The bulk mineralogy,elemental composition,and water content of the Winchcombe CM chondrite fall

On the microscale, the Winchcombe CM carbonaceous chondrite contains a number of lithological units with a variety of degrees of aqueous alteration. However, an understanding of the average hydration state is useful when comparing to other meteorites and remote observations of airless bodies. We report correlated bulk analyses on multiple subsamples of the Winchcombe meteorite, determining an average phyllosilicate fraction petrologic type of 1.2 and an average water content of 11.9 wt%. We show the elemental composition and distribution of iron and iron oxidation state are consistent with measurements from other CM chondrites; however, Winchcombe shows a low Hg concentration of 58.1 ± 0.5 ng g⁻¹. We demonstrate that infrared reflectance spectra of Winchcombe are consistent with its bulk modal mineralogy, and comparable to other CM chondrites with similar average petrologic types. Finally, we also evaluate whether spectral parameters can estimate H/Si ratios and water abundances, finding generally spectral parameters underestimate water abundance compared to measured values.     

Inverted clast stratigraphy in an eolian archaeological environment

Understanding the geomorphic history of eolian basins is important in interpreting the archaeological record and human responses to past environments. One hundred forty soil profiles were excavated and described in southern New Mexico and West Texas. Seven major late Quaternary stratigraphic units were found: La Mesa, eolian Jornada (I, II), eolian Isaacks' Ranch, eolian Organ (I, II, and III), Historical Blowsand, and the playa deposits of Petts Tank and Lake Tank. Each unit represents a period of landscape instability, eolian erosion, and concurrent deposition, followed by landscape stability and soil formation. Eolian erosion can form local surficial lag deposits if materials larger than the competence of the wind are present. However, erosional processes alone cannot explain the presence of older clasts at the surface with intact, younger deposits underneath. We propose a combination of processes: deflation in eolian windows, followed by lateral movement of clasts over areas that have not been deflated. The effects of these processes on artifact stratigraphy and archaeological interpretations could be significant. © 2002 Wiley Periodicals, Inc.     

Influence of leaf and canopy characteristics on rainfall interception and urban hydrology

Considering the rapid expansion of urban populations and the corresponding urbanization of landscapes, a dearth of knowledge exists regarding the role of urban vegetation in modulating urban ecosystem functioning. In response to the need for the development of new approaches to quantify ecohydrological processes along urban-to-rural gradients at alternate scales, this study explores the relationship between individual plant selection choices in landscaping and changes in urban hydrological functioning. This research examines differences in the variation of rainfall interception, leaf hydrophobicity, canopy structure, and water storage, between 13 species in an urban, semi-arid location. The species studied were selected based on resident preferences, and hence this research considers the role that urban residents play, through individual choices, in modifying the ecohydrology of an urban watershed. Rainfall interception, canopy surface storage, leaf hydrophobicity, and water droplet retention were significantly different between species. Results indicate that individual choice in plant selection for landscaping may influence urban hydrology.     

Data‐Driven Approach for Analyzing Hydrogeology and Groundwater Quality Across Multiple Scales

Recent trends of assimilating water well records into statewide databases provide a new opportunity for evaluating spatial dynamics of groundwater quality and quantity. However, these datasets are scarcely rigorously analyzed to address larger scientific problems because they are of lower quality and massive. We develop an approach for utilizing well databases to analyze physical and geochemical aspects of groundwater systems, and apply it to a multiscale investigation of the sources and dynamics of chloride (Cl^?) in the near‐surface groundwater of the Lower Peninsula of Michigan. Nearly 500,000 static water levels (SWLs) were critically evaluated, extracted, and analyzed to delineate long‐term, average groundwater flow patterns using a nonstationary kriging technique at the basin‐scale (i.e., across the entire peninsula). Two regions identified as major basin‐scale discharge zones—the Michigan and Saginaw Lowlands—were further analyzed with regional‐ and local‐scale SWL models. Groundwater valleys (“discharge” zones) and mounds (“recharge” zones) were identified for all models, and the proportions of wells with elevated Cl^? concentrations in each zone were calculated, visualized, and compared. Concentrations in discharge zones, where groundwater is expected to flow primarily upwards, are consistently and significantly higher than those in recharge zones. A synoptic sampling campaign in the Michigan Lowlands revealed concentrations generally increase with depth, a trend noted in previous studies of the Saginaw Lowlands. These strong, consistent SWL and Cl^? distribution patterns across multiple scales suggest that a deep source (i.e., Michigan brines) is the primary cause for the elevated chloride concentrations observed in discharge areas across the peninsula.     

