Burdigalian deposits of the Santa Cruz Formation in the Sierra Baguales, Austral (Magallanes) Basin: Age, depositional environment and vertebrate fossils

Indexación: Web of Science; Scielo.ABSTRACT. A succession of marine and continental strata on the southern flank of Cerro Cono in the Sierra Baguales, northeast of Torres del Paine, can be correlated with stratigraphic units exposed along the southern border of the Lago Argentino region in Santa Cruz Province, Argentina. These include the Estancia 25 de Mayo Formation and the basal part of the Santa Cruz Formation. The lithological correlation is also confirmed by detrital zircon ages (maximum age of 18.23±0.26 Ma) and a rich assemblage of terrestrial vertebrate fossils, biostratigraphically equivalent to a postColhuehuapian, pre-Santacrucian South American Land Mammal Age (SALMA) fauna, suggesting a range of 19 to 17.8 Ma. Similar ages have been obtained from the basal part of the Santa Cruz Formation at Estancia Quién Sabe in southwestern Argentina, supporting the assumption of a regional continuity between these deposits. A measured lithostratigraphic column is presented and the depositional environment is interpreted as a coastal plain with small, meandering rivers and ephemeral floodplain lakes. The sedimentation coincides with intensified uplift of the Patagonian Andes during the ‘Quechua Phase’ of Andean tectonism, which is reflected by a change in paleocurrent directions from northwest to east-northeast. Keywords: Burdigalian, Santa Cruz Formation, Santacrucian SALMA, ‘Notohippidian’ fauna, Meandering rivers.RESUMEN. Una sucesión de estratos marinos y continentales en el flanco meridional del cerro Cono, en la sierra Baguales, al noreste de Torres del Paine, se correlaciona con estratos al sur de la región de lago Argentino en la Provincia de Santa Cruz, República Argentina. Estas unidades incluyen la Formación Estancia 25 de Mayo y la parte basal de la Formación Santa Cruz. La correlación litológica es, además, confirmada por datación de circones detríticos (edad máxima de 18,23±0,26 Ma) y un variado ensamble de vertebrados fósiles terrestres de edad post-Colhuehuapense a pre-Santacrucense en la escala de Edades Mamífero Sudamericanas (EMAS), con un rango temporal de entre 19 a 17,8 Ma. Edades similares han sido reportadas para la parte basal de la Formación Santa Cruz, en estancia Quién Sabe, en el suroeste de Argentina, ratificando la continuidad regional entre estos depósitos. Se presenta una columna estratigráfica y se interpreta el ambiente de depositación como una llanura costera con pequeños ríos sinuosos y lagos efímeros. La edad de sedimentación coincide con el solevantamiento de los Andes Patagónicos durante la 'Fase Quechua', lo que se ve reflejado por un cambio en la dirección de las paleocorrientes desde el noroeste hacia el este-noreste.http://ref.scielo.org/csxwd

Extended Gauge Models and e−e−→W−W−e^-e^- \to W^-W^- at the NLC

We briefly discuss two possible manifestations of the lepton number violating reaction $e^-e^- \to W_i^-W_j^{(*)-}$, which probes the masses and mixings of heavy Majorana neutrinos, at the Next Linear Collider(NLC). Cross sections for this process are shown to be potentially quite large at center of mass energies of order 1-1.5 TeV. (Talk presented at the Santa Cruz Workshop on $e^-e^-$ Physics at the NLC, University of California, Santa Cruz, September 4-5, 1995.)Comment: 9 pages, uuencoded compressed postscript file. To obtain a copy of this paper send e-mail to [email protected]

The Schnitzel Squad

Postcard from Cruz Morey, during the Linfield College Semester Abroad Program at the Austro-American Institute of Education in Vienna, Austri

Patterns of antenal sensilla of Panstrongylus megistus from three Brazilian states

