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Geology topics

F. Craig Brunstein

Publications and source records attributed to F. Craig Brunstein.

3 recordsLinked to original sources

Historic trail map of the La Junta 1 degree x 2 degree quadrangle, southeastern Colorado and western Kansas

This historic trail map of the La Junta quadrangle contains all or part of eight Colorado and Kansas counties. Many of the historic trails in the La Junta quadrangle were used by Indians long before the white man reached the area. The earliest recorded use of the trails by white men in the quadrangle was in the 1820s when traders brought goods from St. Louis for barter with the Indians and for commerce with the Mexican settlements in New Mexico. The map and accompanying pamphlet include an introduction and the method of preparation used by the authors. The pamphlet includes a description of the early explorers along the Arkansas River and on the Santa Fe Trail, as well as roads established or proposed under General Assembly session law, Colorado Territorial corporations and charters, 1859-1876, and freighting companies. Stage companies that probably operated in the La Junta quadrangle also are described. The authors include a section on railroads in the quadrangle and north of the quadrangle along the Arkansas River. Military and civilian camps, forts, and bases are reported. Moreover, fossils and plants in the quadrangle are described. Indian tribes - Early Man or paleo-Indians, Archaic Indians, prehistoric and historic Indians, and historic Indian tribes in the quadrangle - are reported. Authors include place names within and along freight routes leading to the La Junta quadrangle. A full description of the contents along with three figures can be found in the Introduction.

Colorado, Kansas

Growth-Form Characteristics of Ancient Rocky Mountain Bristlecone Pines (Pinus aristata), Colorado

This report describes and illustrates growth-form characteristics of Rocky Mountain bristlecone pines (Pinus aristata) at several sites in the Rocky Mountains in Colorado. Most of this study concentrates on 1,000- to 2,500-year-old bristlecone pines; however, the report also describes some of the growth-form characteristics of younger trees (about 20 to less than 1,000 years old) in order to show the continuous changes in tree form from youth to old age. To better describe the trees in this study, some tree-structure nomenclature is introduced and a growth-form classification system is provided. Other topics include the relationship of the trees to their substrate and the potential changes in the growth forms of some bristlecone pines due to damage caused by fire, porcupines, impacts from tumbling boulders, and lightning strikes.

Scientific Investigations Report

Climatic significance of the bristlecone pine latewood frost-ring record at Almagre Mountain, Colorado, U.S.A.

From 1900 to 1993, latewood frost rings occurred in 1903, 1912, 1941, 1961, and 1965 in 10 to 21% of the sampled bristlecone pines at Almagre Mountain, Colorado. In early to mid September in each of those years, a severe outbreak of unseasonably cold air from higher latitudes produced a memorable or historic late-summer snowstorm in the western United States. Record subfreezing temperatures during these snowstorms probably caused the latewood frost rings, shortened (by about 1 mo in 1912) already colder than normal growing seasons, and caused crop damage in parts of the Western United States. Latewood frost rings recorded in relatively high percentages of the sampled trees (such as the 1805 event in 61% of sampled trees) were probably caused by multiple severe outbreaks of unseasonably cold air from higher latitudes that occurred from early September (possibly as early as mid- or late August) to mid-September. Analyses of 1900-1992 temperature data for two widely separated Colorado stations, Fort Collins and Colorado Springs, show that average summer (June-September) temperatures during latewood frost-ring years in this century were 1.5 and 2.0°C cooler than normal, respectively. Mountain snowpack probably persisted through these cool summers and was subsequently buried by the earlier than normal snowfall in September. Latewood frost-ring, ring-width, historical, and other data suggest that severe to cataclysmic volcanic eruptions from 1812 to 1835 triggered (1) an extended period of climatic cooling from as early as 1816 or 1817 through the early 1850s in the Southern Rocky Mountains, (2) catastrophic winters in Colorado and Wyoming in 1842-43 and 1844-45, and in the Great Salt Lake Basin in 1836-37, that caused large-scale destruction of bison and other large plains animals, and (3) Little Ice Age alpine glacial advances in about 1850-60 in the western United States.

Colorado