Exploring Landcare Effectiveness Using Organisational Theory

Landcare is an important example of the potential of state-sponsored participation to establish viable local organisations and contribute to rural development. In this paper, the authors discuss their research using organisational theory to explore Landcare effectiveness. Data were obtained from a mailed survey to Landcare groups in the state of Victoria during 1998. Levels of group activity were used as a surrogate measure of group effectiveness. Groups were ranked according to their level of activity to assess the impact of factors likely to affect group performance, the efficacy of program logic, and the extent groups were contributing to program goals. Survey data suggested key aspects of Landcare Program logic were sound. Examination of the membership and activity profiles of groups suggested 90 per cent of the respondent groups were making a worthwhile contribution to program goals. This research also confirmed the importance of factors identified by others as significant influences on organisational effectiveness: the importance of having clear goals, objectives and plans; resource availability; facilitation by an outside agency; access to a funded group co-ordinator; and communication between stakeholders. Unfortunately, there are critical, ongoing management issues surrounding many of these topics.     

Discovery of cryptotephra at Middle–Upper Paleolithic sites Arma Veirana and Riparo Bombrini,Italy: a new link for broader geographic correlations

Chemical characterization of cryptotephra is critical for temporally linking archaeological sites. Here, we describe cryptotephra investigations of two Middle–Upper Paleolithic sites from north-west Italy, Arma Veirana and Riparo Bombrini. Cryptotephra are present as small (<100 µm) rhyolitic glass shards at both sites, with geochemical signatures rare for volcanoes in the Mediterranean region. Two chemically distinct shard populations are present at Arma Veirana (P1 and P2). P1 is a high silica rhyolite (>75 wt.%) with low FeO (<1 wt.%) and a K₂O/Na₂O > 1 and P2 is also a high silica rhyolite (>75 wt.%) but with higher FeO (2.33–2.65 wt.%). Shards at Riparo Bombrini (P3) are of the same composition as P1 shards at Arma Veirana, providing a distinct link between deposits at both sites. Geochemical characteristics suggest three possible sources for P1 and P3: eruptions from Lipari Island (56–37.7 ka) in Italy, the Acigöl volcanic field (200–20 ka) in Turkey and the Miocene Kirka-Phrigian caldera (18 Ma) in Turkey. Eruptions from Lipari Island are the most likely source for P1,3 cryptotephra. This study highlights how cryptotephra can benefit archaeology, by providing a direct link between Arma Veirana and Riparo Bombrini as well as other deposits throughout the Mediterranean.     

A shallow subsurface controlled release facility in Bozeman, Montana, USA, for testing near surface CO2 detection techniques and transport models

A controlled field pilot has been developed in Bozeman, Montana, USA, to study near surface CO₂ transport and detection technologies. A slotted horizontal well divided into six zones was installed in the shallow subsurface. The scale and CO₂ release rates were chosen to be relevant to developing monitoring strategies for geological carbon storage. The field site was characterized before injection, and CO₂ transport and concentrations in saturated soil and the vadose zone were modeled. Controlled releases of CO₂ from the horizontal well were performed in the summers of 2007 and 2008, and collaborators from six national labs, three universities, and the U.S. Geological Survey investigated movement of CO₂ through the soil, water, plants, and air with a wide range of near surface detection techniques. An overview of these results will be presented.     

An evaluation of the use of renewable energy to pump water in Sacala las Lomas,Guatemala

An evaluation has been conducted to establish if using renewable energy is technically and economically feasible to pump water in Sacala las Lomas, Guatemala. A deep groundwater well has been proposed and a multi-stage pump system is being considered to distribute groundwater to users’ homes. A weather station was erected in Sacala to collect site-specific data. Wind velocity, wind direction, solar insolation, temperature, precipitation, and barometric pressure data were collected over a 1-year study period. The analysis of the data indicated that the potential power generated by a photovoltaic array or wind turbine would be insufficient to economically pump water to the village under current conditions. Although there may be reasons other than economics that make the potential renewable energy applications attractive, the space and maintenance required to install and operate a sufficient off-grid system outweigh the benefits. A grid-intertie system would allow any number of solar panels to be used in the system while still providing the electricity demand using grid-power.     

In-Street Wind Direction Variability in the Vicinity of a Busy Intersection in Central London

We present results from fast-response wind measurements within and above a busy intersection between two street canyons (Marylebone Road and Gloucester Place) in Westminster, London taken as part of the DAPPLE (Dispersion of Air Pollution and Penetration into the Local Environment; www.dapple.org.uk ) 2007 field campaign. The data reported here were collected using ultrasonic anemometers on the roof-top of a building adjacent to the intersection and at two heights on a pair of lamp-posts on opposite sides of the intersection. Site characteristics, data analysis and the variation of intersection flow with the above-roof wind direction (θ _ref ) are discussed. Evidence of both flow channelling and recirculation was identified within the canyon, only a few metres from the intersection for along-street and across-street roof-top winds respectively. Results also indicate that for oblique roof-top flows, the intersection flow is a complex combination of bifurcated channelled flows, recirculation and corner vortices. Asymmetries in local building geometry around the intersection and small changes in the background wind direction (changes in 15- min mean θ _ref of 5°–10°) were also observed to have profound influences on the behaviour of intersection flow patterns. Consequently, short time-scale variability in the background flow direction can lead to highly scattered in-street mean flow angles masking the true multi-modal features of the flow and thus further complicating modelling challenges.