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The Cape Porcupine Complex west of the Strait of Canso in northern mainland Nova Scotia consists of mainly fault-bounded units of metasedimentary, metavolcanic, and granitoid rocks. A previously reported U-Pb (zircon) age of 610 ± 3 Ma from syenogranite combined with petrological characteristics indicates that some of the granitic rocks and possibly an associated body of leucodiorite are Late Neoproterozoic. In contrast, alkali-feldspar granite from a more extensive suite of quartz alkali-feldspar syenite/alkali-feldspar syenite, alkali-feldspar granite/syenogranite, and quartz alkali-feldspar leucosyenite with A-type characteristics yielded an early Ordovician age of 478 ± 3 Ma. Similar A-type chemical characteristics suggest that the metavolcanic unit may be the extrusive equivalent of the Ordovician suite. Similarities in age and petrological characteristics indicate that the Cape Porcupine Complex is linked to rock units in the Antigonish Highlands. The ca. 610 Ma granitic rocks are likely related to plutonic and volcanic rocks of similar age in the Antigonish Highlands interpreted to have formed at a continental margin subduction zone. In contrast the A-type syenitic and metavolcanic rocks are probably related to the compositionally similar West Barneys River plutonic suite and younger volcanic rocks formed in an extensional regime. Such rocks do not occur in adjacent Ganderia or Avalonia in Cape Breton Island or southern New Brunswick, further demonstrating the regional significance of the Canso Fault in tectonic reconstructions. [ABSTRACT FROM AUTHOR]

Organic-walled microfossils (acritarchs) provide age constraints for the previously poorly dated Cambrian and Lower Ordovician turbiditic Goldenville and Halifax Groups in the northern Appalachian Meguma terrane of Nova Scotia and address controversies about stratigraphy and provenance. The oldest exposed formation of the ~8-km-thick Goldenville Group contains the trace fossil Oldhamia, which suggests an age of late Early Cambrian, whereas the coticule-bearing uppermost formation yielded an acritarch species consistent with Middle Cambrian (Epoch 3) age. The conformably overlying ~5-km-thick Halifax Group includes basal pyritiferous units that yielded a Late Cambrian (Furongian) assemblage of acritarch species, providing further confirmation that the underlying manganese-bearing formations are of Cambrian Epoch 3 age, and not Ordovician as recently claimed. Overlying nonpyritiferous formations contain the Early Ordovician graptolite Rhabdinopora flabelliformis flabelliformis and acritarchs of similar age. Samples collected up section from the graptolite occurrence yielded acritarch species that are indicative of the later Tremadocian and Floian. The new fossil data confirm a gap in age of ~30 m.y. between the Halifax Group and the overlying Silurian to Lower Devonian Rockville Notch Group. The new ages are consistent with stratigraphic units defined in regional mapping and support recent interpretation of fundamental differences in depositional and tectonic environments between the north western and southeastern parts of the Meguma terrane. They also provide new constraints on paleogeography of the terrane by confirming age similarities to stratigraphy in north Wales, with which correlation has been proposed previously based mainly on lithological similarities. [ABSTRACT FROM AUTHOR]

Background Three methods of body temperature measurement were compared in owl monkeys: non-contact infrared thermometry, subcutaneous transponder, and rectal probe. Methods Forty owl monkeys ( Aotus sp.) were used. Animals were implanted with subcutaneous microchip transponders. Infrared thermometry was used at three different sites. All measurements were taken and repeated randomly. Results Infrared and subcutaneous measurements did not agree well with rectal thermometry. Subcutaneous and rectal temperatures were highly repeatable, and subcutaneous temperatures were most agreeable to rectal temperatures. Conclusions Further investigation is needed into subcutaneous implant sites and use of different infrared thermometers in this species. [ABSTRACT FROM AUTHOR]

Abstract High-P/low-T metamorphic rocks of the Hammondvale metamorphic suite (HMS) are exposed in an area of 10 km2 on the NW margin of the Caledonian (Avalon) terrane in southern New Brunswick, Canada. The HMS is in faulted contact on the SE with c. 560–550 Ma volcanic and sedimentary rocks and co-magmatic plutonic units of the Caledonian terrane. The HMS consists of albite- and garnet-porphyroblastic mica schist, with minor marble, calc-silicate rocks and quartzite. Pressure and temperature estimates from metamorphic assemblages in the mica schist and calc-silicate rocks using TWQ indicate that peak pressure conditions were 12.4 kbar at 430 °C. Peak temperature conditions were 580 °C at 9.0 kbar. 40Ar/39Ar muscovite ages from three samples range up to 618–615 Ma, a minimum age for high-P/low-T metamorphism in this unit. These ages indicate that the HMS is related to the c. 625–600 Ma subduction-generated volcanic and plutonic units exposed to the SE in the Caledonian terrane. The ages are also similar to those obtained from detrital muscovite in a Neoproterozoic-Cambrian sedimentary sequence in the Caledonian terrane, suggesting that the HMS was exposed by latest Neoproterozoic time and supplied detritus to the sedimentary units. The HMS is interpreted to represent a fragment of an accretionary complex, similar to the Sanbagawa Belt in Japan. It confirms the presence of a major cryptic suture between the Avalon terrane sensu stricto and the now-adjacent Brookville terrane. [ABSTRACT FROM AUTHOR]

