985 resultados para East-central Nevada


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Dissociated remains of the acanthodian Poracanthodes punctatus are described from Upper Silurian (Pridoli) limestones of the Roberts Mountains Formation at Pete Hanson Creek, Eureka County, Nevada. The vertebrate microremains in sample residues comprise scales, a dentigerous jaw bone fragment, and a fin spine fragment assigned to P. punctatus, plus one possible acanthothoracid placoderm scale. Some macroremains from the same locality are also assigned to P. punctatus. This taxon has been nominated as, a zone fossil for the Silurian vertebrate biozonal scheme, and its presence has been recorded throughout the circum-Arctic region. Identification of the taxon in Nevada extends its known geographic range.

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This paper represents the first detailed study of the Transversarium-Bifurcatus Zone boundary in the Algarve. The boundary studied in the Peral area is associated with a stratigraphic discontinuity, whose hiatus partially affects the Transversarium-Bifurcatus Zones. A discontinuity was also recognized in the Bifurcatus-Birnammatum Zone boundary, which can be correlated with the traces of a Type II unconformity, which separates cycles 4.3-4.4 in HAQ et al. (1987), present on the South Iberian palaeomargin. An analysis was made of the ecostratigraphic evolution in the interval between the uppermost Transversarium Zone and the lower part of the Bimammatum Zone on the basis of the faunal spectra obtained. We conclude that ammonites are the most tolerant cephalopods to the ecological stress caused by the increase of inflows and the decrease of the shelf's ecospace. Benthic fauna decreased considerably in these conditions. A relatively abundant and diversified fauna ofDichotomoceras is noteworthy among the ammonites collected, as this genus was previously little known in the Algarve.

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On the basis of geologic, petrologic, and U-Pb geochronologic data the basement rocks in the east-central part of the Rondonia Tin Province (RTP, southwestern Amazonian craton) are grouped into five lithologic associations: (1) tonalitic gneiss (1.75 Ga); (2) enderbitic granulite (1.73 Ga); (3) paragneiss; (4) granitic and charnockitic augen gneisses (1.57-1.53 Ga); and (5) fine-grained granitic gneiss and charnockitic granulite (1.43-1.42 Ga). The first three are related to development of the Paleoproterozoic Rio Negro-Juruena Province and represent the oldest crust in the region. The tonalitic gneisses and enderbitic granulites show calc-alkaline affinities and Nd isotopic compositions (initial epsilon(Nd) = +0-1 to -1.5; T-DM of 2.2-2.1 Ga) that suggest a continental arc margin setting for the original magmas. The paragneisses yield T-DM values of 2.2-2.1 Ga suggesting that source material was primarily derived from the Ventuari-Tapajos and Rio Negro-Juruena crusts, but detrital zircon ages and an intrusive granitoid bracket deposition between 1.67 and 1.57 Ga. The granitic and charnockitic augen gneisses show predominantly A-type and within-plate granite affinities, but also some volcanic arc granite characteristics. The initial epsilon(Nd) values (+0.6 to +2.0) indicate mixing of magmas derived from depleted mantle and older crustal sources. These rocks are correlated to the 1.60-1.53 Ga Serra da Providencia intrusive suite that reflects inboard magmatism coeval with the Cachoeirinha orogen located to the southeast. The fine-grained granitic gneiss and charnockitic granulites represent the first record of widespread magmatism at 1.43-1.42 Ga in northern Rondonia. Their geochemical signatures and the slightly positive initial epsilon(Nd) values (+0.7 to +1.2) are very similar to those of the most evolved granites of the calc-alkaline Santa Helena batholith farther southeast. U-Pb monazite and Sm-Nd whole-rock-garnet ages demonstrate that a high-grade tectonometa-morphic episode occurred in this region at 1.33-1.30 Ga. This episode attained upper-amphibolite conditions and is interpreted as the peak of the Rondonian-San Ignacio orogeny. The U-Pb and Sm-Nd data presented here and data published on rapakivi granites elsewhere indicate that the east-central part of the RTP is a poly-orogenic region characterized by successive episodes of magmatism, metamorphism, and deformation between 1.75 and 0.97 Ga. (C) 2002 Elsevier B.V. B.V. All rights reserved.

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This article deals with the European minorities in the period between the two world wars and with their final expulsion from nation-states at the end of World War II. First, the tensions which arose between the organised minorities and the successor states of the Habsburg Monarchy are accounted for primarily by the argument that the various minorities located within the successor states had already undergone a comprehensive processes of nationalisation within the Habsburg Empire. Therefore they were able to resist assimilation by the political elites of the new titular nations (Czechs, Poles, Rumanians, Serbs). A second topic is that of the use made of the minorities issue by Adolf Hitler to help achieve his expansionist aims. The minorities issue was central to the international destabilisation of interwar Europe. Finally, the mass expulsion of minorities (above all, Germans) after the end of the war is explained by strategic considerations on the part of the Allied powers as well as involving the nation-state regimes. It is argued, against a commonly held view, that German atrocities during the period of occupation had little to do with the decision to expel most ethnic Germans from their territories of settlement in Poland, Czechoslovakia and Yugoslavia. The article shows that it is necessary to treat national minorities in the first half of the twentieth century as a single phenomenon which shares similar features across the various nation-states of East-Central Europe.

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v.6:no.20(1938)

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With the EU-enlargement process well underway, this paper focuses on social citizenship as a conceptual frame for analyzing the restructuring of social institutions in applicant countries in East Central Europe. So far, comparative welfare state analysis has concentrated mainly on the developed economies of the OECD-countries; there is little systematic analytical work on the transitions in post-communist Europe. Theoretically, this paper builds on comparative welfare state analysis as well as on new institutionalism. The initial hypothesis is built on the assumption that emerging patterns of social support and social security diverge from the typology described in the comparative welfare state literature inasmuch as the transformation of postcommunist societies is distinctly different from the building of welfare states in Europe. The paper argues that institutionbuilding is shaped by and embedded in the process of European integration and part of governance in the EU. Anticipating full membership in the European Union, the applicant countries have to adapt to the rules and regulations of the EU, including the "social acquis." Therefore, framing becomes an important feature of institutional changes. The paper seeks to identify distinct patterns and problems of the institutionalization of social citizenship.

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At head of title: State of Illinois. Department of registration and education. Division of the state geological survey.

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"March 1957."