Geoscience Laboratory Research Articles

Instructional Development of Media-Based Science OER

Video and interactive media provide visual exposition and review for students to formulate cognitive representations where learning and reflection take place, especially in science laboratories. More inclusively, open educational resources (OER) with interactive content can facilitate access to media-enhanced learning. This paper reports part of a multi-year ongoing design-based research (DBR), focusing on the instructional development of media-based OER content in two geoscience laboratory education projects. The researchers have taken a case study approach to analyzing and exploring the design and development of accessible and interactive OER media, including photography and videography space, lighting conditions, camera settings, interactive media production, and OER publishing platforms. Findings have revealed the instructional development procedures, workflow and protocol of generating closed captioning for scientific video, data management techniques, and operability of media content in publishing platforms. The results are of practical and innovative values to the instructional development of science OER.

Acessibilidade para alunos cegos e surdos em uma exposição permanente de Geociências

O crescente ingresso de pessoas com necessidades educacionais especiais nas instituições de ensino superior leva a discussões sobre a acessibilidade em todos os âmbitos da educação. Percebendo tais dificuldades, surgiu a necessidade de adaptar as amostras da coleção do Laboratório de Geociências da UESB, campus de Jequié, de maneira que seja possível o acesso as informações para este público. A fim de adequar a exposição, principalmente para cegos e surdos, foram utilizadas ferramentas facilitadores, a exemplo de QR Code, que proporciona leituras de textos específicos sobre a amostra em LIBRAS, áudio e legendas em português. O principal objetivo do trabalho foi avaliar através do posicionamento das pessoas com deficiência se as alterações realizadas na mostra influenciaram no processo de ensino-aprendizagem. De acordo com os resultados obtidos, através de entrevistas, ficou evidenciado que a ambientação do Laboratório de Geociências da UESB Jequié atendeu as expectativas de visitantes com necessidades especiais à instituição.

Low Permeability Media: A Research Frontier

This thematic dossier collects eight scientific papers corresponding to presentations made during two international conferences dedicated to the study of low permeability media held in Paris within six months of each other. The first conference, “The Challenge of Studying Low Permeability Materials: Laboratory, in situ (field) and numerical methods”, was organised in December 2014 by the University of Cergy-Pontoise (Geosciences and Environment Cergy Research Laboratory) under the aegis of CFMR (Rock Mechanics French Committee) and GIS Geosciences franciliennes. The second, LowPerm2015 “Low permeability media and nanoporous materials from characterisation to modeling: Can we do it better?”, was organised by IFP Energies nouvelles in June 2015 under the aegis of the French “Academie des Sciences”. An attractive and explicit title is key to the success of a conference. It sets the scene and lets possible participants know exactly what matter will be discussed. But subtitles may be as important as titles, because they may stimulate participants by confronting them with a collective challenge. Devoted to characterisation, transport properties and multiscale modeling of low to very low permeability media and nanoporous materials, LowPerm2015 was leaving very little ambiguity about the matter to be discussed. Its subtitle – Can we do better? – was a mild way of stressing that there are several areas where we should be totally unsatisfied about our present state of knowledge, and where progress is urgently needed. One of these areas is the recovery of unconventional hydrocarbon resources. There is no question that the gas and oil shale revolution has deeply changed the global energy landscape, but its long term sustainability is questionable in spite of the tremendous magnitude of the resource due to an unacceptably low rate of recovery. With close to seventy five percent of the gas and ninety five percent of the oil left in place on average, the exploitation of self-sourced organic rich shale reservoirs is one of the least efficient industrial operations. Among the main reasons for this are our poor knowledge of the complex nanoporous void space in which the hydrocarbons are trapped, and our very limited understanding of their release and transport mechanisms, particularly in multiphase conditions. Just imagine what the future would be if, thanks to improved understanding, we could switch from ninety five percent left in place to ninety five percent recovery!

