Standard Field Techniques Research Articles

Quantifying Downstream, Vertical and Lateral Variation in Fluvial Deposits: Implications From the Huesca Distributive Fluvial System

Quantifying sedimentary deposits is crucial to fully test generic trends cited within facies models. To date, few studies have quantified downstream trends alongside vertical and lateral variations within distributive fluvial systems (DFS), with most studies reporting qualitative trends. This study reports on the generation of a quantitative dataset on the Huesca DFS, Ebro Basin, Spain, in which downstream, vertical and lateral trends in channel characteristics are analyzed using a fusion of field data and virtual outcrop model derived data (VOM). Vertical trend analysis reveals that the exposed portion of the Huesca DFS does not show any systematic changes through time, which suggests autogenic-driven local variability. Proximal-to-distal trends from field data display a downstream decrease in average channel body thicknesses (13.1–0.7 m), channel deposit percentage (70–4%), and average storey thicknesses (5.2–0.7 m) and confirm trends observed on other DFS. The VOM dataset shows a similar downstream trend in all characteristics. The range in values are, however, larger due to the increase in amount of data that can be collected, and trends are thus less clear. This study therefore highlights that standard field techniques do not capture the variability that can be present in outcrops. Channel percentage was found to be most variable (37% variation) in the medial setting, whereas channel body thickness is most variable (∼15 m range) in the proximal setting. Storey thickness varied in both the proximal and medial settings (range of 9 and 11 m for field and VOM data respectively) becoming more consistent downstream. Downstream shifts in architecture are also noted from massive, highly amalgamated channel-body sandstones in proximal regions to isolated or offset-stacked channel-bodies dominating the distal region. Trends are explained by spatial variability in DFS processes and preservation potential. The overlap present indicates that no single value is representative of position within a DFS, which has important implications for interpreting the location that a data point sits within a DFS when using limited (i.e., single log) datasets. These comparative results contribute to improving the accuracy of system-scale downstream predictions for channel characteristic variability within subsurface deposits.

Advances in exploration geochemistry, 2007 to 2017 and beyond

Mineral exploration under relatively young, exotic cover still presents a major challenge to discovery. Advances and future developments can be categorized in four key areas, (1) understanding metal mobility and mechanisms, (2) rapid geochemical analyses, (3) data access, integration and interoperability and (4) innovation in laboratory-based methods. Application of ‘regolith-style' surface mapping in covered terrains outside of conventional lateritic terrains is achieving success in terms of reducing background noise and improving geochemical contrasts. However, process models for anomaly generation are still uncertain and require further research. The interaction between the surface environment, microbes, hydrocarbons and chemistry is receiving greater attention. While significant progress has been achieved in understanding the role of vegetation, interaction with the water table and cycling of metals in the near surface environment in Australia, other regions of the world, for example, the till-covered terrains in the northern hemisphere and arid colluvium-covered areas of South America, have seen less progress. In addition to vegetation, the influence of bacteria, fungi and invertebrates is not as well studied with respect to metal mobilization in cover. Field portable XRF has become a standard field technique, though more often used in a camp setting. Apart from a tweaking of analytical quality, instruments have probably reached their peak of analytical development with add-ons, such as cameras, beam-limiters, wireless transmission and GPS as the main differences between instrument suppliers. Their future rests in automated application in unconventional configurations, for example, core scanning and better integration of analytical data with other information such as spectral analyses. Pattern drilling that persists in industry, however, has benefited from innovative application of field-portable tools along with rock and mineral chemistry to provide near real-time results and assist in a shift toward more flexible and targeted drilling in greenfields settings. Innovation in the laboratory continues to progress. More selective geochemical analysis, imaging of fine particle size fractions and resistate mineral phases and isotope analysis are faster and more accessible than ever before. The application of genomics (and data analysis) as mineral exploration tools is on the horizon. A continuing problem in geoscience, the supply to industry of suitably trained geochemists, persists although some needs, particularly at junior level, will be met by recent initiatives at various universities at graduate level. Unfortunately, the current economic climate has had a significant impact on R&D and retention of geochemistry skills by the industry. Whilst the future is positive, significant investment is required to develop the next generation of geochemical exploration tools and concepts. Thematic collection: This article is part of the Exploration 17 collection available at: https://www.lyellcollection.org/cc/exploration-17

