Determination of controls on Holocene barrier progradation through application of OSL dating: The Ilha Comprida Barrier example, Southeastern Brazil

Barrier development during the Holocene is studied using the example of the Ilha Comprida, Southeastern Brazil. Aerial photos, facies analysis, and optically stimulated luminescence dating are used to define the barrier emergence and evolution. Optically stimulated luminescence ages and facies successions indicate that the Ilha Comprida probably began as a Holocene transgressive barrier island 6000 years ago, just before the last relative sea-level maximum. Since then the barrier has progradated through the addition of curved beach ridges. Based on beach ridge alignments, six units of growth are identified with two growth directions, transverse and longitudinal. Rates of progradation with transverse growth vary from 0.13 to 4.6 m/year. Rates of longitudinal growth to NE range from 5.2 to 30 m/year. Variation in coastal progradation rates and sediment retention during the last 6000 years is compared with climate, physiography and relative sea-level changes. The physiography, represented by pre-Cenozoic hills, is the major control on sediment retention and alternation between longitudinal and transverse growth. Climate variations, such as the Little Ice Age event, apparently control the formation of ridges types: beach ridges, foredunes, and blowouts. These results allow the use of the Ilha Comprida Barrier as an example to analyze the major controls on barriers progradation. (C) 2011 Elsevier B.V. All rights reserved.

Geochronological data from the Faxinal coal succession, southern Parana Basin, Brazil: A preliminary approach combining radiometric U-Pb dating and palynostratigraphy

A radiometric zircon age of 285.4 +/- 8.6 Ma (IDTIMS U-Pb) is reported from a tonstein layer interbedded with coal seams in the Faxinal coalfield, Rio Grande do Sul, Brazil. Calibration of palynostratigraphic data with the absolute age shows that the coal depositional interval in the southern Parana Basin is constrained to the Sakmarian. Consequently, the basal Gondwana sequence in the southern part of the basin should lie at the Carboniferous-Permian boundary, not within the Sakmarian as previously considered. The new results are significant for correlations between the Parana Basin and the Argentinian Paganzo Basin (302 +/- 6 Ma and 288 +/- 7 Ma) and with the Karoo Basin, specifically with the top of the Dwyka Tillite (302 +/- 3 Ma and 299.2 +/- 3.2 Ma) and the lowermost Ecca Group (288 +/- 3 Ma and 289.6 +/- 3.8 Ma). The evidence signifies widespread latest Carboniferous volcanic activity in western Gondwana. (C) 2007 Elsevier Ltd. All rights reserved.

Dating coeval mafic magmatism and ultrahigh temperature metamorphism in the Anapolis-Itaucu Complex, Central Brazil

Dating granulites has always been of great interest because they represent one of the most extreme settings of an orogen. Owing to the resilience of zircon, even in such severe environments, the link between P-T conditions and geological time is possible. However, a challenge to geochronologists is to define whether the growth of new zircon is related to pre- or post-P-T peak conditions and which processes might affect the (re) crystallization. In this context, the Anapolis-Itaucu Complex, a high-grade complex in central Brazil with ultrahigh temperature (UHT) granulites, may provide valuable information within this topic. The Anapolis-Itaucu Complex (AIC) includes ortho- and paragranulites, locally presenting UHT mineral assemblages, with igneous zircon ages varying between 760 and 650 Ma and metamorphic overgrowths dated at around 650-640 Ma. Also common in the Anapolis-Itaucu Complex are layered mafic-ultramafic complexes metamorphosed under high-grade conditions. This article presents the first geological and geochronological constraints of three of these layered complexes within the AIC, the Damolandia, Taquaral and Goianira-Trindade complexes. U-Pb (LA-MC-ICPMS, SHRIMP and ID-TIMS) zircon analyses reveal a spread of concordant ages spanning within an age interval of similar to 80 Ma with an ""upper"" intercept age of similar to 670 Ma. Under cathodoluminescence imaging, these crystals show partially preserved primary sector zoning, as well as internal textures typical of alteration during high-grade metamorphism, such as inward-moving boundaries. Zircon grains reveal homogeneous initial (176)Hf/(177)Hf values in distinct crystal-scale domains in all samples. Moreover. Hf isotopic ratios show correlation neither with U-Pb ages nor with Th/U ratios, suggesting that zircon grains crystallized during a single growth event. It is suggested, therefore, that the observed spread of concordant U-Pb ages may be related to a memory effect due to coupled dissolution-reprecipitation process during high grade metamorphism. Therefore, understanding the emplacement and metamorphism of this voluminous mafic magmatism is crucial as it may represent an additional heat source for the development of the ultrahigh temperature paragenesis recorded in the paragranulites. (C) 2010 Elsevier B.V. All rights reserved.