Blank on the Geological Map

This paper summarizes the history of the geological studies performed by Italian teams in the Karakorum-East Hindu Kush ranges (Pakistan and Sinkiang, China) over the past 35 years. These studies began under the direction of Ardito Desio, who was the lead Italian investigator from 1929 to the end of the seventies. The Italian teams were from the universities of Milan, Turin and Pavia and benefited from a fruitful cooperation with Pakistani authorities, mainly the Geoscience Laboratory of the Geological Survey of Pakistan, Islamabad. The main geological features of the Karakorum Terrane are described. To the south, the Southern Metamorphic Belt, the Ghamu Bar Unit and the Gazin–Darkot Metasedimentary Unit are identified. To the east of the Karambar River, they merge in a higher metamorphic degree unit. The Karakorum Batholiths forms the backbone of the Terrane, with isolated plutons intruding also into the neighbouring units. The Northern Karakorum shows the Crystalline Basement of pre-Ordovician age, overlaid by a sedimentary sequence from Ordovician to Jurassic without major unconformities. The deformations building since the Cretaceous the actual range are shortly exposed.

11th International GeoRaman Conference

11th International GeoRaman Conference

U-Pb geochronology and global context of the Charnian Supergroup, UK: Constraints on the age of key Ediacaran fossil assemblages

Research Article| January 01, 2015 U-Pb geochronology and global context of the Charnian Supergroup, UK: Constraints on the age of key Ediacaran fossil assemblages Stephen R. Noble; Stephen R. Noble † 1Natural Environment Research Council Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottinghamshire, NG12 5GG, UK †E-mail: srn@bgs.ac.uk. Search for other works by this author on: GSW Google Scholar Daniel J. Condon; Daniel J. Condon 1Natural Environment Research Council Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottinghamshire, NG12 5GG, UK Search for other works by this author on: GSW Google Scholar John N. Carney; John N. Carney 2British Geological Survey, Keyworth, Nottinghamshire, NG12 5GG, UK Search for other works by this author on: GSW Google Scholar Philip R. Wilby; Philip R. Wilby 2British Geological Survey, Keyworth, Nottinghamshire, NG12 5GG, UK Search for other works by this author on: GSW Google Scholar Timothy C. Pharaoh; Timothy C. Pharaoh 2British Geological Survey, Keyworth, Nottinghamshire, NG12 5GG, UK Search for other works by this author on: GSW Google Scholar Trevor D. Ford Trevor D. Ford 3Department of Geology, University of Leicester, Leicester, LE1 7RH, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Stephen R. Noble † 1Natural Environment Research Council Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottinghamshire, NG12 5GG, UK Daniel J. Condon 1Natural Environment Research Council Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottinghamshire, NG12 5GG, UK John N. Carney 2British Geological Survey, Keyworth, Nottinghamshire, NG12 5GG, UK Philip R. Wilby 2British Geological Survey, Keyworth, Nottinghamshire, NG12 5GG, UK Timothy C. Pharaoh 2British Geological Survey, Keyworth, Nottinghamshire, NG12 5GG, UK Trevor D. Ford 3Department of Geology, University of Leicester, Leicester, LE1 7RH, UK †E-mail: srn@bgs.ac.uk. Publisher: Geological Society of America Received: 13 Oct 2013 Revision Received: 06 Jun 2014 Accepted: 21 Jul 2014 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2014 Geological Society of America GSA Bulletin (2015) 127 (1-2): 250–265. https://doi.org/10.1130/B31013.1 Article history Received: 13 Oct 2013 Revision Received: 06 Jun 2014 Accepted: 21 Jul 2014 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Stephen R. Noble, Daniel J. Condon, John N. Carney, Philip R. Wilby, Timothy C. Pharaoh, Trevor D. Ford; U-Pb geochronology and global context of the Charnian Supergroup, UK: Constraints on the age of key Ediacaran fossil assemblages. GSA Bulletin 2015;; 127 (1-2): 250–265. doi: https://doi.org/10.1130/B31013.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract U-Pb (zircon) ages for key stratigraphic volcanic horizons within the ∼3200-m-thick Ediacaran-age Charnian Supergroup provide an improved age model for the included Avalonian assemblage macrofossils and, hence, temporal constraints essential for intercomparisons of the Charnian fossils with other Ediacaran fossil assemblages globally. The Ives Head Formation (Blackbrook Group), the oldest exposed part of the volcaniclastic Charnian Supergroup of the late Neoproterozoic Avalonian volcanic arc system of southern Britain, contains a bedding plane with an impoverished assemblage of ivesheadiomorphs that is constrained to between ca. 611 Ma and 569.1 ± 0.9 Ma (total uncertainty). Higher-diversity biotas, including the holotypes of Charnia, Charniodiscus, and Bradgatia, occupy the upper part of the volcaniclastic succession (Maplewell Group) and are dated at 561.9 ± 0.9 Ma (total uncertainty) and younger by zircons interpreted as coeval with eruption and deposition of the Park Breccia, Bradgate Formation. An ashy volcanic-pebble conglomerate in the Hanging Rocks Formation at the very top of the supergroup yielded two U-Pb zircon populations: an older detrital one at ca. 604 Ma, and a younger population at ca. 557 Ma, which is interpreted as the approximate depositional age. The temporal association of the fossiliferous Charnian Supergroup with comparable fossiliferous deep-water successions in Newfoundland, and the probable temporal overlap of the youngest Charnwood macrofossils with those from different paleoenvironmental settings, such as the Ediacaran White Sea macrofossils, indicate a primary role for ecological sensitivity in determining the composition of these late Neoproterozoic communities. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Transforming a University Tradition Into a Geoscience Teaching and Learning Opportunity for the University Community

