Sources of metals and sulfur in the mineral deposits of central Idaho, USA

A variety of mineral deposits occur in the Paleozoic sedimentary rocks and Late Cretaceous granitic rocks of central Idaho. The main objective of this project is to identify the sources of metals and sulfur in central Idaho ores. Lead isotope compositions of various crustal rocks were determined and compared with the ore lead composition in order to trace sources of lead, and by inference other metals. Sulfur isotope compositions of various sulfide minerals were also determined to trace the sources of sulfur and to explore the coupling or decoupling of metal and sulfur sources. ^ On the basis of lead and sulfur isotope compositions, two groups of ores are recognized: a sedimentary group and an igneous group. The sedimentary group ores are characterized by radiogenic lead and heavy sulfur typical of upper crustal rocks. The sedimentary group ores were formed by meteoric water-dominated hydrothermal systems that leached metals and sulfur from host Paleozoic sedimentary rocks and the underlying Precambrian crystalline basement rocks. The igneous group ores can be divided into two types, the Carrietown-type, and the non Carrietown-type. The Carrietown-type ores are isotopically different from their host granites and are characterized by low uranogenic lead isotope ratios (206Pb/204Pb and 207Pb/ 204Pb) and variable thorogenic lead isotope ratios (208Pb/ 204Pb) typical of lower crustal rocks. The non Carrietown-type ores are similar to host granites and are more radiogenic in their uranogenic lead isotope ratios when compared to the Carrietown-type ores. The differences in the lead isotope compositions of the igneous group ores are attributed to two different phases of magmatic activity. The magmatic phase exposed on the surface involved melting of shallow crustal Precambrian crystalline rocks as well as mid/lower crustal rocks while the underlying phase was derived by melting of mid/lower crustal rocks only. Igneous group ores have both light and heavy sulfur associated with them and it is a function of interaction of hydrothermal fluids with Paleozoic sedimentary rocks. ^ Paleozoic sedimentary rocks and Precambrian basement rocks are the sources of radiogenic lead, and the granites are the sources of light sulfur. Heavy sulfur comes almost entirely from Paleozoic sedimentary rocks. ^

Out of Challenge, Opportunity: Central America's Electric Sector & Key Issues and Recommendations for Enhanced Regional Electric Integration

Taken together, the six nations of Central America count a population of roughly 40 million people and an energy market equal in size to that of Colombia, sufficient to benefit from economies of scale. The region has traditionally been a net importer of hydrocarbons, and hydroelectricity has dominated electric generation. But more recently, thermoelectric generation (diesel and fuel oil) has greatly increased as a percentage of the regional generation market. Progress has been made across the region’s electric sector, beginning with reforms in the 1990s and the 1996 signing of a regional treaty aimed at the development of a regional energy integration project – the Central American Electrical Interconnection System, or SIEPAC. A fundamental SIEPAC goal is to set up a regional electric market and a regulatory system. Indeed, after many years of development, SIEPAC is poised to open a new chapter in Central America’s electric infrastructure and market. But this new era must contend with critical issues such as the need to consolidate the regional electric market, political issues surrounding the venture, and security concerns. Moreover, local conflicts, in different degrees, have become priorities for policymakers, and these are possible barriers to completing the project. The goals of the SIEPAC project and of deepening the broader electric integration process are possible if national and regional decision makers understand that cooperative decision making will produce better results than separate national decision making. Enhanced regional understanding and cooperative decision making, combined with an effort to reorient the terminology and dialogue vis-à-vis energy efficiency in Central America, form the core recommendations of this paper.

Post-revolutionary post-modernism: Central American detective fiction by the turn of the 21st century

Contemporary Central American fiction has become a vital project of revision of the tragic events and the social conditions in the recent history of the countries from which they emerge. The literary projects of Sergio Ramirez (Nicaragua), Dante Liano (Guatemala), Horacio Castellanos Moya (El Salvador), and Ramon Fonseca Mora (Panama), are representative of the latest trends in Central American narrative. These trends conform to a new literary paradigm that consists of an amalgam of styles and discourses, which combine the testimonial, the historical, and the political with the mystery and suspense of noir thrillers. Contemporary Central American noir narrative depicts the persistent war against social injustice, violence, criminal activities, as well as the new technological advances and economic challenges of the post-war neo-liberal order that still prevails throughout the region. ^ Drawing on postmodernism theory proposed by Ihab Hassan, Linda Hutcheon and Brian MacHale, I argued that the new Central American literary paradigm exemplified by Sergio Ramirez's El cielo llora por mí, Dante Liano's El hombre de Montserrat, Horacio Castellanos Moya's El arma en el hombre and La diabla en el espejo , and Ramon Fonseca Mora's El desenterrador, are highly structured novels that display the characteristic marks of postmodern cultural expression through their ambivalence, which results from the coexistence of multiple styles and conflicting ideologies and narrative trends. The novels analyzed in this dissertation make use of a noir sensitivity in which corruption, decay and disillusionment are at their core to portray the events that shaped the modern history of the countries from which they emerge. The revolutionary armed struggle, the state of terror imposed by military regimes and the fight against drug trafficking and organized crime, are among the major themes of these contemporary works of fiction, which I have categorized as perfect examples of the post-revolutionary post-modernism Central American detective fiction at the turn of the 21st century.^

