12,536 research outputs found
Cenozoic sedimentary and volcanic rocks of New Zealand: A reference volume of lithology, age and paleoenvironments with maps (PMAPs) and database.
This volume presents descriptive geological data and text about each Cenozoic sedimentary and volcanic geological unit to formation and member level (in some cases) exposed on land in New Zealand, including their lithology, stratigraphic age and inferred environment of deposition or emplacement. These data are illustrated as two types of PMAPS: a present-day paleoenvironment map of New Zealand; and as restored paleoenvironment maps, one for each million years from 65 Ma to the present. These information and data underpin the development of a new Cenozoic paleogeographical model of New Zealand
Pliocene and Pleistocene chronostratigraphy and paleoenvironment of the Central Arctic Ocean, using deep water agglutinated foraminifera
Deep-water agglutinated foraminifera (DWAF) were studied from Cores PS2177-5, PS2200-5, PS2212-3 and PS2185-6; from the R/V POLARSTERN ARK-VIII/3 Cruise in the central Arctic Ocean. The sediments were non-calcareous containing a sparse assemblage of eleven DWAF species. A chronostratigraphic framework is presented for Cores PS2200-5 and PS2185-6. Paleoenvironmental data suggests a bathyal environment (2000-4000m) affected by water masses in the Arctic Ocean. The taxonomy of all of the DWAF found is presented and illustrated. A new species of the Family Trochamminidae; Trochammina lomonosovensis n. sp. is described and illustrated
Geochemical analysis of Cenozoic fossil conifers at high latitudes: Implications for molecular preservation and environmental change
Fossil materials record ancient life and their adapted environment. Arctic plant fossils are critical for our understanding of the Earth’s paleoenvironment when high latitudes were under ice-free conditions. All Arctic plant fossils in this research are conifers, plants conducive for morphological and molecular study because of their incredible genetic stability. Miocene (15 million year old) and Pliocene (5 million year old) conifer leaves were collected from Banks Island, Canada (Williams et al., 2008). Samples were analyzed and compared with Paleocene (60 million year old) and Eocene (45 million year old) samples from Axel Heiberg Island, Canada and with modern equivalent species from Washington D.C., USA (William et al., 2008). This paper has three main sample analyses. First, Pyrolysis-Mass Spectrometry-Gas Chromatography technology was used to detect organic volatile compounds. The amounts and types of organic volatile compounds provide further insights into the molecular preservation of the Miocene and Pliocene fossilized samples. Molecular preservation from this research was compared to previous research that used Scanning Electron Microscope observations of Paleocene and Eocene transverse sections to indicate extraordinary morphological preservation (Yang et al., 2005; Yang et al., 2007). Second, Miocene and Pliocene bulk peat were cross-referenced with known species in the region to reconstruct Arctic environmental changes between 5 million and 15 million years ago. Third, the ratios of three stable compounds were analyzed as biomarkers, essentially benchmarks for plant fossil preservation. However, biomarkers were inconclusive because of complications including age, species type, and environmental conditions. Overall, our analyses provide the first assessments of molecular preservation for these rare Arctic fossils which offer unique material for further paleoclimate analysis
Bibliographic Summary of Arkansas Field Botany
Over 750 references, compiled over the past five years, are presented on floristics, taxonomy, autecology, synecology, species biology, habitat analysis, impact analysis, paleoenvironment, phytogeography, and history of field botany in Arkansas. This bibliography is reported to facilitate efforts to document and interpret the flora, the vegetation, and the natural heritage of Arkansas and to encourage others to participate in that collective effort
Seismic Facies Analysis on 2d Seismic Reflection Profile in Baruna and Jaya Line at North East Java Basin
Two dimension (2D) seismic profile of Baruna and Jaya lines at North-East Java Basin show seismic reflector characteristics that can be used to interpret sediment thickness and continuity. Those reflector characteristics that can be applied for seismic facies analysis that represent depositional environment. This study starts from seismic data processing that using Kirchhoff Post Stack Time Migration method which is 2D seismic profile as result. Seismic reflector characterization has been done to both 2D profiles. Seismic reflector characterization was grouped as (i) individual reflection, (ii) reflection configuration, (iii) reflection termination, (iv) external form. Individual reflection characteristics show high and medium amplitude, medium and low frequency, and continuous. Configuration reflection is continuous with parallel and subparallel type. Reflection termination shows onlap, and external form shows sheet drape. Local mound appearance can be interpreted as paleo-reef. Facies seismic anlysis result for this study area is shelf
