Report of Investigations No. 135 Oligocene Volcanism and Multiple Caldera Formation in the Chinati Mountains, Presidio County, Texas

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Património mineiro da Serra de Arga - Minho

O A Região da Serra d’Arga apresenta grande diversidade litológica, de depósitos minerais e mineralizações metálicas (Au, Ag, Sn, Nb-Ta, W, Zn, Li), razão pela qual tem sido palco de vários ciclos de aproveitamento extractivo. Destes subsistem diversos vestígios mineiros na paisagem, na organização do território e na memória colectiva das comunidades. O funcionamento mineiro passado revelou ainda um importante património natural - geológico e, bem assim, se expressa num conjunto diversificado de vestígios classificáveis como património cultural e industrial mineiro. Muito embora nesta região as evidências associadas ao aproveitamento de recursos minerais se reconheçam desde o Paleolítico, e ainda com grande incidência na época romana, este trabalho analisa vestígios relativos ao séc. XX, dos quais persistam referências documentais e testemunhos da vivência mineira. No estudo usaram-se métodos multidisciplinares de análise, obtendo: 1) a discriminação de indícios de depósitos filonianos explorados e da implantação das áreas intervencionadas e/ou do edificado; 2) a dispersão espacial de vestígios da actividade extractiva, segundo os principais períodos de intervenção (pela análise documental de arquivos e por inquérito sociológico). A sistemática efectuada e a organização segundo divisões geomineiras regionais permitiu deduzir, respectivamente, faixas e campos mineiros que sustentam uma adequada fundamentação para a avaliação do interesse patrimonial mineiro e geológico associado.The Serra d‘Arga Region is characterized by a great diversity of ore and industrial minerals deposits. The overall set of metallizations includes Au, Ag, Sn, Nb-Ta, W, Zn and Li. Owing to this metalliferous diversity and potentiality the region has been the target for several exploration cycles and mining activities since pre-historical times, which remnants are still very present not only in the traditions and cultural heritage of the local resident people, but also in a lot of material remarks, natural and antropic, and ancient sites where industrial mining heritage and some of its most peculiar remains and assets, are preserved. Evidences of mining activities date from Paleolithic times. Afterwards they were strongly diversified, in what concerns the remarks of Roman activities and some post Medieval-Age thecnologies. However, the main goal of the present study is the mine exploitation occurred during de XX century. The approach follows an analytical perspective dedicated to documental references of technical and administrative nature, which are remaining in state and private-companies archives and museums. The local people collective memoir was accessible through opinion survey, planned interviews and inquiries to ancient miners and some known old, still-living, members of the ancient mining population. The material assets remaining in site or preserved in museological context were also considered and studied using analytical geology and mining archaeology procedures. This multidisciplinary approach allowed: 1) the discrimination of the technological remains and geological exposures of the affected ore deposits as well as the systematics of the mining areas and its remaining edification remarks; 2) the description of space dispersion of the mining activities according to the main mining cycles (recognized in field after documental analysis and sociologic inquiries). This systematics, and the study of the regional geological and mining organization, allowed the definition of geological corridors favorable to mineral exploitation and related mining fields, which sustain an adequate background for the evaluation of mining potentialities and the regional value of natural and industrial-archaeological heritage

Comparative tests of rock drill bits for piston machines

The object of this thesis is to find out the relative cutting qualities of different kinds of rock drill bits. The bits tested were: the regular cross bit, the Z bit of the Southeast Missouri type and the bull bit of the Joplin type. All these bits were made on a No. 5 Leyner sharpener and were tempered as nearly alike as possible. All conditions were kept as nearly uniform as possible during the various tests; air pressure, length of stroke, size of bit, etc., the only variables entering being the difference in bits and personal equation of operators --Introduction, page 1

