Diverted from its former course to the Pacific Ocean by basalt flows in Gem Valley, Idaho, the Bear River presently flows south into the Bonneville Basin. Constraining the timing of the river's diversion is pivotal to understanding the hydrologic budgets, and thus the climatological implications of the Bonneville Basin lakes. This study employs strontium (Sr) isotopes in mollusc fossils as a tracer of the Bear River water that entered Lake Thatcher, a small, closed-basin lake into which the redirected river flowed en route to the Bonneville Basin. The Sr ratios, combined with the temporal control afforded by amino acid geochronology and tephrochronology, were compared to mixing models constructed from the 87Sr/86Sr composition of the modern rivers draining into the basin to stimulate the Sr isotropic composition of Lake Thatcher. Strontium ratios of six fossil molluscs collected from the lower-most exposed section of the Main Canyon Formation (MCF) indicate that during the early Quaternary (>620 ka), Thatcher Basin was occupied by a locally fed, isotopically-enriched (87Sr/86Sr=0.71309) lake and did not receive input form the Bear River. Eleven fossils, collected from the uppermost exposed section of the MCF, indicate at least three course changes of the Bear River in the late Quaternary: diversion into the basin around 140 ka, diversion from the basin sometime between 140 and 100 ka, and finally diversion back into the basin around 50 ka. Hydrologic modeling of Thatcher Basin with and without the input of the Bear River suggests that water from both a Bear River-influenced or a locally fed lake is capable of filling the basin and causing it to spillover into the adjacent Bonneville Basin. Thus, the Bonneville Basin may have been receiving water from either the Bear River, or the Thatcher Basin rivers, significantly earlier than the ~30 ka previously proposed. Additional hydrologic modeling in Thatcher Basin suggests that a two-fold reduction in the effective precipitation as compared to modern conditions would be required to lower a locally fed Lake Thatcher the ~30 m necessary to account for the paleosol exposed in the uppermost MCF.

<p> Study of the ecology of concretion and host sediment fossils from a shell bed in middle Bajocian clays of northwestern Germany indicates a predominantly epifaunal suspension-feeding community living on a firm mud bottom. The shell bed, firm bottom and low turbidity required by suspension feeders suggests a hiatus or reduced sedimentation at the time. Depth estimates of 50 to 150 m are indicated by ammonite and belemnite siphuncle and septal strength indices.</p> <p> Preservation of calcitic fossils is excellent in both concretions and host sediments. Aragonitic fossils show good preservation in the concretions. Aragonite has been replaced by at least two generations of calcite. Preservation in the host sediments is poor. Pyrite is common in void spaces of concretion fossils but less so in those from the host sediments.</p> <p> Eight concretions were studied, containing numerous Stephanoceras mutabile (macroconch) and Stephanoceras quenstedti (microconch). These are of opposite sexes but are not a dimorphic pair.</p> <p> Distribution of shell debris and other fossils within the concretions suggests that the ammonites were swept by currents into shallow depressions in the sea floor lined with shell debris. Such depressions have been observed in modern sediments as the result of the feeding activity of rays. The presence of currents is indicated by the southwest orientation of belemnite rostra in the host sediments. Carbonate content of concretion matrix is high indicating concretion growth in very fluid muds. This contrast with the firm bottom indicated by fossil ecology suggests rapid burial of the benthic community by either a mudflow or a sudden, large increase in sedimentation. Concretion growth was initiated by decomposition of organic matter within the mud.</p> / Thesis / Master of Science (MSc)

This thesis makes several contributions to improve our understanding of the Neoproterozoic Paleobiology. In chapter 1, a comprehensive quantitative analysis of the Ediacara fossils indicates that the oldest Ediacara assemblage "the Avalon assemblage" already encompassed the full range of Ediacara morphospace. A comparable morphospace range was occupied by the subsequent White Sea and Nama assemblages, although it was populated differently. In contrast, taxonomic richness increased in the White Sea assemblage and declined in the Nama assemblage. The Avalon morphospace expansion mirrors the Cambrian explosion, and both may reflect similar underlying mechanisms. Chapter 2 describes problematic macrofossils collected from the Neoproterozoic slate of the upper Zhengmuguan Formation in North China and sandstone of the Zhoujieshan Formation in Chaidam. Some of these fossils were previously interpreted as animal traces. Our study of these fossils recognizes four genera and five species. None of these taxa can be interpreted as animal traces. Instead, they are problematic body fossils of unresolved phylogenetic affinities. Chapter 3 reports stable isotopes of the Zhamoketi cap dolostone atop the Tereeken diamictite in the Quruqtagh area, eastern Chinese Tianshan. Our new data indicate that carbonate associated sulfate (CAS) abundance decreases rapidly in the basal cap dolostone and δ34SCAS composition varies between +9â ° and +15â ° in the lower 2.5 m. In the overlying interval, CAS abundance remains low while δ34SCAS rises ~5â ° and varies more widely between +10â ° and +21â °. δ34Spy is typically greater than δ34SCAS measured from the same samples. We propose that CAS and pyrite were derived from two isotopically distinct reservoirs in a chemically stratified basin. Chapter 4 studies δ13C, δ18O, δ34SCAS, and δ34Spy of the Zhoujieshan cap carbonate that overlies the Ediacaran Hongtiegou glaciation. The Zhoujieshan cap dolostone shows positive δ13C values (0 â 1.7â °). δ34SCAS shows rapid stratigraphic variations from +13.9 to +24.1â °, probably due to relatively low oceanic sulfate concentrations. δ34Spy shows a steady stratigraphic trend. Thus, the δ34SCAS and δ34Spy trends are decoupled from each other. The decoupling of δ34SCAS and δ34Spy trends suggests that CAS and pyrite were derived from different sulfur pools, which were probably due to the postglacial basin stratification. / Ph. D.