U-Pb zircon and (40)Ar-(39)Ar K-feldspar dating of syn-sedimentary volcanism of the Neoproterozoic Marica Formation: constraining the age of foreland basin inception and inversion in the Camaqua Basin of southern Brazil

New U-Pb zircon and (40)Ar-(39)Ar K-feldspar data are presented for syn-sedimentary volcanogenic rocks from the Neoproterozoic Marica Formation, located in the southern Brazilian shield. Seven (of nine) U-Pb sensitive high-resolution ion microprobe analyses of zircons from pyroclastic cobbles yield an age of 630.2 +/- 3.4 Ma (2 sigma), interpreted as the age of syn-sedimentary volcanism, and thus of the deposition itself. This result indicates that the Marica Formation was deposited during the main collisional phase (640-620 Ma) of the Brasiliano II orogenic system, probably as a forebulge or back-bulge, craton-derived foreland succession. Thus, this unit is possibly correlative of younger portions of the Porongos, Brusque, Passo Feio, Abapa (Itaiacoca) and Lavalleja (Fuente del Puma) metamorphic complexes. Well-defined, step-heating (40)Ar-(39)Ar K-feldspar plateau ages obtained from volcanogenic beds and pyroclastic cobbles of the lower and upper successions of the Marica Formation yielded 507.3 +/- 1.8 Ma and 506.7 +/- 1.4 Ma (2 sigma), respectively. These data are interpreted to reflect total isotopic resetting during deep burial and thermal effects related to magmatic events. Late Middle Cambrian cooling below ca. 200 degrees C, probably related to uplift, is tentatively associated with intraplate effects of the Rio Doce and/or Pampean orogenies (Brasiliano III system). In the southern Brazilian shield, these intraplate stresses are possibly related to the dominantly extensional opening of a rift or a pull-apart basin, where sedimentary rocks of the Camaqua Group (Santa Barbara and Guaritas Formations) accumulated.

Not just for romance: applications of speed dating in social work education

In this article we address how a contemporary adaptation of the 'speed dating' model was used for educational purposes with two cohorts of social work students. We outline the dimensions of 'speed dating' as a contemporary social phenomenon, then address how this model relates specifically to groupwork process, and can be used to facilitate social work student learning. The curriculum for two classroom group activities using the 'speed dating' model are outlined, the first to develop university level study skills, the second for debriefing field placement learning experiences. Finally we examine why the 'speed dating' metaphor was successful in provoking a playful yet constructively creative space for students to engage in groupwork process.

Gay and Lesbian Life at Colby 1969-1974

The history of a gay and lesbian student community at Colby seems to point to the difficulty of visibility. For students who were able to find others like themselves, their group of lesbian and gay friends had to remain underground. For students who were grappling with their newly found, socially stigmatized sexuality, the experience was isolating if they did not know where to find others like themselves. This paper seeks to address the social forces that kept sexually variant students from expressing their sexual identities openly on campus. Part of this difficulty is attributable to the compulsory heterosexuality assumed by general American society at the time, manifested in the silence or outright hostility directed against homosexuals. Naturally, Colby students replicated this assumption. Some of the students we interviewed seemed to internalize compulsory heterosexuality, while it was forced upon others. Religion and psychology were two methods of enforcing heterosexuality that were relevant to the people we interviewed. Another significant obstacle to visibility was Colby's location and the nature of Colby's student body. Waterville, unlike more urban cities, did not have a history of gay life, and thus an established gay community or gay identity into which one could be socialized. Colby, as a small, homogeneous and isolated space, posed difficulties in establishing a gay community as the population to draw from was small and regulated.

DEVELOPING A MODEL FOR PEDESTRIAN ROUTE SELECTION AT COLBY

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A SPATIAL ANALYSIS OF IMPERVIOUS SURFACES AT COLBY COLLEGE IN 1965 AND 2006

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SPATIAL ANALYSIS OF COLBY COLLEGE TRAILS: PERKINS ARBORETUM AND RUNNALS HILL

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SOLAR PANEL MODELING ON SUITABLE ROOFS AT COLBY

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ANALYSIS OF FUTURE CONSTRUCTION POSSIBILITIES ON THE COLBY COLLEGE CAMPUS

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Monitoring Surface Displacement of the Colby Green Retaining Pond Dams

The Colby Green is a campus expansion project which began in October of 2003. The construction would result in three new buildings, additional parking, and an elliptical 75,000-squarefoot green southeast of Mayflower Hill Drive. There were also plans for the construction of three run-off management and sediment ponds below the green, to manage flooding of the green. Three drains in the green transport water to the three retaining ponds which slowly disperse water into the surrounding environment. The ponds were created by constructing earthen dams around the drain outlets. The dams are composed of soil, cobbles, and boulders procured from the surrounding excavation site. Unfortunately, earthen dams are susceptible to many types of erosion which result in their failure. In this case the potential for clay and silt from the underlying Presumpscot Formation to mix with the soil in the earthen dams raised concerns with regards to frost action. In order to monitor the surface displacement of the dams I drove 92 poles into the ground in 8 straight lines across the faces of the dams in the fall of 2005. I returned to the sites during and after the spring thaw of 2006, to check for any signs of movement resulting from frost-heave, surface creep, or any other form of mass wasting. Fortunately, there was no recordable sign of movement in the stakes across any of the retaining ponds. The dams appear to be functioning as designed.

DETAILED MAP AND RECREATIONAL SUITABILITY ASSESSMENT OF THE COLBY TRAIL SYSTEM

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Rosenthal, Bob, interviewed by Becky Muller on January 17, 2009: Audio

Some of the themes discussed are: • Civic engagement (2) • The Levine family (2) • High school—private (3) • Colby (4) • Colby—student interaction with Waterville Jews (5) • Dating (6, 7, 18-20) • Life in Waterville (8, 10) • Life in Waterville—movies (12-13) • Colby—Greek life (9) • Colby—administration (9-10) • Occupation—real estate development (10-12, 13, 17) • Camp—Arcadia (13-14) • Military service (16) • Civic engagement (22) • Jewish education (23) • Holidays (23-24)