestern Colorado Micah J. Jessup, Karl E. Karlstrom, James Connelly, Michael Williams, Richard Livaccari, Amanda Tyson, and Steven A. Rogers    
Signs From the Precambrian: The Geologic Framework of Rocky Mountain Region Derived From Aeromagnetic Data Carol A. Finn and Paul K. Sims    
Low-Temperature Cooling Histories of the Cheyenne Belt and Laramie Peak Shear Zone, Wyoming, and the Soda Creek-Fish Creek Shear Zone, Colorado Shari A. Kelley

The Mississippi Valley-Type (MVT) Central and East Tennessee (TN) Districts contain economically significant lead-zinc deposits that occur in the Early Ordovician carbonates of the Knox Group. Although both districts share similar host rock, have similar temperatures of formation, and typically fill open spaces of collapse breccias or replace their host carbonates, previous studies may suggest that these ores did not form from the same mineralizing fluids and may have different Pb sources.