Yes / The Mesolithic-to-Neolithic transition marked the time when a hunter-gatherer economy gave way to agriculture, coinciding with rising sea levels. Bouldnor Cliff, is a submarine archaeological site off the Isle of Wight in the United Kingdom that has a well-preserved Mesolithic paleosol dated to 8000 years before the present. We analyzed a core obtained from sealed sediments, combining evidence from microgeomorphology and microfossils with sedimentary ancient DNA (sedaDNA) analyses to reconstruct floral and faunal changes during the occupation of this site, before it was submerged. In agreement with palynological analyses, the sedaDNA sequences suggest a mixed habitat of oak forest and herbaceous plants. However, they also provide evidence of wheat 2000 years earlier than mainland Britain and 400 years earlier than proximate European sites. These results suggest that sophisticated social networks linked the Neolithic front in southern Europe to the Mesolithic peoples of northern Europe.

Le Cambrien basal (Étage Fortunien, env. 535 Ma) de la Formation de Kuanchuanpu dans la Province chinoise du Shaanxi, contient une grande variété de Small Shelly Fossils (SSF) préservés grâce à une phosphatisation secondaire. On y trouve les éléments exosquelettiques de groups animaux très variés mais également des embryons et stades larvaires conservés en trois dimensions et interprétés par les auteurs précédents comme de possible cnidaires. Cette faune dans son ensemble est une source d’informations exceptionnelle sur les toutes premières étapes de la diversification animal avant qu’elle n’atteigne son plein développement (ex : au cours du Cambrien inférieur, Série 2, Étage 3). Nous avons exploré ici la morphologie de ces organismes fossiles submillimétriques au moyen de la Microscopie Électronique à Balayage (SEM) et de techniques microtomographiques aux rayons X (Computed X-ray Microtomography, XTM et Synchrotron X-ray Microtomography, SRXTM), testé les hypothèses concernant leurs possibles affinités avec les cnidaires et analysé leur possible relations phylogénétiques avec les groups actuels de cnidaires. Parmi ces fossiles, certains (ex : Olivooides et formes apparentées) peuvent être raisonnablement considérées comme des cnidaires sur la base de leur anatomie interne, leur symétrie radiale et leurs caractères externes, et pourraient appartenir au groupes-souche des Scyphozoa, Cubozoa et Anthozoa. Des représentants des groupescouronne Scyphozoa, Cubozoa, Anthozoa et Hydrozoa semblent apparaître plus tard dans l’évolution des cnidaires (pas avant le Cambrien inférieur Série 2, Étage 3) comme l’indiquent les méduses du gisement exceptionnel (Lagerstätte) de Chengjiang (env. 521 Ma) qui ressemblent en tout point aux méduses actuelles et possédaient déjà un système sensorial sophistiqué. Notre étude met en lumière une série de caractères atypiques chez les cnidaires ancestraux de Kuanchuanpu: 1) la coexistence de divers modes de symétrie, 2) la prédominance de la symétrie pentaradiale, 3) l’existence d’un mode de développement direct (apparemment sans larve planula) contrastant ainsi avec tous les cnidaires actuels et 4) une taille corporelle très petite compatible avec un mode de vie meiobenthique / The lowermost Cambrian (Fortunian Stage; ca. 535 Ma) Kuanchuanpu Formation from China contains a great variety of secondarily phosphatized Small Shelly Fossils such as exoskeletal elements of various animal groups but also yields three-dimension allypreserved embryos and larval stages interpreted as cnidarians by previous authors. This biota is an exceptional source of information on the early steps of animal biodiversification before its full development (e.g. early Cambrian, Series 2, Stage 3).We explored the morphology of these sub-millimetric fossil organisms by means of Scanning Electron Microscopy (SEM), Computed X-ray Microtomography (XTM) and Synchrotron X-ray Microtomography (SRXTM), and tested their cnidarian affinities and analyzed their possible relation to modern cnidarian groups. Some of them (e.g.Olivooides and related forms) can be reasonably considered as cnidarians based on their internal anatomy, radial symmetry and external features, and may belong to the stem groups Scyphozoa, Cubozoa and Anthozoa. Crown-group scyphozoans,cubozoans, anthozoans and hydrozoans seem to appear later in the evolution of cnidarians, not before Stage 3, Series 2 of the early Cambrian as indicated by the jellyfish from the Chengjiang Lagerstätte (ca. 521 Ma) which closely resemble modern tetraradial medusae and possessed sophisticated sensory organs. Our study highlights some important “atypical” features of the ancestral cnidarians from the Kuanchuanpubiota such as 1) the co-existence of diverse symmetry patterns, 2) the prevalence of pentaradial symmetry, 3) a possible direct development (with no planula larva) contrasting with all modern cnidarians and 4) a small body size consistent with ameiobenthic lifestyle