Present-day Pattern Variations in the Central and Eastern Pacific El Nino

El Niño and the Southern Oscillation (ENSO) is a cycle that is initiated in the equatorial Pacific Ocean and is recognized on interannual timescales by oscillating patterns in tropical Pacific sea surface temperatures (SST) and atmospheric circulations. Using correlation and regression analysis of datasets that include SST’s and other interdependent variables including precipitation, surface winds, sea level pressure, this research seeks to quantify recent changes in ENSO behavior. Specifically, the amplitude, frequency of occurrence, and spatial characteristics (i.e. events with maximum amplitude in the Central Pacific versus the Eastern Pacific) are investigated. The research is based on the question; “Are the statistics of ENSO changing due to increasing greenhouse gas concentrations?” Our hypothesis is that the present-day changes in amplitude, frequency, and spatial characteristics of ENSO are determined by the natural variability of the ocean-atmosphere climate system, not the observed changes in the radiative forcing due to change in the concentrations of greenhouse gases. Statistical analysis, including correlation and regression analysis, is performed on observational ocean and atmospheric datasets available from the National Oceanographic and Atmospheric Administration (NOAA), National Center for Atmospheric Research (NCAR) and coupled model simulations from the Coupled Model Inter-comparison Project (phase 5, CMIP5). Datasets are analyzed with a particular focus on ENSO over the last thirty years. Understanding the observed changes in the ENSO phenomenon over recent decades has a worldwide significance. ENSO is the largest climate signal on timescales of 2 - 7 years and affects billions of people via atmospheric teleconnections that originate in the tropical Pacific. These teleconnections explain why changes in ENSO can lead to climate variations in areas including North and South America, Asia, and Australia. For the United States, El Niño events are linked to decreased number of hurricanes in the Atlantic basin, reduction in precipitation in the Pacific Northwest, and increased precipitation throughout the southern United Stated during winter months. Understanding variability in the amplitude, frequency, and spatial characteristics of ENSO is crucial for decision makers who must adapt where regional ecology and agriculture are affected by ENSO.

Present-day Pattern Variations in the Central and Eastern Pacific El Nino

El Niño and the Southern Oscillation (ENSO) is a cycle that is initiated in the equatorial Pacific Ocean and is recognized on interannual timescales by oscillating patterns in tropical Pacific sea surface temperatures (SST) and atmospheric circulations. Using correlation and regression analysis of datasets that include SST’s and other interdependent variables including precipitation, surface winds, sea level pressure, this research seeks to quantify recent changes in ENSO behavior. Specifically, the amplitude, frequency of occurrence, and spatial characteristics (i.e. events with maximum amplitude in the Central Pacific versus the Eastern Pacific) are investigated. The research is based on the question; “Are the statistics of ENSO changing due to increasing greenhouse gas concentrations?” Our hypothesis is that the present-day changes in amplitude, frequency, and spatial characteristics of ENSO are determined by the natural variability of the ocean-atmosphere climate system, not the observed changes in the radiative forcing due to change in the concentrations of greenhouse gases. Statistical analysis, including correlation and regression analysis, is performed on observational ocean and atmospheric datasets available from the National Oceanographic and Atmospheric Administration (NOAA), National Center for Atmospheric Research (NCAR) and coupled model simulations from the Coupled Model Inter-comparison Project (phase 5, CMIP5). Datasets are analyzed with a particular focus on ENSO over the last thirty years. Understanding the observed changes in the ENSO phenomenon over recent decades has a worldwide significance. ENSO is the largest climate signal on timescales of 2 - 7 years and affects billions of people via atmospheric teleconnections that originate in the tropical Pacific. These teleconnections explain why changes in ENSO can lead to climate variations in areas including North and South America, Asia, and Australia. For the United States, El Niño events are linked to decreased number of hurricanes in the Atlantic basin, reduction in precipitation in the Pacific Northwest, and increased precipitation throughout the southern United Stated during winter months. Understanding variability in the amplitude, frequency, and spatial characteristics of ENSO is crucial for decision makers who must adapt where regional ecology and agriculture are affected by ENSO.

Post-Revolutionary Post-Modernism: Central American Detective Fiction by the Turn of the 21st Century

Contemporary Central American fiction has become a vital project of revision of the tragic events and the social conditions in the recent history of the countries from which they emerge. The literary projects of Sergio Ramirez (Nicaragua), Dante Liano (Guatemala), Horacio Castellanos Moya (El Salvador), and Ramon Fonseca Mora (Panama), are representative of the latest trends in Central American narrative. These trends conform to a new literary paradigm that consists of an amalgam of styles and discourses, which combine the testimonial, the historical, and the political with the mystery and suspense of noir thrillers. Contemporary Central American noir narrative depicts the persistent war against social injustice, violence, criminal activities, as well as the new technological advances and economic challenges of the post-war neo-liberal order that still prevails throughout the region. Drawing on postmodernism theory proposed by Ihab Hassan, Linda Hutcheon and Brian MacHale, I argued that the new Central American literary paradigm exemplified by Sergio Ramirez’s El cielo llora por mí, Dante Liano’s El hombre de Montserrat, Horacio Castellanos Moya’s El arma en el hombre and La diabla en el espejo, and Ramon Fonseca Mora’s El desenterrador, are highly structured novels that display the characteristic marks of postmodern cultural expression through their ambivalence, which results from the coexistence of multiple styles and conflicting ideologies and narrative trends. The novels analyzed in this dissertation make use of a noir sensitivity in which corruption, decay and disillusionment are at their core to portray the events that shaped the modern history of the countries from which they emerge. The revolutionary armed struggle, the state of terror imposed by military regimes and the fight against drug trafficking and organized crime, are among the major themes of these contemporary works of fiction, which I have categorized as perfect examples of the post-revolutionary post-modernism Central American detective fiction at the turn of the 21st century.