Oxygen isotopic composition of mammalian skeletal phosphate from the Natufian Period,Hayonim Cave,Israel: Diagenesis and paleoclimate

Recent and fossil (prehistoric, Natufian) gazelle bones, dentin and enamel were analyzed for their oxygen isotopic composition (δ¹⁸O) of the phosphate and carbonate, as well as their crystallinity. Fossil bones and dentin have better crystallinity than recent specimens, indicating diagenetic change. Fossil enamel, on the other hand, is identical in crystallinity to recent enamel, indicating the lack of diagenetic alteration. Comparison of δ¹⁸O of carbonate and phosphate of the skeletal elements suggests that the coexisting phosphate and carbonate of both the recent and fossil specimens are close to isotopic equilibrium. This might suggest that both phases were affected by the same degree of diagenetic alteration, and that comparison of their δ¹⁸O is not useful for the selection of pristine material for paleoclimatic reconstruction purposes. Oxygen isotope analysis of gazelle enamel from the Natufian period from Hayonim Cave, Israel, show depletion in δ¹⁸O in comparison with recent enamel. This depletion is interpreted to represent a colder and/or wetter climate in the Natufian of northern Israel. © 1999 John Wiley & Sons, Inc.     

A sample preparation guide for clay-rich carbonaceous chondrites

The matrix of the C2-ungrouped Tarda meteorite contains abundant smectite minerals that swell and crumble when exposed to polar liquids, causing the sample to rapidly slake. This phenomenon presents a serious challenge when polishing the meteorite, as common polishing liquids used on carbonaceous chondrites, such as water, ethanol, ethylene glycol, and isopropyl alcohol, are polar and will cause the sample to swell, making it unsuitable for some analyses. Hexane and mineral oil are nonpolar liquids that were found to not induce swelling on highly expansive montmorillonite-clay analog material and were effectively integrated into a polishing procedure for Tarda. Here, we detail a procedure for mounting, cutting, and polishing the Tarda meteorite to prepare a surface that is suitable for a variety of sensitive techniques, such as electron microprobe analysis. This work offers a practical methodology for the preparation of other clay-rich samples, which may include the recently returned Ryugu and Bennu materials.     

Statistical algorithms accounting for background density in the detection of UXO target areas at DoD munitions sites

Statistically defensible methods are presented for developing geophysical detector sampling plans and analyzing data for munitions response sites where unexploded ordnance (UXO) may exist. Detection methods for identifying areas of elevated anomaly density from background density are shown. Additionally, methods are described which aid in the choice of transect pattern and spacing to assure with degree of confidence that a target area (TA) of specific size, shape, and anomaly density will be identified using the detection methods. Methods for evaluating the sensitivity of designs to variation in certain parameters are also discussed. Methods presented have been incorporated into the Visual Sample Plan (VSP) software (free at ) and demonstrated at multiple sites in the United States. Application examples from actual transect designs and surveys from the previous two years are demonstrated.     

Beyond 'someone else's agenda': An example of indigenous/academic research collaboration

In recent years, Māori and wider indigenous geographies have flourished. These include works by scholars identifying specific Māori or indigenous issues but less attention has been paid to the way such research is conducted. This paper engages with these developments and presents the practices and lessons learnt from one particular research collaboration. Relationship building, multiple methods, flexibility, communication choices and wider support are all noted as key elements in establishing a supportive and fruitful collaboration.     

Variation between bee communities on a sand dune complex in the Great Basin Desert,North America: Implications for sand dune conservation

Sand dunes across the Mojave and Great Basin Deserts house rich bee communities. The pollination services these bees provide can be vital in maintaining the diverse, and often endemic, dune flora. These dune environments, however, are threatened by intense off-highway vehicle (OHV) use. Conservation efforts adopted by land managers often consist of setting aside a portion of a dune system that is off-limits to OHV use, but little work has been done showing the extent to which this protects native bee communities. A two-year study of bee communities on a Great Basin sand dune complex in Dugway Proving Ground located in northwestern Utah revealed low similarity index values between closely situated collecting plots (1–40 km apart). Similarity values ranged from 0.13 to 0.70 for species composition, and from 0.07 to 0.57 when similarity was weighted by abundance. Distance between plots had no significant relationship to similarity when richness and abundance were considered. Bee similarity between plots was significantly correlated with floral similarity. These results indicate that dune conservation strategies that preserve “representative” portions of dune systems may be insufficient to protect bees and the pollination services they provide.     

