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Abstract: New high-resolution chemostratigraphy, in combination with updated biostratigraphy, refines the chronostrati-graphic resolution of the nearly 2 km thick Ordovician section below Anticosti Island. A total of 1414 horizons, spaced [...]

The disputed age of the deep crust of the Colorado Province is central to hypotheses for Paleoproterozoic crystal growth in the region. We studied the high-grade Big Creek Gneiss, southeastern Wyoming, as a potential exposure of pre-1780 Ma basement rocks. New geologic mapping and U-Pb geochronological data indicate that the Big Creek Gneiss exposes a deeper, but coeval, level of the Green Mountain arc relative to the predominantly supracrnstal section to the west. The Big Creek Gneiss is composed of: supracrustal rocks; a ca. 1780 Ma Green Mountain arc-correlative, bimodal intrusive suite; a ca. 1763 Ma extensional(?) bimodal intrusive suite; and widespread ca. 1630 Ma pegmatitic leucogranite. The mafic member of the younger bimodal suite is documented here for the first time. U-Pb zircon ages from migmatite leucosomes indicate penetrative deformation of the Big Creek Gneiss at ca. 1750 Ma. We find that the postarc intrusive suite is mantle involved, implying a second period of crustal growth. Shortening postdates arc magmatism by ~20 m.y., implying that termination of arc magmatism and accretion were separate events. Finally, criteria previously used to constrain the polarity of subduction for the Green Mountain arc are not reliable. We propose two competing models: (1) southward-dipping Green Mountain arc subduction (present coordinates), with slab breakoff--related magmatism following arc accretion; or (2) northward-dipping subduction, with extensional postarc magmatism. In both models, high-temperature deformation coincides with accretion along the Cheyenne belt, and extensional magmatism is an important component of crustal growth. We prefer the northward-dipping subduction model because it can be better integrated with regional tectonic events and published isotopic compositions of the igneous rocks. doi: 10.1130/B30164.1

Mission statements are a critically important piece of business communication from an organization to all of its stakeholders. They must be constantly revised and modified in response to changes within the organization and its environment. This paper examines current mission statements found on the 2008 Fortune 500 list of companies. In an attempt to maintain a reasonable length article, the authors have chosen to analyze the top 50 Fortune firms listed on the CNN Money website located at http://money.cnn.com/magazines/fortune. The results of this study are compared with an article published in the Academy of Managerial Communications Journal in 2001 by the lead author of this paper. Given the current global economic conditions, the authors attempted to determine if such conditions affected the content of current mission statements. First, it appears that many organizations are emphasizing the significance of international or global operations in their mission statements. Today it is relatively easy for even a small firm to develop a webpage and market goods around the world. A second emphasis in current mission statements involves 'going green.' The authors' definition of 'going green' includes the concepts of ethical behavior, being socially responsible, and protecting the environment. In addition to reviewing goals and objectives discussed in mission statements, the authors also analyze the stakeholders included in a typical 2008 mission statement., INTRODUCTION Mission statements are vital communications used by corporations to define themselves to their various stakeholders including customers, employees, creditors, and stockholders. Mission statements can be as short as one [...]

This paper reviews the significance of military cost accounting practices used during the U.S. Civil War. Many of our modern cost accounting practices were derived from those utilized by the U.S. Army from 1861 to 1865. Cost accounting practices were vitally important during this period in order to properly manage all expenses relating to 'men and materials.' Army accounting clerks and quartermasters were taught comprehensive accounting principles and practices at West Point. These practices were also used in military institutions such as the Springfield Armory. The majority of these military cost accounting principles are still in use today. Historical practices such as cost identification, cost classification, and budgeting (cost management) continue to provide modern business managers with the ability to effectively and efficiently control and manage expenditures., INTRODUCTION Modern business firms utilize a variety of cost accounting practices in an effort to manage expenditures and maximize profits. The origin of many of these can be traced to [...]

Paleogenomic research has shown that modern humans, Neanderthals, and their most recent common ancestor have displayed less genetic diversity than living great apes. The traditional interpretation that low levels of genetic diversity in modern humans resulted from a relatively recent demographic bottleneck cannot account for similarly low levels of genetic diversity in Middle Pleistocene hominins. A more parsimonious hypothesis proposes that the effective population size of the human lineage has been low for more than 500,000 years, but the mechanism responsible for suppressing genetic diversity in Pleistocene hominin populations without similarly affecting that of their hominoid contemporaries remains unknown. Here we use agent-based simulation to study the effect of culturally mediated migration on neutral genetic diversity in structured populations. We show that, in populations structured by culturally mediated migration, selection can suppress neutral genetic diversity over thousands of generations, even in the absence of bottlenecks or expansions in census population size. In other words, selection could have suppressed the effective population size of Pleistocene hominins for as long as the degree of cultural similarity between regionally differentiated groups played an important role in mediating intraspecific gene flow. culturally mediated migration | human evolution | Middle Pleistocene | structured populations | agent-based simulation

As the nation woke to the events of the morning of September 11, 2001, the United States seemed to receive an unprecedented wake-up call about the violent world in which [...]

I Tell You a Day Will Come I shall walk quietly to the robin's nest and know the calm blue egg is in me. I shall sit singing and then [...]