Bulk power system availability assessment with multiple wind power plants

The use of renewable non-conventional energy sources, as wind electric power energy and photovoltaic solar energy, has introduced uncertainties in the performance of bulk power systems. The power system availability has been employed as a useful tool for planning power systems; however, traditional methodologies model generation units as a component with two states: in service or out of service. Nevertheless, this model is not useful to model wind power plants for availability assessment of the power system. This paper used a statistical representation to model the uncertainty of power injection of wind power plants based on the central moments: mean value, variance, skewness and kurtosis. In addition, this paper proposed an availability assessment methodology based on application of this statistical model, and based on the 2m+1 point estimate method the availability assessment is performed. The methodology was tested on the IEEE-RTS assuming the connection of two wind power plants and different correlation among the behavior of these plants

Gain Modulation by Corticostriatal and Thalamostriatal Input Signals during Reward-Conditioned Behavior.

The cortex and thalamus send excitatory projections to the striatum, but little is known about how these inputs, either individually or collectively, regulate striatal dynamics during behavior. The lateral striatum receives overlapping input from the secondary motor cortex (M2), an area involved in licking, and the parafascicular thalamic nucleus (PF). Using neural recordings, together with optogenetic terminal inhibition, we examine the contribution of M2 and PF projections on medium spiny projection neuron (MSN) activity as mice performed an anticipatory licking task. Each input has a similar contribution to striatal activity. By comparing how suppressing single or multiple projections altered striatal activity, we find that cortical and thalamic input signals modulate MSN gain and that this effect is more pronounced in a temporally specific period of the task following the cue presentation. These results demonstrate that cortical and thalamic inputs synergistically regulate striatal output during reward-conditioned behavior

Derelict mines in the land management: conceptual model for the Lagares Mines - Vila Nova de Paiva

Em Portugal, na última década, as ações dirigidas à reabilitação de espaços mineiros abandonados tiveram principalmente incidência ambiental, ou dedicaram‑se à anulação do risco geotécnico associado às escavações mineiras. Apresenta‑se aqui um modelo conceptual sobre valorização de um local de interesse geológico e mineiro, onde se encara de forma mais abrangente o espaço mineiro devoluto (EMD) como uma unidade territorial com atributos geológicos e industriais relevantes a incluir no ordenamento territorial. A promoção deste EMD representa um extremo de especificidade e diversidade e baseia‑se numa caracterização abrangente, geológica, mineralógica, fisiográfica, arqueológica, sócio‑económica e ambiental, o que potencia variadas formas de usufruto equacionadas, atualmente, para o Couto Mineiro de Lagares. Abstract: In Portugal, in the last decade, programs and actions dedicated to the rehabilitation of abandoned mining areas included environmental purposes and obliteration on hazard related to mine diggings. The conceptual model for the Lagares Mines follows a protocol of procedures which considers the abandoned mine land (AML) as a territorial unit with geological and industrial attributes, which must be considered in land‑use planning. This specific AML represents an extreme of identity and maximal diversity in what concerns the Northern Portugal mining industry. Its holist characterization included geological, mineralogical, physiographic, archaeological, socio‑economic and environmental studies, which suggest and enhance some peculiar components of the land and local management.In Portugal, in the last decade, programs and actions dedicated to the rehabilitation of abandoned mining areas included environmental purposes and obliteration on hazard related to mine diggings. The conceptual model for the Lagares Mines follows a protocol of procedures which considers the mining site (MS) as a territorial unit with geological and industrial attributes, which must be considered in land‑use planning. This specific MS represents an extreme of identity and maximal diversity in what concerns the Northern Portugal mining industry. Its holist characterization included geological, mineralogical, physiographic, archaeological, socio‑economic and environmental studies, which suggest and enhance some peculiar components of the land and local management

