Paleosols and prehistoric populations in the high plains

Excavations in 1980–1981 at sites (32MZ319 and 32MZ380) along Cinnamon Creek Ridge in the Little Missouri River Badlands of McKenzie County, North Dakota, unexpectedly revealed at each locality the presence of one or more deeply buried paleosols with associated cultural materials. At both sites, 32MZ319 and 32MZ380, multiple paleosols are present, each of which is terminated by an episode of aeolian deposition. Fifteen radiocarbon dates on these paleosols establish an incipient chronology for paleosol development in the study area and permit correlation with other High Plains archaeological complexes. Geological and archaeological data for the two multiple paleosol sites are summarized.     

Investigating Bermuda's pollution history through stable isotope analyses of modern and museum-held gorgonian corals

For centuries, Bermuda has been challenged with wastewater management for the protection of human and environmental health. By quantifying the δ¹⁵N of the common sea fan Gorgonia ventalina sampled from 30 sites throughout Bermuda we show that sewage-derived nitrogen is detectable on nearshore coral reefs and declines across the lagoon to the outer rim. We also sampled gorgonians from two museum collections representing a 50y time-series (1958–2008). These samples revealed an increase in δ¹⁵N of > 4.0‰ until the mid-1970s, after which δ¹⁵N values slowly declined by ~ 2.0‰. A δ¹⁵N chronology from a gorgonian skeleton exhibited a similar decline over the last 30–40 years of approximately 0.6‰. We conclude that policies have been effective in reducing sewage impacts to Bermudian reefs. However, significant sources of sewage pollution persist and are likely have a strong impact on harbor and nearshore coral communities and human health.     

A very large scale GIS-based groundwater flow model for the Nubian sandstone aquifer in Eastern Sahara (Egypt,northern Sudan and eastern Libya)

A three-dimensional GIS-based groundwater flow model for the Nubian Sandstone Aquifer in the eastern Sahara was developed and calibrated under steady-state and transient conditions. The model was used to simulate the response of the aquifer to climatic changes that occurred during the last 25,000 years. The simulation results indicated that the groundwater in this aquifer was formed by infiltration during the wet periods 20,000 and 5,000 years b.p. The recharge of groundwater due to regional groundwater flow from more humid areas in the south was excluded. It also indicates that the Nubian Aquifer System is a fossil aquifer, which had been in an unsteady state condition for the last 3,000 years.

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Resumen Fue desarrollado un modelo de flujo de agua subterránea en tres dimensiones, basado en un SIG, para el Acuífero Arenisca Nubian en el Sahara Oriental, el cual fue calibrado para condiciones de estado estacionario y transitorio. El modelo se usó para simular la respuesta del acuífero a los cambios climáticos que ocurrieron durante los últimos 25000 años. Los resultados de esta simulación indicaron que el agua subterránea en este acuífero, se formó por infiltración, durante los períodos húmedos que hubo hace 20000 y 5000 años, antes del presente. Fue excluida la recarga del acuífero debida a un flujo regional de agua subterránea proveniente de áreas con un clima más húmedo en el sur. El modelo también muestra, que el Sistema Acuífero Nubian es un acuífero fósil, el cual ha permanecido en una condición de estado no estacionario, durante los últimos tres mil años.

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Résumé Pour laquifère gréseux Nubien de Sahara -Est on a mis au points un modèle tridimensionnel, basé sur GIS. Le modèle a été calibré tant pour lécoulement stationnaire que pour lécoulement transitoire. On a simulé après la réponse de laquifère aux changements climatiques des derniers 25000 ans. Les résultats des simulations indiquent que la nappe a été rechargée par des infiltrations pendant une période humide qui sétend 5000 et 20000 ans, dès temps actuel. On na pas pris en compte la recharge de laquifère par la zone plus humide située dans sa partie sud. Le modèle indique aussi que leau de laquifère Nubien est une eau fossile qui a eu un écoulement transitoire pendant les derniers 3000 ans.

     

Selenium in a shore bird,the dunlin,from the Dutch Waddenzee

The hypothesis that Se is secreted by birds via the preen gland or salt glands, thus contaminating the feathers, has been investigated. It is concluded that the feather vanes show indirectly in this way the birds' e?posure to Se. Therefore they can be used as an indicator tissue for this element.     

A geologist’s shining path

Chronicle

A geologist’s shining path