The objective of the present study was to analyze and describe the phenotype of the antennal sensilla of Panstrongylus megistus, one of the epidemiologically most important species of triatomines in Brazil. Specimens from the Brazilian states of Goiás (GO), Minas Gerais (MG), and Rio Grande do Sul (RS) were compared, based on studies of four types of sensilla on three antennal segments: thick-walled trichoid (TK), thin-walled trichoid (TH), bristles (BR), and basiconica (BA). Discriminant analysis allowed the separation of the RS specimens from those of GO and MG. Multivariate discriminant analysis demonstrated that the sensilla of males differed from those of females, the variables with greatest weight being the BA of all three segments and the TK of flagellum 1. The basiconica sensilla were significantly more abundant in females, on all three segments. Antennal sensilla patterns also demonstrated significant differences among P. megistus specimens.Fil: Villela, M. M.. Fundación Oswaldo Cruz; BrasilFil: Catala, Silvia Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Juberg, J.. Instituto Oswaldo Cruz; Brasil. Fundación Oswaldo Cruz; BrasilFil: Silva, I. G.. Universidade Federal de Goiás; BrasilFil: Dias, J. C. P.. Fundación Oswaldo Cruz; Brasi

The development of a Utopian city? Comparing land-and skyscapes in Santa Cruz de Tenerife and San Cristobal de la Laguna

We discuss the peculiar planning of the city of San Cristóbal de La Laguna, in the Canary Island of Tenerife (Spain), when compared to the nearby and essentially contemporary Santa Cruz de Tenerife, which served as a maritime port of the former city. For this we review our previous study of the exact spatial orientation of twenty-one historic Christian churches currently existing in the old part of La Laguna, which we compare with the analysis of six similar buildings located in Santa Cruz, and presented here for the first time. In both cities, we take the spatial orientation of historic churches as good indicators of the original layout of the respective urban lattices. Although we find a clear orientation pattern for La Laguna, which singles out an absolute-value astronomical declination slightly below 20°, pointing to a preferred date close to the July 25th feast-day of San Cristóbal de Licia, in the case of Santa Cruz this trend is not followed. On the contrary, the pattern we find for Santa Cruz, within the uncertainties due to the low statistics, and apart from one equinoctial and one solstitial oriented churches, is consistent with an orographic orientation within the canonic limits of sunrise. This result highlights the uniqueness of the city of La Laguna, and supports the idea suggesting its deliberate planning in the early 16th century.Fil: Gangui, Alejandro. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Belmonte, Juan Antonio. Instituto de Astrofísica de Canarias; Españ

“Natural Born” Disputes in the 2016 Presidential Election

The 2016 presidential election brought forth new disputes concerning the definition of “natural born Citizen.” The most significant challenges surrounded the eligibility of Senator Ted Cruz, born in Canada to a Cuban father and an American mother. Unlike challenges to President Barack Obama’s eligibility, which largely turned on conspiratorial facts, challenges to Cruz’s eligibility turned principally on the law and garnered more serious attention concerning a somewhat cryptic constitutional clause. Understandably, much attention focused on the definition of “natural born citizen” and whether candidates like Cruz qualified. Administrative challenges and litigation in court revealed deficiencies in the procedures for handling such disputes. This paper exhaustively examines these challenges, identifies three significant complications arising out of these disputes, and urges a solution for future presidential elections

Like-Sign Charged Higgs Boson Production in e−e−e^-e^- Collisions at the NLC

We consider the production of a pair of like-sign charged Higgs bosons in $e^-e^-$ collisions at the NLC within the context of several electroweak models with extended symmetry breaking sectors. We find that the rate for this process, which proceeds through $W^-W^-$ fusion, is a very sensitive probe of the nature of these extended Higgs sectors and that the corresponding cross sections can vary by as much as several orders of magnitude at NLC energies. (Talk presented at the Santa Cruz Workshop on $e^-e^-$ Physics at the NLC, University of California, Santa Cruz, September 4-5, 1995.)Comment: 8 pages, uuencoded compressed postscript file. To obtain a copy of this paper send e-mail to [email protected]