The morphological diversity of the external and internal surfaces of the petrosal bone, which contains the structures of the inner ear, across a broad range of therian mammals is documented, and patterns of variation across taxa are identified. One pattern of variation is the result of ontogenetic changes in the ear region, as described for the external surface morphology of a sample of isolated petrosal bones referred to Proboscidea from Pleistocene deposits in central Texas. The morphology of the aquaeductus Fallopii for passage of the greater petrosal branch of the facial nerve supports an ontogenetic explanation for some variation within the proboscidean sample, and a sequence of ossification surrounding the aquaeductus Fallopii is hypothesized. Further ontogenetic patterns are investigated using digital endocasts of the bony labyrinth (preserved on the internal surfaces of the petrosal) constructed from CT data across a growth series of the opossum Monodelphis domestica. Strong correlation between skull length and age is found, but from 27 days after birth onward, there is no correlation with age among most dimensions of the inner ear. Adult dimensions of several of the inner ear structures are achieved before the inner ear is functional in M. domestica. Morphological variation within the inner ear of several eutherian mammals from the Cretaceous of Asia, including zhelestids from the Bissekty Formation of Uzbekistan, is described. The variation within the fossil sample is compared to that observed within extant species of placental mammals, and it is determined that the amount of variation within the Bissekty zhelestid population is within the range of that measured for extant species. Additional evolutionary and physiological patterns preserved within the walls of the bony labyrinth are identified through a high level anatomical comparison of the inner ear cavities across Placentalia as a whole. In particular, features of the inner ear support monophyly of Cetacea, Carnivora, Primatomorpha, and caviomorph Rodentia. The volumetric percentage of the vestibular apparatus (vestibule plus semicircular canals) of aquatic mammals is smaller than that calculated for terrestrial relatives of comparable body size. Thus, aspects of the bony labyrinth are both phylogenetically and physiologically informative. / text

Der er ingen undoing i bioheden, der sker bare noget nyt. Går noget under, kommer noget nyt frem af det gamle. Vi har glemt at vi selv har gået under mange gange. Vi bygger huse ovenpå glemte samfund, som Mexico Citys opbyggelse af de gamle atzekertempler. Vi bygger alting oven på hinanden, lag på lag på lag, og det nye gemmer det gamle. Men under os ligger der stadig spor fra det der er født og forgået før os. Arkæologer og palæontologer graver brudstykker frem og vi er fastlåst i vores forestillinger. Er det først gravet op, kan vi ikke lægge det tilbage. Vi kan bare lede efter mere. Indtil vi finder ruinerne af os selv. Bioheden varer ved.