A detailed geochemical characterization of 19 representative Proterozoic basement rocks in the Quitovac region in northwestern Sonora, Mexico, has identified two distinct Paleoproterozoic basement blocks that coincide spatially with the previously proposed Caborca and 'North America' blocks. New U-Pb zircon geochronology revises their age ranges, the Caborca (1.78-1.69 Ga) and 'North America' (1.71-1.66 Ga) blocks at Quitovac, and precludes a simple age differentiation between them. In addition, Grenvillian-age granitoids (ca. 1.1 Ga), spatially associated with the Caborca block have been identified at Quitovac. Nd isotopes and major- and trace-element geochemistry support the distinction of these Paleoproterozoic blocks. Granitoids of the 'North America' block are characterized by depleted [epsilon]Nd values (3.4-3.9) and younger Nd model ages (1800-1740 Ma) and have lower [K.sub.2]O, Y, Rb, Ba, Th, REE, and Fe/Mg values than coeval rocks of the Caborca block. The Caborca block granitoids are likewise characterized by slightly less depleted [epsilon]Nd (0.6-2.6) and older Nd model ages (2070-1880 Ma). Despite the subtle differences, granitoids from both the Caborca and 'North America' blocks exhibit island arc-like affinities. We propose that the Proterozoic basement rocks from the Quitovac region are an extension of the Proterozoic crustal provinces in the southwestern United States. Specifically, rocks of the Caborca block exhibit an affinity to rocks of either the Yavapai province or the Mojave-Yavapai transition zone, whereas rocks of the 'North America' block have signatures similar to those of the Mazatzal province or possibly the Yavapai province of Arizona. The new isotopic ages and geochemical data do not support the existence of the Late Jurassic Mojave-Sonora megashear at Quitovac, as originally proposed. However, the Quitovac region accounts only for a small fraction of the Proterozoic basement in Sonora, so these findings do not eliminate the possibility of a megashear elsewhere in northern Sonora. Our new data create the possibility of alternative hypotheses for the distribution of Paleoproterozoic crustal provinces in southwestern North America that affect reconstructions of the original southwestern margin of Laurentia, and reduce uncertainties in the configuration, timing, and existence of the Proterozoic supercontinent, Rodinia. Keywords: isotopes, geochemistry, geochronology, tectonics, Proterozoic, Sonora, Mexico.

Precise U-Pb baddeleyite dating of mafic igneous rocks provides evidence for a widespread and synchronous magmatic event that extended for >2400 km along the western margin of the Neoproterozoic Laurentian craton. U-Pb baddeleyite analyses for eight intrusions from seven localities ranging from the northern Canadian Shield to northwestern Wyoming-southwestern Montana are statistically indistinguishable and yield a composite U-Pb concordia age for this event of 780.3 [+ or -] 1.4 Ma (95% confidence level). This 780 Ma event is herein termed the Gunbarrel magmatic event. The mafic magmatism of the Gunbarrel event represents the largest mafic dike swarm yet identified along the Neoproterozoic margin of Laurentia. The origin of the mafic magmatism is not clear, but may be related to mantle-plume activity or upwelling asthenosphere leading to crustal extension accompanying initial breakup of the supercontinent Rodinia and development of the proto-Pacific Ocean. The mafic magmatism of the Gunbarrel magmatic event at 780 Ma predates the voluminous magmatism of the 723 Ma Franklin igneous event of the northwestern Canadian Shield by ~60 m.y. The precise dating of the extensive Neoproterozoic Gunbarrel and Franklin magmatic events provides unique time markers that can ultimately be used for robust testing of Neoproterozoic continental reconstructions. Keywords: mafic magmatism, geochronology, dike swarms, rifting, Rodinia.

A study to cross the history of Andean women with that of Andean peasantry under Spanish rule by focusing on the gendered patterns of population decline, mita migration and economic adaptation in Altiplano province is attempted. The effects of the large-scale economic and social phenomena on the lives of the ordinary women are examined.

Old age is a time characterized by loss - loss of family and friends, work-identity, and independence. Isolation and diminishing physical capabilities contribute significantly to feelings of helplessness and lack […]

Seven analyses from two samples of the Lower Banded series of the Stillwater Complex, Montana, yielded a U-Pb zircon-baddeleyite age of 2705 [+ or -] 4 Ma. A more precise age of 2704 [+ or -] 1 Ma is obtained if we regress only five of seven analyses. In either case, the age is in very good agreement with the previously reported Sm-Nd mineral isochron age of 2701 [+ or -] 8 Ma for a gabbro from the Lower Banded series. Noncumulate mafic sills and dikes that immediately underlie the Stillwater Complex are separated into five compositional groups. U-Pb zircon ages for a group 1 gabbronorite (2711 [+ or -] 1 Ma) and a group 3 mafic norite (2703 [+ or -] 10 Ma) are comparable to previously reported U-Pb zircon ages for a group 1 diabase (2713 [+ or -] 3 Ma) and a group 4 high-Ti norite (2712 [+ or -] 3 Ma). Although group 2 high-Mg gabbronorite and group 6 olivine gabbro have not yet yielded significant amounts of zircon, baddeleyite, or sphene, mineral separates from group 2 yielded a four-point Pb-Pb internal isochron age of 2704 [+ or -] 25 Ma, and separates from group 6 yielded a Sm-Nd internal isochron age of 2706 [+ or -] 64 Ma, indicating that these groups are at least contemporaneous with intrusion of the Stillwater Complex. These results indicate that groups 1 and 4 of the associated sills and dikes are perhaps slightly older than the complex and that groups 2, 3, and 6 may be coeval with it, supporting the idea that these three groups are the best candidates for a Stillwater parent magma, a conclusion previously presented on the basic of detailed mineralogic and and geochemical evidence.

The analysis of a group of 26-29 wild mantled howling monkeys (Alouatta palliata) present in the Isla de Ometepe, Nicaragua, to determine the trends of subgrouping, activity, and partner preferences, is given. The observations of the study are discussed and it is suggested that perseverance of strong male-male and male-female partner preferences in mantled howlers explains the consistency of considerably large multimale-multifemale groups.

Introduction The defeat of the Sandinista Front for National Liberation (FSLN) on February 25, 1990, provided Nicaragua with a rare opportunity to negotiate fundamental changes in civil-military relations. As a [...]