High efficiency protocol of DNA extraction from Micromys minutus mandibles from owl pellets: a tool for molecular research of cryptic mammal species

Owl pellets have high potential as a source of DNA. However, this noninvasive method of collecting DNA is rarely used, and its methodological aspects are poorly understood. We investigated the methodology for DNA extraction and amplification from owl pellets containing the smallest European rodent—the Harvest mouse Micromys minutus—as an example. We used mandibles identified in owl pellets for mitochondrial and nuclear DNA amplification. For DNA extraction, we tested two commercial protocols and utilized a protocol being a combination of two commercial kits which ensured high efficiency of DNA extraction. Additionally, we recorded that the amount of DNA was five times higher in extracts from teeth as compared to DNA extracts from jawbones derived from the same mandible. The quantity of DNA was significantly positively correlated with biological sample weight; however, the age of the pellet remains had an impact on the level of inhibition. We recorded inhibition in 40 % of mtDNA extracts derived from pellets older than 150 months, whereas in DNA extracts from pellets younger than 80 months, we did not observe a negative impact of inhibition on PCR efficiency. The amplification success rate was 89.9 % for the mitochondrial fragment and 39.4 % in the case of the nuclear fragment. We observed partial degradation of DNA evidenced by the fact that the longest fragments that we were able to amplify in the case of mtDNA were 450 and 200 bp for nuDNA. The study shows that pellets can be considered as a source of DNA and have high potential for molecular research in the case of threatened species and species that are difficult to study using standard field techniques.

Detection Dogs: An Effective Technique for Bush Dog Surveys

ABSTRACT Detailed ecological data on the bush dog (Speothos venaticus) have been lacking, since standard field techniques, such as camera traps, have had little success recording their presence. This study eliminates dependence on visitation rate and switches the focus to locating evidence (e.g., olfactory) associated with the species’ natural behavior and movement patterns. Over a 3‐month period, a detection dog located multiple (n = 11, 4 confirmed and 7 potential) bush dog areas in Upper Paraná Atlantic Forest of Misiones Argentina. These positive results demonstrate that detection dogs can provide species‐specific data on the bush dog despite the rugged terrain and dense forest vegetation they may occupy. The ecological data collected using this technique allow effective conservation strategies to be developed, wildlife corridors and biological crossings to be designed, and species distributions to be examined.

Three‐dimensional modelling and sequence stratigraphy of a carbonate ramp‐to‐shelf transition, Permian Upper San Andres Formation

AbstractThis study highlights three‐dimensional variability of stratigraphic geometries in the ramp crest to basin of mixed carbonate–siliciclastic clinoforms in the Permian San Andres Formation. Standard field techniques and mapping using ground‐based lidar reveal a high degree of architectural complexity in channellized, scoured and mounded outer ramp stratigraphy. Development of these features was a function of location along the ramp profile and fluctuations in relative sea‐level. Deposition of coarse‐grained and fine‐grained turbidites in the distal outer ramp occurred through dilute and high‐density turbidity flows and was the result of highstand carbonate shedding within individual cycles. In this setting, high‐frequency cycles of relative sea‐level are interpreted on the basis of turbidite frequency, lateral extent and composition. Submarine siliciclastic sediment bypass during lowstand cycles resulted in variable degrees of siliciclastic preservation. Abundant siliciclastic material is preserved in the basin and distal outer ramp as point‐sourced lowstand wedges and line‐sourced early transgressive blankets. In mounded topography of the outer ramp, siliciclastic preservation is minimal to absent, and rare incised channels offer the best opportunity for recognition of a sequence boundary. Growth of mounded topography in the outer ramp began with scouring, followed by a combination of bioherm construction, fusulinid mound construction and isopachous draping. Intermound areas were then filled with sediment and continued mound growth was prevented by an accommodation limit. Mound growth was independent of high‐frequency cycles in relative sea‐level but was dependent on available accommodation dictated by low‐frequency cyclicity. Low‐angle ramp clinoforms with mounded topography in the outer ramp developed during the transgressive part of a composite sequence. Mound growth terminated as the ramp transformed into a shelf with oblique clinoform geometries during the highstand of the composite sequence. This example represents a ramp‐to‐shelf transition that is the result of forcing by relative sea‐level fluctuations rather than ecologic or tectonic controls.

