Geological controls on regional transmissivity anisotropy

A variety of data indicate that the Carbonate aquifer in southern Manitoba is a heterogeneous and anisotropic aquifer wherein groundwater flow follows preferred flow path networks. Specific capacity tests show that aquifer transmissivity can vary by up to four orders of magnitude within 1 km. Geostatistical analysis reveals a strong anisotropy in the transmissivity field, with better spatial continuity in NE–SW and NW–SE directions, coincident with the dominant orientations of fractures observed in bedrock exposures. However, discrepancies between the orientation of highest fracture density and best transmissivity continuity suggest that either additional geological factors control the preferred flow network or there is a biased representation of the fracture pattern because all direct fracture observations came from the northern part of the study area. In an effort to investigate whether the geographically biased fracture data set represents the fracture pattern for the whole region, Landsat images and digital elevation maps were processed to extract linear features that may indicate subsurface fracture zones in areas where bedrock is covered by glacial sediments. The results suggest a consistent fracture pattern throughout the study area, indicating that the two observed fracture groups might have gone through different processes in terms of permeability development. Alteration by mineral cementation and dissolution along fracture surfaces may have preferentially improved the fracture permeability in one orientation, while reducing it in the other. The in situ stress field is also believed to play a major role in the preferred regional flow network. This paper discusses the evidence for the preferred flow path network and possible geological factors controlling aquifer anisotropy in this region.     

Virtual zooarchaeology: building a web-based reference collection of northern vertebrates for archaeofaunal research and education

Osteological reference collections are a crucial tool in archaeofaunal analysis, but few are comprehensive; most lack a broad range of taxa or multiple individuals per taxon. This problem is especially prominent in arctic zooarchaeology, where difficulty in obtaining, transporting, and processing northern taxa has led to a dearth of appropriate reference collections. The Virtual Zooarchaeology of the Arctic Project, or VZAP, seeks to develop a comprehensive virtual comparative assemblage for the skeletons of northern vertebrates. VZAP (http://vzap.iri.isu.edu) is designed to assist with identifications in the lab or field and provides significant educational value, for both classroom demonstration and personal consultation. The VZAP website presents high-resolution digital photographs and 3D models of skeletal elements via an intuitive graphical user interface, designed to mimic the visual experience of working with a real comparative collection. This custom-built interface, the Dynamic Image Engine, represents a new way to present heritage media in an interactive and engaging format. VZAP also implements unique 3D scanning protocols to increase the realism of 3D models, and delivers them on a platform that allows for point to point measurements, cross-sections, morphological labels, and anatomical orientations.     

Ancient DNA in human bones from Neolithic and Bronze Age sites in Greece and Crete

Attempts were made to detect ancient DNA (aDNA) in samples of 88 human skeletons from eight Neolithic and Bronze Age sites in Greece and Crete. Ancient DNA was absent in specimens from Nea Nikomedia, Lerna, Karaviádena (Zakro), Antron Grave Circle A and Mycenae Grave Circle A. For each of three skeletons from Antron Grave Circle B that were sampled, polymerase chain reactions (PCRs) gave products for nuclear but not mitochondrial DNA, but amplicon yield was low and inconsistent with replicate PCRs failing to give reproducible results. With specimens from Mycenae Grave Circle B, evidence for mitochondrial aDNA was obtained for four of the 22 skeletons that were studied, and at Kouphovouno evidence for mitochondrial and/or nuclear aDNA was obtained with eight of the 20 skeletons that were examined. We conclude that, although aDNA might be present in some Eastern Mediterranean skeletons from later centuries of the Bronze Age, it is not commonly found in material from this period and is likely to be absent from older material.