PHYSIOGRAPHY,FORAMINIFERA AND SEDIMENTATION IN THE Dovey Estuary (Wales)

A study of the chemistry, circulation and sedimentation is followed by an outline account of the living and dead communities (particularly foraminifera) characteristic of the main physiographic subenvironments. On the basis of the relationships established these results are used in an interpretation of the vertical sequence.     

Subdividing the Holocene Series/Epoch: formalization of stages/ages and subseries/subepochs,and designation of GSSPs and auxiliary stratotypes

The Holocene, which currently spans ~11 700 years, is the shortest series/epoch within the geological time scale (GTS), yet it contains a rich archive of evidence in stratigraphical contexts that are frequently continuous and often preserved at high levels of resolution. On 14 June 2018, the Executive Committee of the International Union of Geological Sciences formally ratified a proposal to subdivide the Holocene into three stages/ages, along with their equivalent subseries/subepochs, each anchored by a Global boundary Stratotype Section and Point (GSSP). The new stages are the Greenlandian (Lower/Early Holocene Subseries/Subepoch) with its GSSP in the Greenland NGRIP2 ice core and dated at 11 700 a b2k (before 2000 CE); the Northgrippian (Middle Holocene Subseries/Subepoch) with its GSSP in the Greenland NGRIP1 ice core and dated at 8236 a b2k; and the Meghalayan (Upper/Late Holocene Subseries/Subepoch) with its GSSP in a speleothem from Mawmluh Cave, north‐eastern India, with a date of 4250 a b2k. We explain the nomenclature of the new divisions, describe the procedures involved in the ratification process, designate auxiliary stratotypes to support the GSSPs and consider the implications of the subdivision for defining the Anthropocene as a new unit within the GTS.     

The influence of orbital parameters on the North American Monsoon system during the Last Interglacial Period

The response of summer precipitation in the western United States to climate variability remains a subject of uncertainty. For example, palaeoclimate records indicate the North American Monsoon (NAM) was stronger and spatially more extensive during the Holocene, whereas recent modelling suggests a weakened NAM response to increasing temperatures. These illustrate diverging pictures of the NAM response to warming. Here, we examine summer precipitation in the southwestern US related to Last Interglacial insolation forcing. Using a high-resolution climate model, we find that Eemian insolation forcing results in overall wetter conditions throughout most of the southwestern US, but significantly drier than present conditions over Arizona. The overall wetter conditions are associated with a northward shift of the anticyclonic circulation aloft and increased moisture in the lower and mid-troposphere during the Eemian. Increased advection of Gulf of Mexico moisture is responsible for increasing precipitation in New Mexico and the northern edges of the NAM region. Drier conditions over Arizona are likely related to reduced local convection associated with reduced vertical moisture transport. These results highlight the spatial complexity of the NAM response to increasing radiative forcing and allow a better understanding of monsoon dynamics and variability in response to a warming climate.     

Geochemistry and origins of the annagh division of the precambrian erris complex,N.W. county Mayo,Ireland

A geochemical study of 29 acid gneisses from the Annagh Division of the Erris Complex has shown that all lithologies are chemically distinct and that further distinction can be made between different areas. The acid and intermediate gneisses, which in the field have been regarded as orthogneisses associated with widespread metasomatism, have orthogneiss chemistry and show the effects of considerable local metasomatism. Isotopic age dating records that the latest major pre-Caledonian event in the Annagh Gneiss is of Grenvillian age. The Annagh Division gneiss differs chemically from Laxford gneiss but is similar to reworked Lewisian inliers seen in the N.W. Highlands of Scotland.All analysed basic rocks fall into three categories: early basic and ultrabasic pods and metadolerite dykes. All originated as minor intrusives of tholeiitic affinities.     

Choosing the Right Policy Tools to Encourage Watershed Stewardship through the Study of Attitude

Recently, a number of “Payment for Watershed Services” programs have aimed to engage private landowners in watershed stewardship initiatives by offering financial incentives for adopting watershed best management practices. However, a growing field of research suggests that financial incentives alone may be of limited utility to encourage widespread and long-standing behavior change, and other policy tools may be required. This research examines how attitudes may influence enrollment in watershed stewardship programs to shed light the application of incentive, capacity building, and symbolic policy tools. We distributed a questionnaire to rural landowners in the Clackamas River watershed, OR, and received 281 valid responses (29% response rate). We found that attitudes associated with trust, ecological understanding, and technical capacity played more fundamental roles compared with financial considerations. We interpret these findings by evaluating the likely efficacy of various policy tools, and stress the importance of engaging landowners by building capacity and trust.     

On counting the number of data pairs for semivariogram estimation

In planning spatial sampling studies for the purpose of estimating the semivariogram, the number of data pairs separated by a given distance is sometimes used as a comparative index of the precision which can be expected from a given sampling design. Because spatial data are correlated, this index can be unreliable. An alternative index which partially corrects for this correlation, themaximum equivalent uncorrelated pairs, is proposed for comparing spatial designs. The index is developed under the assumption that the underlying stochastic process is Gaussian and is appropriate when the (population) semivariogram is to be estimated by the sample semivariogram.     

Zur Approximation von Laufzeitfunktionen aus diskreten Messwerten mit abgebrochenen Potenzreihen

Zusammenfassung Es wird eine Approximation von Laufzeitfunktionen aus diskreten Messwerten mit abgebrochenen Potenzreihen behandelt. Zur bequemen Anwendung werden Tabellen berechnet. Der Beitrag schliesst mit einem Beispiel aus der Praxis.

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Summary An approximation to travel-time functions by restriced power series is treated. For numerical computations convenient tables are calculated and an example is given.

     

III. Bücher- und Zeitschriftenschau

Ohne Zusammenfassung