Paleoproterozoic granitoid rocks in the Island Harbour Bay area (Kaipokok domain, Makkovik Province, Labrador) are divided into four separate suites on the basis of field relations, petrology, and age. The redefined Island Harbour Bay plutonic suite consists of ca. 1895–1870 Ma dioritic to granitic (mainly granodioritic and granitic) units. The rocks are variably foliated as a result of emplacement under amphibolite-facies conditions in a dextral transpressive regime during Andean-type subduction. The dominant mafic mineral is biotite, and accessory epidote, allanite, and titanite are abundant. The suite is calc-alkalic, but with rare-earth element patterns similar to those of Archean tonalitic–trondhjemitic–granodioritic suites. It is interpreted to have formed deep in an Andean-type magmatic arc at the margin of the Nain continent. In contrast, the younger Hares Islands and Drunken Harbour granites (emplaced at ca. 1805 and 1790 Ma, respectively) were part of widespread late-orogenic magmatic activity in the Makkovik Province. In contrast to the Island Harbour Bay plutonic suite, these units retain igneous textures and are either unfoliated or display magmatic foliation, locally modified by emplacement in active shear zones. The ca. 1716 Ma Blacklers Bight granite varies from porphyritic to equigranular, is fluorite-bearing, and has chemical features approaching those of continental A-type granites. Similar granite occurs farther south in the Makkovik Province, reflecting widespread anorogenic magmatic activity at that time, perhaps related to mafic magma underplating. Variable interaction with Archean (Nain Province) crust by granitic magmas of all three ages is evidenced by ℇ[sub Nd ] values ranging from –7.2 to –2.5.Les roches granitoïdes paléoprotérozoïques de la région de Island Harbour Bay (domaine de Kaipokok, province de Makkovik, au Labrador) sont divisées en quatre suites distinctes selon les relations de terrain, la pétrologie et l'âge. La suite plutonique redéfinie de Island Habour Bay est composée d'unités dioritiques à granitiques (surtout granodioritiques et granitiques), ca. 1895-1870 Ma. La foliation des roches est variable en raison de leur mise en place sous des conditions de faciès de l'amphibolite dans un régime transpressif dextre durant une subduction de type andin. Le minéral mafique dominant est la biotite; l'épidote, l'allanite et la titanite abondent en tant que minéraux accessoires. La suite est calc-alkaline, mais elle possède des patrons des éléments des terres rares semblables à ceux des suites tonalite–trondhjemite–granodiorite de l'Archéen. On croit qu'elle s'est formée à grande profondeur dans un arc magmatique de type andin en bordure du continent Nain. À titre de comparaison, les granites plus jeunes de Hares Island et de Drunken Harbour (respectivement mis en place il y a environ 1805 et 1790 Ma) faisaient partie d'une vaste activité magmatique tardi-orogénique dans la province de Makkovik. Contrairement à la suite plutonique Island Harbour Bay, ces unités ont conservé des textures ignées et elles sont soit sans foliation ou soit avec foliation magmatique, modifiée localement par la mise en place de zones de cisaillement actives. Le granite de Blacklers Bight, ca. 1716 Ma, varie de porphyrique à isogranulaire, il comporte de la fluorine et possède des caractéristiques qui rappellent celles des granites de type A. On retrouve un granite semblable plus au sud dans la province de Makkovik, démontrant qu'à cette époque il y avait une activité magmatique anorogénique généralisée, possiblement reliée à une remontée de magma mafique sous les plaques. L'interaction variable entre la croûte archéenne (province de Nain) et les magmas granitiques des trois âges est mis en évidence par les valeurs de ℇ[sub Nd] variant de –7,2 à –2,5.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