ABSTRACTRecent initiatives in geosciences education have focused on interactive and inquiry-based learning experiences both inside and outside of the classroom. While the concept is sound, examples and datasets seldom focus on opportunities to which the students can immediately relate. Herein we show how a university tradition has been transformed into an interactive geosciences learning opportunity for the university community. Each year during the third week of November, thousands of university students jump into an artificial pond on campus in support of the annual football rivalry game. An undergraduate student research initiative documenting the water quality of the pond before, during, and after the event clearly documents how humans can affect their environment. Use of the resulting dataset in the classroom for an entry-level geoscience laboratory exercise on water contamination has sparked student interest in the effects of anthropogenic activities on water quality and has mobilized subsequent studies to test additional hypotheses. Changes in students' attitudes on water quality were documented by significant differences in administered pre- and postexercise surveys with five-point Likert-type items, while subsequent interest in the dataset from both the university and the surrounding communities has provided additional audiences for engagement on local water contamination issues. Inclusion of the dataset into laboratory exercises is intended to lead to future research questions and promote independent research initiatives.

Macro and microelements in bottled and tap waters of Serbia

Comparative analysis between bottled and tap waters as well as its comparison with current Serbian regulations, European Union Directives and World Health Organization standard are shown in this paper. Thirteen bottled waters and fourteen tap waters from the territory of Serbia were analyzed in the Federal Institute for Geosciences and Natural Resources (BGR) laboratory in Berlin, for the purpose of the ?Geochemistry of European Bottled Water? project conducted by EuroGeo Survey Geochemistry (EGS). Macrocomponents (main cations and anions) of ground waters usually reflect on lithogeochemistry of the aquifer, while microcomponents indicate the circulation of ground water through the different lithological environment. Analyzed bottled waters could be classified as those with low mineral content (M<500 mg/L) if HCO3 anion and Ca and Mg cations were the prevailing ones, or mineral (M>500 mg/L) with prevailing HCO3 anion and Na cation. Waters with low mineral content were mainly from limestone and dolomite, while mineral waters mainly originated from magmatic and metamorphic rocks. Higher content of Cs, Li, Ge, Rb and F in bottled waters indicates the importance of the magmatic intrusions influence on their chemical composition. In some waters higher content of B, I, NH4, as well as of Tl and W has been observed which can be attributed to water?s circulation through different lithological complexes. Tap water was mostly obtained from groundwater (from Neogen and alluvial aquifers and karst springs) with rest being those of rivers and surface accumulations. Tap waters from Central Serbia were with low mineral content, with prevailing HCO3 anion and Ca and Mg cations, while waters from Vojvodina, the northern province of Serbia, were with higher mineralization, HCO3-Na. Chemical analyses of the sampled tap waters showed good quality, with exception of waters from the cities of Senta and Zrenjanin in Vojvodina. High values of B (1170 and 895 g/L), As (20.9 and 71.9 g/l), Na (208 and 275 mg/L), as well as EC (715 and 928 S/cm) have been registered in these waters.