Scorodite stability in mine drainage : Northern Portugal

Apresenta-se uma síntese de resultados procedentes de um programa alargado de reconhecimento de neoformações mineralógicas em rejeitos mineiros. Neste caso deu-se especial atenção às paragéneses secundárias em que a scorodite (FeAsO4·2H2O) é fase essencial, ocorrendo sob a forma de cristais isolados, agregados ou ainda em crustificações com diferentes estados de consolidação e níveis de compacidade. Foram selecionados espaços mineiros do N de Portugal, com depósitos hidrotermais de quartzo com sulfuretos metálicos: Castelhão, Argas-Cerquido, Tibães, Adoria e Penedono. Foram analisadas águas de efluente mineiro afetadas pela interação com escombreiras e escavações, e comparadas com águas do fundo regional de cada um dos espaços mineiros. Nos casos estudados, dependendo da interação água – mineral e na sequência da oxidação da arsenopirite, as águas de embebimento e escorrência seguem uma tendência definida até às condições de sobre-saturação e precipitação da scorodite, para um incremento de Eh e decréscimo de pH, a Eh>150 mV e [As] > 90ppb. Abstract:This work synthesizes some results of an extended program of recognition of minerals newly formed in mine wastes and diggings. In this case, it deals with the secondary paragenesis holding scorodite (FeAsO4 • 2H2O) as an essential species, occurring as isolated crystals, aggregates or crusts, with different degrees of consolidation and compaction. The selected mining sites, in Northern Portugal, corresponded to sulphide+quartz hydrothermal veins and mineralizations: Castelhão, Argas-Cerquido, Tibães, Adoria and Penedono. Mining effluents affected by the waste dumps, and the background water in each site were analysed. In the studied effluents, depending on the conditions of water-mineral interaction and arsenopirite oxidation, the composition of affected solutions follow a definite path, till de oversaturation and scorodite precipitation: increasing Eh /decreasing pH at Eh>150mV and As concentration higher than 90 ppb.This work synthesizes some results of an extended program of recognition of minerals newly formed in mine wastes and diggings. In this case, it deals with the secondary paragenesis holding scorodite (FeAsO4 • 2H2O) as an essential species, occurring as isolated crystals, aggregates or crusts, with different degrees of consolidation and compaction. The selected mining sites, in North-ern Portugal, corresponded to sulphide+quartz hydrothermal veins and mineralizations: Castelhão, Argas-Cerquido, Tibães, Adoria and Penedono. Mining effluents affected by the waste dumps, and the background water in each site were analysed. In the studied effluents, depending on the conditions of water-mineral interaction and arsenopirite oxidation, the composition of affected solutions follow a definite path, till de oversaturation and scorodite precipitation: increasing Eh / decreasing pH at Eh>150mV and As concentration higher than 90 ppb

A associação yanomamite-scorodite e a mineralização supergénica de In em detritos mineiros de zonas de cisalhamento com W-Au-As-Zn - Norte de Portugal

"Apresentado no VIII Congresso Nacional de Geologia 2010, Braga, 12-16 Julho"No âmbito de um programa de caracterização mineralógica de escombreiras, em sítios mineiros abandonados, detectou-se uma mineralização invulgar de índio (In) associada a detritos de grão grosseiro, provenientes de antigas lavras subterrâneas, em zonas de cisalhamento com W e/ou Au. A ocorrência mais significativa revela crescimento epitaxial de scorodite sobre núcleos de yanomamite, neoformados em cavidades de corrosão de sulfuretos em blocos soltos. O depósito primário, em Tibães (Braga), corresponde a veios hidrotermais em zonas de cisalhamento, com texturas do tipo fracturação-selagem (“crack-seal").Systematic characterization of waste dumps mineralogy in several abandoned mining sites allowed the detection of an unusual indium (In) mineralization associated with coarse grained debris from small scale underground workings in shear zones with W and/or Au. The most significant occurrence reveals epitaxic overgrowth of scorodite in transition to yanomamite cores, newly formed in corrosion cavities of sulphides in wasted boulders. Primary deposit is a hydrothermally veined and cracksealed shear zone in Tibães (Braga)