The Meguma Group of southern Nova Scotia has traditionally been subdivided into a lower sand-dominated Goldenville Formation and an upper slate-dominated Halifax Formation interpreted to be deposited on a passive margin. Recent mapping in the Meguma Group, combined with petrography and petrochemistry, has resulted in re-evaluation of its stratigraphy, tectonic setting, and provenance. As previously proposed, the Goldenville and Halifax formations should be formally elevated to "group" status because both units can be subdivided into several formations and members. Thus, the Meguma Group is elevated to "supergroup". The lower part of the Goldenville Group is a metasandstone-dominated unit termed the Church Point formation in the Digby-Yarmouth area and Green Harbour formation in the Pubnico-Chester area. The equivalent units to the northeast (Halifax-Canso area) are subdivided into the Taylors Head and Tangier formations. Several metasiltstone/slate-dominated units are recognized in the lower part of the metasandstone package and include the High Head and Moses Lake members in southwestern Nova Scotia and the Moose River formation in the Halifax-Canso area. The middle part of the Goldenville Group consists of metasandstone/slate termed the Government Point formation (equivalent to the Tancook member) in southwestern Nova Scotia. No equivalent unit is recognized in the Digby-Yarmouth or Halifax-Canso areas. The upper part of the group consists of metasiltstone of the Bloomfield (Digby-Yarmouth area), Moshers Island (Pubnico-Chester area), and Beaverbank (Halifax-Canso area) formations. Units in the overlying slaterich Halifax Group include the Acacia Brook and Bear River formations in the Digby-Yarmouth area, Cunard and Feltzen formations in the Pubnico-Chester area, and Cunard and Glen Brook formations in the Halifax-Canso area. The High Head member contains a distinctive metasiltstone unit with abundant trace fossils including the early Cambrian ichnofossil Oldhamia, suggesting that the Goldenville Group below this member may extend into the Neoproterozoic. The upper part of the Tancook member has yielded an early Middle Cambrian shelf-lithofacies trilobite faunule of Acado-Baltic affinity. The upper part of the Bear River formation locally contains the graptolite Rhabdinopora flabelliformis and acritarch species that are Early Ordovician, suggesting that the underlying Acacia Brook, Cunard, Bloomfield, Moshers Island, and Beaverbank formations are Middle to Late Cambrian, and that a significant unconformity exists between the Halifax Group and the overlying late Ordovician - Early Silurian White Rock Formation. A revised minimum thickness for the Meguma Supergroup is 10 km. Protoliths of the metasandstone units were predominantly immature feldspathic wacke and arenite. Preliminary wholerock geochemical data suggest that most of the clastic material in the Meguma Supergroup was deposited near an active or recently active continental margin, not an Atlantic-style passive continental margin as previously assumed. These new chemical data, combined with detrital muscovite and zircon studies in progress, provide additional constraints on the position of the Meguma terrane in lower Paleozoic continental reconstructions. [ABSTRACT FROM AUTHOR]

40Ar/39Ar dating of whole-rock samples and muscovite separates using age spectrum analysis, and of single muscovite grains using total fusion analysis, yields new insights into the timing of regional metamorphism and sediment provenance in the Late Devonian – Early Carboniferous Horton Group in the Lochaber–Mulgrave area of Nova Scotia. The time of regional metamorphism is constrained to ca. 340–335 Ma by whole-rock spectra from well-cleaved slate and shale samples from the lowermost Clam Harbour River and overlying Tracadie Road formations of the Horton Group. This ca. 340–335 Ma event may have been the result of burial and deformation of the Horton Group by older volcanic and sedimentary rocks of the Guysborough Group, which were overthrust from the south as the result of development of a positive flower structure at a restraining bend along the Cobequid–Chedabucto fault system, the boundary between the Meguma and Avalon terranes. Detrital muscovite ages of ca. 410–380 and ca. 500 Ma were obtained from single-grain analysis and from spectral analysis of separated grains. Whole-rock spectra for two samples from a mylonitic metasedimentary unit in the Cape Porcupine Complex yielded plateau ages of 364 ± 4 and 367 ± 4 Ma, providing a likely source for ca. 370–360 Ma detrital muscovite, ages that may be reflected in some of the age spectrum data. However, the Meguma terrane to the south is the most likely source for most of the detrital muscovite. [ABSTRACT FROM AUTHOR]

We measure new estimates for the galaxy stellar mass function and star formation rates for samples of galaxies at z ∼ 4, 5, 6 and 7 using data in the CANDELS GOODS South field. The deep near-infrared observations allow us to construct the stellar mass function at z ≥ 6 directly for the first time. We estimate stellar masses for our sample by fitting the observed spectral energy distributions with synthetic stellar populations, including nebular line and continuum emission. The observed UV luminosity functions for the samples are consistent with previous observations; however, we find that the observed MUV-M* relation has a shallow slope more consistent with a constant mass-to-light ratio and a normalization which evolves with redshift. Our stellar mass functions have steep low-mass slopes (α ≈ −1.9), steeper than previously observed at these redshifts and closer to that of the UV luminosity function. Integrating our new mass functions, we find the observed stellar mass density evolves from $\log _{10} \rho _{*} = 6.64^{+0.58}_{-0.89}$ at z ∼ 7 to 7.36 ± 0.06 M⊙ Mpc− 3 at z ∼ 4. Finally, combining the measured UV continuum slopes (β) with their rest-frame UV luminosities, we calculate dust-corrected star formation rates (SFR) for our sample. We find the specific SFR for a fixed stellar mass increases with redshift whilst the global SFR density falls rapidly over this period. Our new SFR density estimates are higher than previously observed at this redshift. [ABSTRACT FROM AUTHOR]