A summary of strontium and oxygen isotope variation in archaeological human tooth enamel excavated from Britain

This paper presents a compilation of strontium and oxygen isotope data from human tooth enamel that has been produced at NERC Isotope Geosciences Laboratory over the last c.15 years. These many and often small studies are here combined to provide an overview of data from Britain. The strontium isotope composition ranges between 0.7078 and 0.7165 (excluding individuals deemed to be of non-British origin). The median Sr concentration is 84 ppm but there is a vector of increasing Sr concentrations related to seawater strontium isotope composition that is seen in individuals predominantly from the west coast of Scotland attributed to the used of kelp as a fertilizer. The oxygen isotope data is normally distributed with a mean value of 17.7‰ ± 1.4‰ (2SD n = 615). Two sub-populations of local individuals have been identified that provide control groups for human enamel values from the eastern side of Britain where there are lower rainfall levels: 17.2‰ ± 1.3‰, (2SD, n = 83) and western area of Britain where rainfall levels are higher = 18.2‰ ± 1‰, (2SD, n = 40). These data make it possible to make direct comparisons of population means between burial populations and the control dataset to assess commonality of origin.

Assessing the Impact of Geoscience Laboratories on Student Learning: Who Benefits from Introductory Labs?

Laboratories serve as an integral part of geoscience education at most colleges and universities. While anecdotal evidence supports the beneficial impact of laboratories on science class learning, little quantitative research backs this statement. This study compared classroom data from students who completed a geoscience laboratory in conjunction with an introductory-level lecture-based course to those who completed the lecture course only. Laboratory-enrolled students performed better in the lecture class, resulting in an increase of 5.5% in their final class score. Even after controlling for GPA, laboratory enrollment accounted for a statistically significant proportion of the variance. Nontraditional students (age 25 and over) primarily benefited from the laboratory. Nontraditional students enrolled in lab performed 21.1% higher overall than their lecture course only nontraditional counterparts, and 4.9% higher overall than traditional students who enrolled in both the laboratory and lecture courses. Geoscience laboratories play a significant role in student learning and appear particularly important for nontraditional students.

Strontium and stable isotope evidence for diet and mobility in Roman Gloucester, UK

This paper presents the results of a multi-isotopic (oxygen, strontium, carbon and nitrogen isotopes) investigation of population and dietary diversity in Roman Gloucester, focusing on individuals found in a late 2nd century AD mass burial pit at London Road, and comparing them to those found in the nearby cemetery. There were no statistical differences in isotopic composition between mass grave and cemetery burials, suggesting, in agreement with the osteological evidence, that the mass burial was the result of a catastrophic event, probably an epidemic disease. Strontium and oxygen isotope analysis demonstrated considerable diversity in the origins of the Gloucester population, with evidence for both UK and non-UK individuals. Diet was predominately terrestrial and similar to that of other Romano-British populations. Elevated δ 13C dentine ratios in some individuals are correlated with raised δ 18O p values and are therefore probably due to childhoods spent in warmer climates, rather than dietary variation. Given the geological complexity of the Gloucester area, this study also provides new biosphere 87Sr/ 86Sr data for the wider region. A technical Appendix gives details of the analytical methods employed by the NERC Isotope Geosciences Laboratory (NIGL) for the measurement of oxygen stable isotope ratios in biogenic phosphate (δ 18O p). It also evaluates different phosphate oxygen-drinking water conversion equations using data from Britain.

An Exploratory Study into the Multidimensional Nature of Quality in Analytical Laboratories: Managerial Implications

The management of quality in analytical laboratories is heavily biased toward assuring the quality of the data produced by laboratories, with little or no attention being given to the way in which customers are served. To investigate the nature of laboratory quality, a modified SERVQUAL instrument was used to determine the expectations of laboratory staff members, and internal and external clients at the Council for Geoscience Laboratory in South Africa. The results suggest that laboratory quality is dichotomous in nature, consisting of aspects related to both technical and functional quality. Although technical quality is regarded as more important by the customers and laboratory staff members surveyed than functional quality, the latter is also very important to customers when deciding which laboratory to employ. This has important implications for the management of quality in laboratories, where technically trained personnel may have to be sensitized to the functional quality needs of their customers. Conflicts of interest that may arise when trying to meet both functional and technical quality expectations of customers need to be identified by laboratory managers and managed accordingly.