Mining traditions in the promotion of Local Heritage. Geological component in the natural and cultural valuing of Serra d’Arga (NW Portugal)

Serie : Cuadernos del Museo Geominero, n.º 12A selecção de conteúdos geológicos e mineiros, que integram o Centro de Interpretação da Serra d’Arga (CISA), apela fundamentalmente à tradição mineira que vigorou durante o Séc. XX e às suas evidências no património natural e cultural. O tema escolhido - “Minerais Úteis”- preconiza, num primeiro momento, a estratégia de promoção do Património Geológico e Mineiro da Serra d’Arga, desencadeada pelo CISA. Neste intuito, foram elaborados e organizados materiais dos quais aqui se faz nota, como sejam fotografias dos minérios mais comuns e ilustrações de infra-estruturas mineiras. Ainda, a integrar uma exposição de minerais e paragéneses, foram seleccionadas amostras tendo em conta o seu fácil reconhecimento pelas gentes locais. Como testemunhos materiais das tradições mineiras potenciam a valorização patrimonial tanto na acepção cultural – mineira – como na diversidade geológica, no que respeita ao tipo de rochas portadoras e sua mineralogia.La selección de los contenidos geológicos y mineros, que integran el Centro de Interpretación de la Sierra d’Arga (CISA), apelan fundamentalmente a la tradición minera que prevaleció durante el siglo XX y sus evidencias en el patrimonio natural y cultural. El tema elegido - “Los minerales útiles” – representa la estrategia iniciada por el CISA para la promoción del Patrimonio Geológico y Minero. Con este objetivo se han preparado y organizado materiales ilustrativos de los cuales se hizo la presente nota, concretamente fotografías de los minerales más comunes y ilustraciones de infraestructuras mineras. Además se hay organizado una muestra de minerales y paragénesis que fueron seleccionados teniendo en cuenta su fácil reconocimiento por la población local. Como prueba material de las tradiciones mineras, dan relieve a la valorización del patrimonio, tanto en el sentido cultural – adonde se incluí la minería – como a la diversidad geológica y mineralógica.The selection of geological and miners content, comprising the Interpretation Center of Arga (ICA), appeals to the mining tradition that prevailed during the XX century and its evidence in the natural and cultural heritage. The chosen theme - “Useful Minerals” - suggests, at first, the strategy of promoting the Geological and Mining Heritage of Arga triggered by ICA. To this end have been prepared and organized photographs of the most common ores and illustrations of mining infrastructure. Also, to integrate a display of minerals and paragenesis, were selected representative samples taking into account its easy recognition by the locals. Those constitutes material evidence of mining tradition, who value the cultural heritage and the geological diversity

A model for the characterization and promotion of forsaken mining sites – The case of Lagares do Estanho, Vila Nova de Paiva

"Apresentado no VIII Congresso Nacional de Geologia 2010, Braga, 12-16 Julho"Apresenta-se um modelo conceptual para a valorização de locais de interesse geomineiro atribuíveis ao Couto Mineiro de Lagares do Estanho. Esta fez-se segundo um protocolo de procedimentos que encara o espaço mineiro (EM) devoluto como uma unidade territorial com atributos geológicos e industriais relevantes para o ordenamento e desenvolvimento territorial. A promoção deste EM representa um extremo de máxima especificidade e diversidade e decorre de uma caracterização abrangente, geológica, mineralógica, fisiográfica, arqueológica, sócio-económica e ambiental, o que potencia variadas formas de usufruto.The conceptual model for promotion of interesting mining sites in the area of Lagares follows a protocol of procedures which considers the abandoned mining space (MS) as a territorial unit with relevant geological and industrial attributes in what concerns territorial planning and land-use management. The assessment to this specific MS represents an extreme of strong identity and maximal diversity and results from an holist characterization – geological, mineralogical, physiographic, archaeological, socio-economical and environmental, which enhance some peculiar trends of space-use