The Beaver Harbour Porphyry is a high-level intermediate to felsic granitoid and locally tuffaceous unit with quartz and less abundant feldspar phenocrysts. It forms a fault-bound sliver along the southern margin of the New River belt in southern New Brunswick. A concordant TIMS U-Pb (zircon) age of 551 ± 1.2 Ma shows that the porphyry is of the same age as other high-level plutonic and volcanic units that form most of the New River belt. Chemical data show that these units likely formed in a volcanic-arc environment at an active continental margin. One sample from the porphyry has εNd(t) of -0.5, within the range of other samples from the New River belt and consistent with the interpretation that the belt is part of Ganderia, rather than Avalonia, which generally has more juvenile isotopic signatures. [ABSTRACT FROM AUTHOR]

The repellent efficacies of the U.S. military repellent 33% N,N-diethyl-3-methylbenzamide (deet), 10% and 20% (1S, 2′S) 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (SS220) and 10% and 20% 1-methyl-propyl-2-(hydroxyethyl)-1-piperidinecarboxylate (Bayrepel) cream formulations on human volunteers against the lone star tick Amblyomma americanum (L.) were evaluated in a simulated forest floor environment over a 12-h testing period. At 2-h intervals, volunteers, with repellent applied in a 5-cm-wide band around each ankle, stood for 5 min in plastic tubs containing leaf litter and 100 host-seeking A. americanum nymphs. Ticks were allowed to remain on a volunteer’s feet and ankles for an additional 5 min after the volunteer exited the tub. All repellent formulations provided high levels of protection for the entire 12 h. No ticks crossed 5-cm-wide bands of 20% SS220 and Bayrepel during any challenge, and thus 100% protection was afforded throughout the test. These formulations showed a long-lasting efficacy hitherto unknown in tick repellents intended for use on human skin. [ABSTRACT FROM AUTHOR]

Detrital zircon U-Pb geochronologic studies can potentially provide important new information on the links between terranes in orogens; we report on new data from two terranes in the Appalachian-Caledonide system. The Southern Uplands terrane is a belt dominated by Ordovician-Silurian metasedimentary rocks in the British Caledonides, and is equivalent to the Exploits subzone of the Dunnage Terrane in the Newfoundland Appalachians, from which preliminary detrital zircon data were previously reported. Between Laurentian rocks of the Scottish Highlands, and Ganderian and Avalonian rocks of England and Wales, the terrane is interpreted as representing deposition in the closing Iapetus Ocean. Suggested depositional settings include an accretionary fore-arc, and a back-arc environment attached to Laurentia. Deformation in the terrane records convergence, with significant sinistral transpression. Zircons were extracted from quartzose wackes from three tracts in the northern part of the terrane, deposited in the late Ordovician. Zircons from a sample deposited early in the depositional history display a range of U-Pb ages from Paleoarchean to late Ordovician, including the oldest such grain yet recorded from the British Isles. Neoarchean, Paleoproterozoic, and Mesoproterozoic age populations suggest sources in Laurentia, including the Grenville and Trans- Hudson orogens. The overall age distribution is comparable to that in metasedimentary rocks in the Taconian orogen of W. Newfoundland. Several analyses from a younger sample plot on a discordia line suggesting overprinting of Archean zircon in the Early Paleozoic, consistent with Cambrian tectonothermal reworking of Laurentian detritus in the Grampian orogen, which then acted as the proximal source for detritus. The Meguma Terrane of Nova Scotia lies on the opposite margin of Iapetus, and has been interpreted to represent a fragment rifted from Gondwana. The terrane is dominated by a thick package of turbidites assigned to the Meguma Group (or Supergroup). Two samples were investigated. A sample from the stratigraphically lowest part of the succession in SW Nova Scotia yielded a remarkably uniform population of grains with ages in a single broad cluster in the late Neoproterozoic, plus rare older Proterozoic grains. A sample with a Middle Cambrian depositional age, collected from a rare shelly fossil locality higher in the succession at Tancook Island, yielded a much more diverse population of zircons with peaks in the late Neoproterozoic (~600 Ma), and mid Paleoproterozoic (~2 Ga). [ABSTRACT FROM AUTHOR]