Teaching the Mathematics of Radiometric Dating

Helping college students understand how we determine the numerical ages of rocks, the fossils they contain, the Earth, and the solar system can be difficult, but such questions are central to the science of geology and certainly deserve the effort. Regrettably, the overwhelming majority (about 90%) of modern introductory geoscience textbooks and laboratory manuals neglect the subject of numerical dating by attempting to present the subject completely without mathematics of any kind. This has been the case, as far as I have been able to determine, throughout the 20th century, or, to put it differently, ever since radioactivity was first discovered and radiometric or isotopic methods of age determination were first developed. What I found through a short survey of introductory college-level books was that only a small fraction (about 5%) of books include a graph showing the exponential increase of daughter/parent ratio with age, and that relatively few (only about 20%) present the fundamental equation for dating. Both of these surprising facts strongly suggest that, in a misguided effort to pander to the mathematical and numerical illiteracy of contemporary students, a central finding of geology has been and is being superficially treated in the great majority of modern introductory geoscience books. Correcting this glaring inadequacy ought to be one of the fundamental objectives of any effort to improve our teaching of the fundamental facts, concepts, and methods of modern geology.

A Revised Physical-Geology-Laboratory Curriculum Based on Group Learning

Providing a high-quality educational experience for large introductory geoscience laboratories is an ever-increasing challenge. The constraints involved include balancing materials, space, and schedules for multiple sections, coordinating several to many graduate teaching assistants (GTAs), and maintaining quality where funding cuts have removed financial support for basic materials and staff (specifically, a laboratory coordinator). We have met these challenges by changing to a constructivist pedagogy, by emphasizing small-group collaboration and dynamics and by introducing graduate teaching assistants (GTAs) to alternative teaching models. Course pedagogy has changed from a classic expository style with GTAs as talking heads in which students worked independently from a laboratory manual to a discovery-based, collaborative-learning environment with GTAs as facilitators guiding inquiry, in which students work in small groups on exercises specific to our local environment. The course has two components: (...

Perspective. Method validation in the Ontario Geoscience Laboratories

In 1992, the Ontario Geoscience Laboratories (hereafter referred to as the Geoscience Laboratories) moved from Toronto to Sudbury into a new 25 000 ft2 facility. The acquisition of an extensive bank of new equipment and many staffing changes meant all methods were revised and then validated. Thus 7 single element tests, 2 precious metal packages, 2 major element packages by XRF, 7 elements determined by AA, 11 elements by ICP-OES, 8 elements by XRF and 24 elements by ICP-MS were validated. These methods represent the program needs of much of the Ontario Geological Survey. The task had to be completed ‘as soon as possible’ to minimize the impact on the mapping programs of the Survey which were not interrupted by the move. The tasks of building implementation, method development and validation were undertaken by approximately 12 staff members and were completed in 12 to 18 months. Method validation ensures that a particular analytical methodology using a specific combination of techniques will yield an analytical result that is proven to be correct. It is critical to perform such exercises when procedures are instituted or changed, new equipment procured or staff hired to ensure continuity of data quality. A generic validation program was documented, streamlined and used by all. A detailed outline was drawn up that explained the exercise and listed the steps required. For each method and element, precision, trueness, detection limit, quantification limit, working range, blank level and lack of inherent bias were quantified. These parameters were based on data from a minimum of seven replicates of five to seven SRMs that spanned a wide geological range. SRMs used in calibration or method development could not be included. The data quality objectives were approximately ± 5% precision (2σ) and trueness to meet the stringent data quality objectives of the Geoscience Laboratories. Here, over a 5-year period, precision and trueness are not expected to exceed ± 10%(2σ) when the concentration of an element is more than three times the limit of quantification or 10 times the limit of detection (LOD = 3so). Overall, the exercise was a resounding success. Data from the validation of Ba is used throughout the text to illustrate the principles discussed. The problems that were encountered typically included the availability of certain rock compositions, the level of characterization of some reference materials, the uncertainty on ‘known’ values and thus method trueness, the definition of detection limit and the difficulty in getting realistic ‘blank’ determinations for some methods. For the Geoscience Laboratories, the method validation exercise provides a standardized, non-subjective means to ensure the data quality objectives of the facility are met. It also convinces management, staff and clients that an appropriate level of expertise is achieved.