Environmental and climatic proxies for the Cañadón Asfalto and Neuquén basins (Patagonia, Argentina): review of middle to upper jurassic continental and near coastal sequences
In this review, we include several proxies (sedimentology, palynology, invertebrates) from the Cañadón Asfalto and Neuquén basins, to infer the environments and regional climatic context during the Middle to Late Jurassic of Patagonia. In central Patagonia, early in the Middle Jurassic, and associated with a magmatic arc, began the sedimentary fi lling of Jurassic continental sub-basins in the Cañadón Asfalto Basin. Lacustrine and fl uvio-deltaic sediments, bearing a continental Middle Jurassic palynobiota, correspond to the Las Chacritas Member, while the sediments and palynobiota from the Late Jurassic Puesto Almada Member (both in the Cañadón Asfalto Formation) indicate a palustrine wetland subenvironment immersed within an arid macroenvironment. Paleoinvertebrates (conchostracans and sponges) of this formation suggest wet-dry cycles in the water bodies they inhabited. The sedimentological information together with the continental and coastal palynomorph assemblages of the back arc Neuquén Basin, allowed distinguishing a complete regressive-transgressive sequence for the Middle Jurassic Lajas Formation. For the Upper Jurassic in this basin, the thick gypsum and anhydrite deposits of the evaporitic coastal Auquilco Formation correlate with extended deposits of eolian sandstones corresponding to the Botucatú paleodesert, and a saltmarsh environment is inferred from the palynofl ora. The palynologic associations from both basins indicate a regional warm climate with seasonal aridity. Climatic conditions would have been drier in the continental interior (Cañadón Asfalto Basin), with strongly seasonally distributed temperatures, and moister in the western coast of the continent (Neuquén Basin), during the marine transgressions.Na presente revisão foram incluídos vários proxies (sedimentologia, palinologia, invertebrados), das bacias de Cañadón Asfalto e Neuquén, para inferir o contexto climático regional e ambiental durante o Jurássico Médio e Superior da Patagônia. Na região central da Patagônia, no início do Jurássico Médio, e associado a um arco magmático, começou o preenchimento sedimentar de sub-bacias continentais jurássicas na bacia Cañadón Asfalto. Os sedimentos flúvio-deitaico e lacustres, tendo uma palinobiota continental do Jurássico Médio correspondente ao Membro Las Chacritas, enquanto os sedimentos e a palinobiota do Jurássico Superior do Membro Puesto Almada (ambos na Formação Cañadón Asfalto) indicam um subambiente palustre úmido imerso em um macroambiente árido. Os paleoinvertebrados (conchostráceos e esponjas) desta formação sugerem ciclos úmidos-secos nos corpos de água por eles habitados. A informação sedimentológica juntamente com as assembleias de palinomorfos continentais e costeiros do “back arc” da bacia Neuquén permitiu distinguir uma sequência completa regressiva-transgressiva para o Jurássico Médio da Formação Lajas. Para o Jurássico Superior, os depósitos de anidrita e gesso espessos da Formação Auquilco costeira evaporítica correlacionam-se com depósitos extensos de arenitos eólicos correspondentes ao paleodeserto Botucatu. Um ambiente “saltmarsh” é inferido a partir da palinoflora. As associações palinológicas de ambas as bacias indicam um clima regional quente com aridez sazonal. As condições climáticas teriam sido mais secas no interior continental (bacia Cañadón Asfalto), com temperaturas fortemente distribuídas de forma sazonal, e úmidas na costa ocidental do continente (bacia de Neuquén), durante as transgressões marinhas.Fil: Volkheimer, Wolfang. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Quattrocchio, Mirta Elena. Universidad Nacional del Sur. Departamento de Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cabaleri, Nora Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geocronología y Geología Isotopica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geocronología y Geología Isotópica; ArgentinaFil: Narvaez, Paula Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; ArgentinaFil: Rosenfeld, U.. Westfälische Wilhelms-universität Münster; AlemaniaFil: Scafati, Laura Haydee. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Melendi, Daniel Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentin
Primeiro registro de madeira de annonaceae para o neógeno da América do Sul, Bacia do Amazonas, Brasil
