In the course of the hundreds of Rio Chama rafting trips that we've logged during the last 30 years, none of us has ever had a bad trip. Such is the magic of the Rio Chama. No matter the weather, the water level, the season, the crowded Big Eddy boat ramp on a blistering Sunday afternoon, or even the coffee forgotten at home, the Rio Chama remains "The People's River." Its stunning beauty, plus its exceptional camping, user-friendly whitewater, and mostly predictable flows, combine to create one of the Southwest's premiere, multi-day, river running experiences.The spectacular, towering canyon walls of the Wild & Scenic section through the remote Chama River Canyon Wilderness is New Mexico's own "Grand Canyon." The geology of the Rio Chama is so exceptional that this river is ideally suited for a river guide with a geological theme. And so, following the release of the Rio Grande geologic river guide in 2011, we turned our (part-time) attention to the Rio Chama. Although most Rio Chama recreation is focused on the El Vado to Big Eddy stretch, thedecision was easily made to include the entire boatable section, from the highlands in Colorado to the confluence with the Rio Grande, as each section of the river displays its own visual spectacles and assortment of adventures. Plus, the geology is magnificent and diverse along the entire length of the river.

Coated grains have always attracted attention, at first of naturalists, and later of geologists, and the interest in these peculiar bodies was re lated both to their intriguing form and their significance in facies inter pretation and sedimentology and to their relevance to accumulations of hydrocarbons and other mineral deposits. This resulted in numerous publications on this subject, and the intention of this volume is to sum marize the present state of knowledge on coated grains. The idea of the book was to unite some general papers with papers reporting case studies of both recent and ancient coated grains. The organization of the book follows this intention. The papers presented in this volume have been invited by the editor; the theme of the book merits a few words of personal history. The development of studies of coated grains during the last two decades has not only resulted in a great increase in knowledge of recent and ancient environments of coated grain formation, but also numerous important and controversial questions of classification, environmental significance, mineralogical composition etc. of ancient coated grains have arisen. To answer these questions, in 1978 I started the study of many ancient and recent occurrences of coated grains at the Institut fUr Geologie, Ruhr-UniversiUH Bochum, following the invitation of Hans Fiichtbauer and sponsored by the Alexander von Humboldt-Stiftung.