Precambrian non-marine stromatolites in alluvial fan deposits, the Copper Harbor Conglomerate, upper Michigan

Laminated cryptalgal carbonates occur in the Precambrian Copper Harbor Conglomerate of northern Michigan, which was deposited in the Keweenawan Trough, an aborted proto-oceanic rift. This unit is composed of three major facies deposited by braided streams on a large alluvial-fan complex. Coarse clastics were deposited in braided channels, predominantly as longitudinal bars, whereas cross-bedded sandstones were deposited by migrating dunes or linguoid bars. Fine-grained overbank deposits accumulated in abandoned channels. Gypsum moulds and carbonate-filled cracks suggest an arid climate during deposition. Stromatolites interstratified with these clastic facies occur as laterally linked drapes over cobbles, as laterally linked contorted beds in mudstone, as oncolites, and as poorly developed mats in coarse sandstones. Stromatolites also are interbedded with oolitic beds and intraclastic conglomerates. Stromatolitic microstructure consists of alternating detrital and carbonate laminae, and open-space structures. Radial-fibrous calcite fans are superimposed on the laminae. The laminae are interpreted as algal in origin, whereas the origin of the radial fibrous calcite is problematic. The stromatolites are inferred to have grown in lakes which occupied abandoned channels on the fan surface. Standing water on a permeable alluvial fan in an arid climate requires a high water table maintained by high precipitation, or local elevation of the water table, possibly due to the close proximity of a lake. Occurrence of stromatolites in the upper part of the Copper Harbor Conglomerate near the base of the lacustrine Nonesuch Shale suggests that these depositional sites may have been near the Nonesuch Lake.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72022/1/j.1365-3091.1983.tb00713.x.pd

Nonequilibrium Evolution of Correlation Functions: A Canonical Approach

We study nonequilibrium evolution in a self-interacting quantum field theory invariant under space translation only by using a canonical approach based on the recently developed Liouville-von Neumann formalism. The method is first used to obtain the correlation functions both in and beyond the Hartree approximation, for the quantum mechanical analog of the $\phi^{4}$ model. The technique involves representing the Hamiltonian in a Fock basis of annihilation and creation operators. By separating it into a solvable Gaussian part involving quadratic terms and a perturbation of quartic terms, it is possible to find the improved vacuum state to any desired order. The correlation functions for the field theory are then investigated in the Hartree approximation and those beyond the Hartree approximation are obtained by finding the improved vacuum state corrected up to ${\cal O}(\lambda^2)$. These correlation functions take into account next-to-leading and next-to-next-to-leading order effects in the coupling constant. We also use the Heisenberg formalism to obtain the time evolution equations for the equal-time, connected correlation functions beyond the leading order. These equations are derived by including the connected 4-point functions in the hierarchy. The resulting coupled set of equations form a part of infinite hierarchy of coupled equations relating the various connected n-point functions. The connection with other approaches based on the path integral formalism is established and the physical implications of the set of equations are discussed with particular emphasis on thermalization.Comment: Revtex, 32 pages; substantial new material dealing with non-equilibrium evolution beyond Hartree approx. based on the LvN formalism, has been adde

Recent Cnidarian-associated barnacles (Cirripedia, Balanomorpha) from the Brazilian Coast

Basead on extensive collections of cnidarians from Brazilian shallow-water marine environments, new occurrences of four species of associated barnacles are cited, the first three being redescribed; Tne archaeobalanid Conopea galeata, asssociated with the gorgonians Muriceopsis sulphurea, Lophogorgia punicea and Heterogorgia sp from the States of Paraíba, Bahia, Rio de Janeiro and São Paulo; the balanid Megabalanus stultus, associated with the hydrozoans Millepora spp from Paraíba to Alagoas and from the south of Bahia to Rio de Janeiro; the pyrgomatids Megatrema madreporarum, associated with the scleractinian corals Agaricia spp from Paraíba to Alagoas and the south of Bahia, and Ceratoconcha floridanum, associated with the seleractinian coral Mussismilia hispida from Atol das Rodas and Rio de Janeiro.<br>Com base em extensas coleções de cnidários de ambientes marinhos rasos do Brasil, novas ocorrências de quatro espécies da cracas a eles associadas são citadas, e destas três são redescritas: o arqueobalanídeo Conopea galeata, associado às gorgônias Muriceopsis sulphurea, Lophogorgia punicea e Heterogorgia sp , dos Estados da Paraíba, Bahia, Rio de Janeiro e São Paulo; o balanídeo Megabalanus stltus, associado aos hidrozoários Millepora spp, da Paraíba e Alagoas e ao sul da Bahia até o Rio de Janeiro; os pirgomatídeos Megatrema madreporarum, associado aos corais escleractíneos Agaricia sp , da Paraíba e Alagoas e sul da Bahia, e Ce atoconcha floridanum, associado ao coral escleractíneo Mussismilia hispida, do Atol das Rocas e Rio de Janeir

Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC

The article is the pre-print version of the final publishing paper that is available from the link below.Results are presented from searches for the standard model Higgs boson in proton–proton collisions At √s = 7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.1 fb−1 at 7TeV and 5.3 fb−1 at 8 TeV. The search is performed in five decay modes: γγ, ZZ, W+W−, τ+τ−, and bb. An excess of events is observed above the expected background, with a local significance of 5.0 standard deviations, at a mass near 125 GeV, signalling the production of a new particle. The expected significance for a standard model Higgs boson of that mass is 5.8 standard deviations. The excess is most significant in the two decay modes with the best mass resolution, γγ and ZZ; a fit to these signals gives a mass of 125.3±0.4(stat.)±0.5(syst.) GeV. The decay to two photons indicates that the new particle is a boson with spin different from one