Perspective. Certified Ontario reference materials programme at the Geoscience Laboratories, Sudbury, Ontario, Canada

The Ontario Geoscience Laboratories (hereafter referred to as the Geoscience Laboratories) have produced 30 in-house materials since 1970. This experience, the limited availability of international rock standards in volume, and the recent acquisition of specialized equipment (capable of homogenizing up to 1 t of sample), has led to the development of the Certified Ontario Reference Materials programme for the production of certified reference materials (CRMs). Given the geological diversity of Ontario, the decision was made to create two streams of reference materials. One is a suite of unaltered and altered volcanic rock reference materials that reflected the wide compositional range of Archean rocks of Ontario. Sample sites are clustered in the Abitibi Greenstone Belt which includes the Timmins and Kirkland Lake mining camps. This region also hosts some of the world's largest and most prolific mines of Au and Cu–Zn, smaller Ni deposits and one of the two international type-localities of komatiite. Advantages of such a choice are extensive. The rocks in this area have been studied by the Ontario Geological Survey (OGS) for 50 years and this expertise is readily available both in terms of appropriate chemistry and in sampling sites. Geologically, Archean volcanic rocks were typically extruded into a subaqueous environment and cooled quickly. This facilitates a high degree of homogeneity. There are a wide variety of compositions available, clear association with mineral deposits and thus the reference materials may also provide excellent baseline material for environmental studies. In the 1970s, the OGS devised internationally used major element classification criteria which divided Archean volcanic rocks into three major clans that have several subtypes (komatiitic clan has ultramafic and basaltic members; tholeiitic clan has Fe-, Mg-, basaltic, dacitic, andesitic, and rhyolitic members; and calc-alkalic clan has basaltic, andesitic, dacitic and rhyolitic members). These rock types typically show different styles of alteration near ore deposits (i.e., chloritization, sericitization, carbonatization). The Archean volcanic rock suite will be comprised of these unaltered and altered rock types. The other group will focus on materials that fill a specific geoanalytical need. Based on the information above and the capacity of the Geoscience Laboratories geostandards programme (5 CRMs per year), it is anticipated that several rock types will be prepared yearly. A calc-alkaline rhyolite and an ultramafic komatiite have now been collected and other sites have been identified. Collection has commenced. After the sample is bottled, the homogeneity will be tested in our laboratories using validated methods. This will provide a tentative composition and will be followed by round-robin determinations. The reference materials will be released in 100 and 500 g plastic bottles to both the geoanalytical community and the exploration industry to monitor precision and accuracy in commercial surveys.

U.S. Geoscience Community gains an absolute gravimeter

An FG5 absolute gravimeter, which measures the gravitational acceleration of a retroreflector falling freely within an evacuated tube, is now available for use by U.S. university investigators. It will be housed as a National Science Foundation facility at NOAA's Table Mountain Gravity Observatory of the Geosciences Laboratory in Boulder, where similar units are prepared for worldwide deployment.U.S. investigators are invited to apply the FG5 gravimeter to geophysical investigations of gravitational acceleration that require microgal accuracy and unequivocal long‐term stability. The instrument is expected to be used in more than a dozen projects each year. Funding for geophysical applications of the device will be subject to normal peer review processes; in case of scheduling conflicts, the allocation of time on the gravimeter will be refereed by a user committee.

A Computer-Simulation Laboratory Exercise on Water-Quality Modelling

Computer simulation of the effects of biodegradable waste on the oxygen resources of streams provides students with the opportunity to investigate the response of a natural system to external influences. Students can use the model to explore the impact of changing variables in the system and, ultimately, to judge the value of wastewater treatment. This report on a microcomputer-based geoscience or physical geography laboratory exercise provides a brief introduction to wastewater treatment, the impact of wastewater disposal on the dissolved-oxygen resources of a watercourse, and the process of reoxygenation in the watercourse. Using appropriate equations for oxygen depletion and reoxygenation, a computer simulation of stream impact and recovery processes has been developed for use in a laboratory course. With this model, students can test the effects of changing such parameters as wastewater loading, water temperature, and reaeration coefficients on the oxygen content of the modelled stream. Students are i...

The determination of scandium, yttrium, and selected rare earth elements in geological materials by inductively coupled plasma optical emission spectrometry

The spectroscopic determination of rare earth elements (REE's) in geological matrices is generally complicated by the relatively low concentrations of these elements, the high concentrations or matrix elements and their interferences in the analyte determination and a lack of well-defined usable concentration values for reference rock materials, especially at low REE concentrations. This paper describes work being carried out at the Geoscience Laboratories, Ontario Geological Survey, on the determination of Sc, Y, and selected rare earth elements at both high concentration and chondrite levels by inductively coupled plasma optical emission spectrometry. Direct acid digestate solutions (for high concentrations) and ion exchange separated solutions (for chondrite levels) are analyzed by a multichannel ICP spectrometer system: typical results for reference standards and samples are presented and compared.