New data on the status and distribution of the bush dog ( Speothos venaticus): Evaluating its quality of protection and directing research efforts

The bush dog ( Speothos venaticus), listed as CITES Appendix 1 – vulnerable, is a small (5–6 kg), rarely seen canid from Central and South America. The World Conservation Union Canid Specialist Group (IUCN CSG) recommended that research with this species focus on their basic ecology so that a data-driven conservation strategy can be formulated. Information on the bush dog, however, has been lacking since standard field techniques have had little or no success with this species. The S. venaticus Status and Distribution Survey was developed in an attempt to use indirect methodologies to determine the bush dog’s conservation status in the wild, its current distribution, and identify ecological needs by correlating habitat types to bush dog sightings. Survey responses and literature generated a database with 399 historic bush dog locations recorded between 1834 and 2004. These locational records were used to update the species’ range extent map, an important conservation planning tool. With year and precision of data accounted for, we analyzed land use coverage at known locations where bush dogs have historically been reported to evaluate the likelihood that the species persists in the area today. In addition, these locations provided training data for generation of potential distribution maps (i.e., areas of occupancy) using ecological niche modeling (i.e., Maximum Entropy) and bioclimatic data. These analyses revealed that 20% of the historic bush dog locations are associated with fragmented or altered habitat. These results allowed the status of bush dog habitat to be re-evaluated and areas that require more intensive research and protection to be identified.

Modeling TPH Desorption in Unconsolidated Dune Sand during Remediation Using Dual-Equilibrium Desorption (DED) Model

Abstract The verification of the cleanup of dune sands from a dissolved phase petroleum hydrocarbon plume at an active service station site undergoing ozone treatment is being accomplished through soil and groundwater sampling. We hope to use modeling by the dual-equilibrium desorption (DED) model in order to determine when remedial goals negotiated with the regulatory agencies have been met. The site is located in the harbor area of Crescent City, California in an area underlain by dune sands of marine origin. During remediation of sorbed-phase gasoline and diesel range organics (GROs and DROs) and dissolved-phase methyl tertiary butyl ether, target compounds, intrinsic indicators, by-products, and bacterial composition were monitored in the area groundwater and soil. At present, this monitoring has been employed to establish the degree of cleanup of the sands. In this paper the use of the DED model to verify the degree of cleanup of the sands is presented. Results indicate rapid degradation of the target compounds from the dissolved phase with gradual degradation from the sorbed phase. Degradation of the sorbed phase GROs and DROs was indicated by periodic spikes in dissolved-phase concentrations, which are interpreted as representing desorption events. Co-located soil and groundwater samples were collected at intervals of approximately six to nine months. Results from this verification sampling were modeled using the DED. We hope to find a tool that an investigator at a typical underground storage tank site can use to gauge the success of remediation systems. So far, the DED appears to correlate with samples collected using standard field techniques. The use of this methodology has application in establishing the degree of cleanup of contaminated sandy dredge sediments.