O presente trabalho visa analisar, a partir da perspectiva do uso final de energia, os resultados do indicador de eficiência criado para averiguar o desempenho de equipamentos usados em obras de construção civil de grande porte. Dentro do setor apreciado, optou-se por analisar energeticamente apenas a fase de construção per si em razão desta etapa ser uma fase de intenso consumo energético. O presente trabalho contou com uma compilação de dados baseados no consumo de 26.121 equipamentos em operação, em 84 obras de construção de grande porte. A partir do banco de dados inicial realizou-se a análise dos dados dos equipamentos monitorados via satélite e com informações de eficiência. Por fim, estimou-se, especificamente, a variação da eficiência nos equipamentos em questão. Na busca de resultados, foi possível constatar uma predominância no consumo de óleo diesel quando comparado a outros insumos energéticos. Geradores, guindastes, compressores e caminhões foram os itens que apresentaram maiores índices de eficiência, com 99,0%, 93,5%, 93,2% e 92,3%, respectivamente. Esses resultados mostram que a maior parte destes equipamentos operam próximo ao ótimo do consumo por hora registrado no projeto. / The present work aims to analyze, from the perspective of the end use of energy, the results of the efficiency indicator created in order to investigate the performance of a group of equipment widely used in large construction projects in Brazil. The analyze comprehends only construction period itself due this step is to consider a phase of intense energy consumption. This work included a database related to the fuel consumption of 26,121 equipment during their operation, at 84 work sites in the large construction projects. From the database described, we performed data analysis of satellite equipment monitored and with efficiency information. Finally, it was estimated the variation of efficiency of the equipment in question. The results show a predominance of diesel consumption when compared to other fuels inputs. Considering our methodology, generators, cranes, compressors and trucks were the items that had higher levels of efficiency, with 99.0%, 93.5%, 93.2% and 92.3%, respectively. These results show that most of these devices operate close to the optimal consumption per hour recorded in the project.

A detailed study was made of the composition and distribution of modern and fossil animal and plant traces around saline, alkaline lakes in tectonically active, closed lake-basins. Modern and Pleistocene traces that were examined in lake basins of the Kenya Rift Valley (Lakes Bogoria, Magadi, and Nasikie Engida) were compared directly with fossil traces from the Eocene Lake Gosiute in the Green River Formation of Wyoming, U.S.A., which had a similar hydrochemistry. Analysis of lithofacies and the stratigraphic packaging of the sediments hosting biogenic structures was undertaken so that their vertical and lateral distribution could be used to interpret lake histories and to help to develop depositional models of enigmatic sedimentary successions. A focus was given to the application of the results for paleoecology and stratigraphy, and a model for predicting the position of different trace associations in vertical successions and in different parts of saline, alkaline lake basins has been developed. Evidence from the Kenyan lakes and Eocene Lake Gosiute shows that (1) sedimentary environments are diverse in underfilled basins, and frequent lake-level fluctuations strongly impact the distribution of sedimentary environments suitable for the production and preservation of biogenic structures; (2) the distribution of biogenic structures in underfilled basins is related to the geomorphological and structural setting, tectonic activity, catchment lithology, the basin margin or basin centre location, climate, and salinity and alkalinity, together with other finer-scale environmental and biological controls; (3) because saline environments are restrictive, sites of relatively dilute inflow (springs, rivers and deltas, ephemeral streams) provide oasis-like habitats for animals and plants, and contribute to the increased diversity and laterally variable distribution of saline-lake trace assemblages; and (4) the vertical distribution of trace fossils in a stratigraphic succession reflects changing environments through time; important stratigraphic surfaces, usually formed during periods of lake-level fall, can be recognized from the overprinting patterns of traces produced under different conditions.

A detailed study was made of the composition and distribution of modern and fossil animal and plant traces around saline, alkaline lakes in tectonically active, closed lake-basins. Modern and Pleistocene traces that were examined in lake basins of the Kenya Rift Valley (Lakes Bogoria, Magadi, and Nasikie Engida) were compared directly with fossil traces from the Eocene Lake Gosiute in the Green River Formation of Wyoming, U.S.A., which had a similar hydrochemistry. Analysis of lithofacies and the stratigraphic packaging of the sediments hosting biogenic structures was undertaken so that their vertical and lateral distribution could be used to interpret lake histories and to help to develop depositional models of enigmatic sedimentary successions. A focus was given to the application of the results for paleoecology and stratigraphy, and a model for predicting the position of different trace associations in vertical successions and in different parts of saline, alkaline lake basins has been developed. Evidence from the Kenyan lakes and Eocene Lake Gosiute shows that (1) sedimentary environments are diverse in underfilled basins, and frequent lake-level fluctuations strongly impact the distribution of sedimentary environments suitable for the production and preservation of biogenic structures; (2) the distribution of biogenic structures in underfilled basins is related to the geomorphological and structural setting, tectonic activity, catchment lithology, the basin margin or basin centre location, climate, and salinity and alkalinity, together with other finer-scale environmental and biological controls; (3) because saline environments are restrictive, sites of relatively dilute inflow (springs, rivers and deltas, ephemeral streams) provide oasis-like habitats for animals and plants, and contribute to the increased diversity and laterally variable distribution of saline-lake trace assemblages; and (4) the vertical distribution of trace fossils in a stratigraphic succession reflects changing environments through time; important stratigraphic surfaces, usually formed during periods of lake-level fall, can be recognized from the overprinting patterns of traces produced under different conditions.