The relief of the regions of Manaus and Itacoatiara,Central Amazon, is supported by Neogene siliciclastic rocks, boundedat the base and top by lateritic paleosols and covered by quaternary sedimentarydeposits from the Solimões-Amazon river system. This unitis informally assigned to the Novo Remanso Formation, consists ofusually reddish and ferruginized sandstones, conglomerates and pelites,with few identified fossil records, a fact that has hindered its stratigraphicposition, and the paleoenvironmental reconstruction of the lastphase of the Amazon Basin settling. This study describes, for the firsttime, the occurrence of fossil wood in outcroppings of the left bank ofthe Amazon River, where anatomical and morphological data has enabledits characterization to the species level. Thus, the data marks therecord of the Annonaceae in South America, as well as the depositionalprocesses related to incorporation of organic material in the sandylayer and the fossilization processes that allowed its preservation. In anunprecedented way, this study has described Duguetiaxylon amazonicumnov. gen and sp. and provided information on the anatomical andsystematic character, as well as data on plant-insect interaction, and abetter understanding of the family.O relevo das regiões de Manaus e Itacoatiara, na Amazônia Central, é suportado por rochas siliciclásticas neogênicas, delimitadas na base e no topo por paleossolos lateríticos e cobertas por depósitos sedimentares quaternários do sistema fluvial Solimões-Amazonas. Essa unidade é informalmente atribuída à Formação Novo Remanso, constituída geralmente de arenitos avermelhados e ferruginizados, conglomerados e pelitos, com poucos registros fósseis identificados, fato que tem impedido sua posição estratigráfica e a reconstrução paleoambiental da última fase do assentamento da Bacia Amazônica. Este estudo descreve, pela primeira vez, a ocorrência de madeira fóssil em afloramentos da margem esquerda do Rio Amazonas, onde dados anatômicos e morfológicos possibilitaram sua caracterização ao nível da espécie. Assim, os dados marcam o registro de Annonaceae na América do Sul, bem como os processos deposicionais relacionados à incorporação de material orgânico na camada arenosa e os processos de fossilização que permitiram sua preservação. De modo sem precedentes, este estudo descreve Duguetiaxylon amazonicum nov. gen e sp. e fornece informações sobre as características anatômicas e sistemáticas, bem como dados sobre a interação planta-inseto e melhor compreensão da família.Fil: Amaral Soares, Emilio Alberto. Universidade Federal Do Amazonas; BrasilFil: Cabral Kloster, Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Gnaedinger, Silvia Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Centro de Ecología Aplicada del Litoral. Universidad Nacional del Nordeste. Centro de Ecología Aplicada del Litoral; ArgentinaFil: Riker, Silvio Roberto. Serviço Geológico Do Brasil; BrasilFil: Da Cruz Lima, Felipe José. Serviço Geológico Do Brasil ; BrasilFil: Motta, Marcelo Batista. Serviço Geológico Do Brasil; Brasi
The case for dynamic subsidence of the U.S. east coast since the Eocene
The dynamic subsidence of the United States east coast is addressed using the discrepancy between regional and global estimates of sea level, elevation of paleoshorelines, and adjoint models of mantle convection that assimilate plate motions and seismic tomography. The positions of Eocene and Miocene paleoshorelines are lower than predicted by global sea levels, suggesting at least 50 m, and possibly as much as 200 m of subsidence since the end of the Eocene. Dynamic models predict subsidence of the east coast since the end of Eocene, although the exact magnitude is uncertain. This subsidence has been occurring during an overall global sea-level fall, with the eustatic change being larger than the dynamic subsidence; this results in a regional sea-level fall in the absence of land subsidence. Dynamic subsidence is consistent with the difference between eustasy and regional sea level at the New Jersey coastal plain
Present-day climate near the Bunker Cave (Germany): comparison of model simulations to observations
Boundary conditions for the paleoenvironment: Chemical and physical processes in the pre-solar nebula
The first interstellar hydrocarbon ring, cyclopropenylidene (C3H2) is being studied. Both a survey of galactic sources in several C3H2 transitions and a more detailed study of a subset of these sources are under way. In the latter category is a study of the nearby cold dark cloud TMC-1, which is a potential formation site for solar type stars. A spectra is shown of seven rotational transitions which have been observed at the Five College Radio Astronomy Observatory. Three of these were detected for the first time in any astronomical source: the 3 sub 30 to 2 sub 21 transition at 216 GHz, the 2 sub 21 to 1 sub 10 transition at 122 GHz, and the 1 sub 11 to 0 sub 00 transition at 52 GHz. From the data it is apparent that C3H2 is quite spacially extended in typical interstellar molecular clouds, and that at least in TMC-1 it is one of the most abundant organic molecules
- …