KT3D_H2O: A Program for Kriging Water Level Data Using Hydrologic Drift Terms

It is often necessary to estimate the zone of contribution to, or the capture zone developed by, pumped wells: for example, when evaluating pump-and-treat remedies and when developing wellhead protection areas for supply wells. Tonkin and Larson (2002) and Brochu and Marcotte (2003) describe a mapping-based method for estimating the capture zone of pumped wells, developed by combining universal kriging (kriging with a trend) with analytical expressions that describe the response of the potentiometric surface to certain applied stresses. This Methods Note describes (a) expansions to the techinque described by Tonkin and Larson (2002) ; (b) the concept of the capture frequency map (CFM), a technique that combines information from multiple capture zone maps into a single depiction of capture; (c) the development of a graphical user interface to facilitate the use of the methods described; and (d) the integration of these programs within the MapWindow geographic information system environment. An example application is presented that illustrates ground water level contours, capture zones, and a CFM prepared using the methods and software described.     

Evaluating ecological quality in the north-eastern Black Sea coastal zone

Anthropogenic pressures have resulted in measurable impacts on the coastal ecosystems of the northern (Sevastopol Bay, Ukraine) and eastern (Batumi aquatoria, Georgia) Black Sea. Indices suggest that major impacts are relatively localized and are comparable to similar situations in the northern Atlantic. In contrast, biodiversity was appreciably lower than from comparable north Atlantic waters. The number of macrobenthic species was typically round 50, less than half the number that might be expected from similar exercises in US or European waters. Site-specific indices likewise indicated a somewhat lower diversity within communities, yielding metrics which would indicate a measure of stress in N. Atlantic situations. Microbial status was generally good, although regions close to urbanisation did not comply with standards laid down in the current EC Bathing Water Directive (76/EC/160). Likewise viruses were more commonly, although not exclusively, associated with urban locations, as were phages. Microbial investigation of the sediments confirmed the presence of heterotrophic and oil-oxidising bacteria. Abundance of the latter was closely correlated to the degree of oil contamination of the sediments, and to temperature, although for both, the results showed that the increase in bacterial abundance did level off beyond a certain point. Numbers of oil-oxidising bacteria in the water column displayed a classical response to temperature, with abundance doubling over a 10-degree C rise in temperature. Overall the results suggest that while indices in current use are useful in evaluating coastal quality in the Black Sea, some adjustments would be necessary especially in the establishment of baseline or reference values.     

U–Pb dating of zircon in hydrothermally altered rocks as a correlation tool: Application to the Mangakino geothermal field,New Zealand

Recognition and correlation of rock units within geothermal fields is often hampered by high degrees of alteration that obscure primary mineralogies and lithological boundaries, and preclude direct dating by radiometric techniques. Magmatic zircons are commonly present in silicic volcanic rocks, where zircon saturation was achieved and zircons crystallized up to the point of eruption. Young zircons are highly resistant to hydrothermal alteration and can yield a record of their crystallization ages in otherwise heavily altered rocks. Zircon crystallization-age spectra have been obtained by SIMS techniques (SHRIMP-RG) from three samples of cuttings and a core sample from ignimbrite penetrated in 3 drillholes up to ~ 3.2 km deep at the Mangakino geothermal field in New Zealand. The crystallization ages are similar between the drillcore and cutting samples, indicating that downhole mixing of cuttings has not been important, and showing collectively that volcanic units of closely similar ages are represented between ~ 1.4 and ~ 3.2 km depth. This is despite apparent changes in the inferred primary volcanic lithology that had led to earlier inferences that multiple ignimbrites of contrasting age were present in this depth interval. Comparisons of zircon crystallization-age spectra and inferred primary mineralogical characteristics from the drillhole samples with surficial ignimbrites that crop out west of Mangakino suggest that the boreholes have entered a > 1.8-km-thick intracaldera fill of ignimbrite generated in the closely-spaced Kidnappers and Rocky Hill eruptions at ~ 1 Ma.