Herpetofaunal Species Richness of Southeastern National Parks

The Southeast is the stronghold of US herpetofaunal biodiversity and comprises approximately half of the nation's species of amphibians and reptiles, of which about 20% are endemic. However, few areas have been inventoried, thus hampering efforts to monitor and protect populations. We conducted 2-year herpeto-logical inventories of 16 parks within the National Park Service's Southeast Coast Network. We used a wide variety of standard field techniques to document species occurrences and augmented our collecting records with historical data from museums, published literature, and personal collections. We documented the presence of 123 native species of amphibians and reptiles at the 16 parks, with numbers of species ranging between 6 and 64 per park. Many southeastern parks support rich assemblages of herpetofauna.

Integrating aerial videography and digital photography with terrain modelling: an application for coastal geomorphology

The integration of airborne imagery, derived from video and digital camera imagery, with terrain data from ground survey is within the scope of low-budget, small scale geomorphological investigations. Geographical Information Systems (GIS), available on standard desktop computer systems, are suitable for the integration of this imagery with other geomorphological survey data. Different georeferenced datasets can be combined to produce visualisations that can aid interpretation and measurement that may otherwise be difficult to achieve. As with all remote-sensed data, the synoptic view has considerable benefits, especially when combined with ground fieldwork. There are a variety of methods that can be used to collect and process these data dependent upon the aims of the geomorphologist. There is always a trade-off involving the cost, spatial resolution and temporal control for each of these methods, and this trade-off ultimately determines the absolute accuracy and suitability of the imagery for the purposes required. Although it always seems desirable to attempt to collect the highest resolution imagery possible, using the greatest degree of control and results that can enhance the value of standard field techniques. Decisions involving choice of capture equipment, methods of processing, methods of establishing position and attitude, and ground control techniques determine the quality of the imagery produced. The rectified imagery, when combined with digital terrain models, significantly aids the interpretative process and enables features with boundaries visible on the ground to be delimited on the terrain model and related to contour plots. Airborne video is a cheap, easily available and flexible method of producing this imagery. Recent advances in digital techniques have resulted in digital video and digital camera photography becoming alternatives to conventional video. The advantage of using a digital format is that the number of processing steps is reduced with potential savings in equipment, cost and time as well as improvements in resolution and accuracy. Digital camera photography shows particular promise with spectacular improvements in image resolution and continually falling costs making it an increasingly viable alternative to standard photographic film, particularly when the data are to be transferred onto a computer system. The accuracy and resolution that can be obtained are superior to those obtainable from orbiting systems and future availability of sensors covering a variety of bandwidths will enable multi-spectral analysis. The combination of this kind of imagery with terrain data is a powerful one, either for data visualisation and interpretation or for feature definition and measurement of change.

The benefit of Beam's eye view based 3D treatment planning for cervical cancer

Purpose: The aim of this study was to evaluate the possibility of Beam's eye view (BEV) based three dimensional (3D) treatment planning, to reduce portions of organs at risk included in the treated volume without increasing the risk of geographical miss in external beam therapy of cervical cancer.Materials and methods: Three dimensional dose distribution of BEV based 3D treatment plans was compared to the 3D dose distribution derived from a four-field-box-technique using standard portals. A total of 20 patients with cervical cancer stage FIGO IIB and FIGO IIIB was included. Dose distribution in the target volumes and in the organs at risk of BEV based treatment planning, was compared to the dose distribution of the standard field technique using dose-volume-histograms.Results: In 4/20 patients (20%) a geographical miss at the cervix uteri was observed for the standard field technique. The BEV based treatment planning resulted in an adequate coverage of target volume and additionally in a reduction of portions of bladder and bowel volume included in the treated volume (−13.5, −10%). In contrast the BEV based technique resulted in an increase of portions of the rectum volume included in the treated volume compared to standard portals due to a shift of the rectum by the enlarged cervix uteri from its posterior to a lateral position. An overall 7% reduction of treated volume was observed, although the maximum width of lateral fields increased for the BEV technique. Moreover, we have found a remarkable impact of bladder fillings on the amount of bowel and bladder volume included in the treated volume.Conclusion: BEV based 3D treatment planning for external beam therapy of cervical cancer offers a possibility to avoid geographical miss of part of the CTV with reduced portions of bladder and bowel volume included in the treated volume.

Field Diagnosis of Urinary Schistosomiasis by Multiple Use of Nuclepore Urine Filters

It has been recognized recently that the standard field technique for the diagnosis of urinary schistosomiasis, urine filtration using reusable polyamide mesh filters, may give false-positive findings because filters cannot be washed adequately in all circumstances. In this study the alternative filtration method using polycarbonate membrane filters was tested, and the same problem existed. A variety of more vigorous washing procedures was field tested with the conclusion that polycarbonate filters can be washed adequately for reuse by a simple procedure that includes boiling for 5 min in tap water prior to washing with detergent.

River response to inter-basin water transfers: Craig Goch feasibility study

Catchment development programmes, including river regulation, land drainage, flood alleviation schemes and land use changes, can seriously affect the stability of upland rivers. Changes in flow regimes and sediment transport rates occasioned by such activity can result in systematic erosion and deposition along the river. As part of the Craig Goch reservoir development feasibility study an investigation was carried out on the effect of proposed releases from the reservoir on the stability of the rivers Wye, Dulas and Severn. Dominant discharge concepts indicate that regulation will not affect the natural stability of the channel provided that releases do not increase the frequency of flows above bed material transport and bank erosion thresholds. Any increase in the frequency of such flows will cause unnatural instability. Standard field techniques were used to determine the critical threshold discharge for movement of the surface bed material at twenty-two sites on the three rivers. These data, together with simulated flow information at the proposed outfall points, enabled identification of the sections of channel which would experience erosion or deposition as a result of river regulation. Test releases from the Clywedog reservoir confirmed the results of the investigation on the river Severn.

Effects of socialization on the physiological detection of deception

Effects of socialization on the physiological detection of deception using the control question test (CQT) were explored in three mock crime experiments. Subjects were 168 volunteers from criminal, community, and college student populations. Socialization was measured by the Socialization (So) scale of the California Psychological Inventory. All subjects were given a CQT using standard field techniques. The physiological data were blindly evaluated by a semiobjective field scoring technique and previously developed discriminant function. There were no effects of socialization on the accuracy of classification by the semiobjective field scoring or the discriminant function. A modest negative relationship was found between socialization scores and differential reactivity in the CQT as indicated by correlations with the semiobjective ( r = −.22) and discriminant scores ( r = −.17). It was concluded that socialization is not an important variable for field applications of the CQT.

Inventory Costs on Small Forests

Abstract For $1-$4 per acre, the manager of a small forest can apply standard field techniques and computer systems to derive adequate information for decisions on intensive silviculture.

Testing of electronic industries association land-mobile communication antenna gain standards at the national bureau of standards

The Electronic Industries Association has a published standard, EIA RS-329A, "Minimum Standards for Land-Mobile Communications Antennas," Dec. 1975. This standard details the minimum performance requirements and the test methods for evaluating the performance of fixed and base station antennas at frequencies from 25-1000 MHz. Also included in this standard are the specifications for a set of standard antennas for use in various frequency bands. The EIA Antenna Committee, TR8.11, requested the National Bureau of Standards to calibrate the gain of some of these antenna standards. Two antennas were calibrated in the 450-512-MHz band, and two antennas in the 800-900 MHz band. This paper describes in detail the techniques used throughout the measurement program, the results, and the measurement uncertainties. Two basic methods of measuring the gain of the EIA antennas were employed during this calibration. The three-antenna technique was used at some frequencies, and the standard field technique was used at other frequencies. Both techniques are described. The NBS antennas used for the measurements were standard-gain pyramidal horn antennas. The antenna range used for the measurement is described. This is a vertical range using nonmetallic towers and hardware, thus providing essentially free-space conditions in which reflections and multipath problems are minimized. The measurements were made in terms of absolute power gain, i.e., referenced to an isotropic radiator. These results are discussed and also compared to the gain figures listed in EIA standard RS-329A.