Iron ooid beds of the Carolinefjellet Formation, Spitsbergen, Norway

Iron ooid beds are unusual deposits that have been linked to greenhouse conditions and the transgressive flooding of shallow shelves, and which were globally prevalent during certain periods. Within the marine, Aptian-Albian, Carolinefjellet Formation of Spitsbergen, chamosite ooids have been found within distinctive sandstone beds at six localities, and at a consistent stratigraphic position within the basal Dalkjegla Member. Distinctive characteristics include the iron ooids themselves, a coarser grain size, intercalation with silty siderites, grading, cross-beds indicating offshore or longshore transport, and a lack of burrowing. The enclosing sands display planar and hummocky crossstratification and abundant oscillation ripple marks, and are interpreted as lagoon-attached bar complexes. The stratigraphic position and traits of the iron ooid sands are consistent with seaward storm transport and preservation within interbar swales. Ooids vary in shape considerably, and display evidence for multiple growth events. Nuclei of quartz, opaques, carbonate clasts and laminated crusts are typically encircled by finer grained tangential chamosite and opaque laminae, sometimes with outer overgrowths of calcite and/or radial chamosite. The Dalkjegla Member is the marine portion of a large-scale transgressive tract, attached to underlying fluvio-estuarine Helvetiafjellet Formation strata. A lagoonal environment associated with the basal shales of the Dalkjegla Member represents a logical setting, where riverine iron concentration and iron silicate growth could occur. The Spitsbergen iron ooid beds extend the known occurrence of Cretaceous examples, representing a less common High-Latitude example, and one not directly associated with a transgressive flooding surface

Petrography of Lower Cretaceous sandstones on Spitsbergen

The sandstone petrography of sample suites from four sites spanning the Rurikfjellet (Hauterivian) to Carolinefjellet (Aptian–Albian) formations in central Spitsbergen was investigated. The sandstones show a distinct stepwise shift in composition from quartz arenites to sublitharenites and lithic arenites, typically within the upper part of the Helvetiafjellet Formation. This shift is related to the introduction of 10 - 25 % (grain %) plagioclase grains and volcanic lithics, and a notable increase in basement and sedimentary lithics. Quartz grain character also changes, and grain shapes become more varied. The shift is also associated with the transgressive arrival of marine sediments in the area, and the introduction of sands from the east-northeast by shore-parallel transport. Regional regression and subsequent transgression, and the change in sandstone composition is attributed to the development of the High Arctic Large Igneous Province in the region. The relative constancy of sand composition and volume of volcanic detritus within the Carolinefjellet Formation suggests long term (≈ 20 M) stability of the sediment system and a large volcanic source area, consistent with LIP (Large Igneous Province) derivation, along with significant exposure of basement rocks. Sample spacing and sediment recycling and mixing do not allow detection of events that would have changed sandstone composition that were less than ≈ 1 M duration. Preservation of significant amounts of plagioclase in a sediment-starved shelf can be explained by relatively cold climatic conditions

Strontium isotope stratigraphy and age estimates for the Leisey Shell Pit faunas, Hillsborough County, Florida

The vertebrate fauna of the Leisey Shell Pit near Tampa Bay, Florida, represents one of the more significant lrvingtonian mammalian faunas of North America. The fossil vertebrates occur in thin bone beds bounded above and below by massive shell beds containing a rich invertebrate ( chiefly molluscan) fauna. Debate has arisen concerning the precise age of the faunas at Leisey. Although generally agreed to be Pleistocene, estimates based upon vertebrate biostratigraphy suggest a somewhat older age than do estimates based upon molluscan biostratigraphy. To help resolve this controvefliy, 87Sr/86Sr ratios were determined on molluscan shells throughout the section. These ratios were then correlated to the global sea water 87Sr/86Sr curve for age detennination. The Sr isotopes support an early Pleistocene age for the vertebrate fauna and suggest a complex history for the shell accumulations

Improving Student Attitudes about Science by Integrating Research into the Introductory Chemistry Laboratory: Interdisciplinary Drinking Water Analysis

The integration of student research into a general chemistry laboratory and an environmental geology course has been evaluated for its effectiveness to improve (i) student attitudes about science and chemistry, (ii) student understanding of the nature of experimental science and the scientific method, and (iii) student perceptions of the application of science and the interdisciplinary nature of science. Students in introductory science courses frequently devote all or most of their time and effort to learning basic laboratory techniques by following predefined procedures that have intentionally predictable outcomes. Though this longstanding model of laboratory structure is an important means of effectively preparing students for future chemical study, it often neglects items i−iii. Students were guided through a research experience by an interdisciplinary team of faculty so that students could begin the research and bring it to an appropriate conclusion, including formal presentations, within a single semester. Evaluation of this instructional strategy indicated that students believed they were doing work similar to a research scientist, that they appreciated this opportunity to do research, that it increased how much they like science in general, and that they were more likely to consider majoring in chemistry. The advanced instrumentation, personal relevance of the research, and collaborations (within and outside the department) contributed significantly to the overall success of the project

U-Pb Studies of Zircon Cores and Overgrowths, and Monazite: Implications for Age and Petrogenesis of the Northeastern Idaho Batholith

U/Pb isotopic studies of zircons, many containing xenocrystic cores with euhedral overgrowths, and monazite from igneous rocks and metasedimentary inclusions of the northeastern Idaho batholith yield linear arrays on concordia diagrams. We interpret these as mixing lines between an old component (cores) and a young component (overgrowths and zircons without cores). The lower intercept of such arrays with concordia may yield the minimum age of the rocks if the overgrowths and zircons without cores are discordant, or the crystallization age if they are concordant. Monazites yield apparently concordant ages either equal or less than the lower intercept zircon ages. The samples studied yield lower intercept ages ranging from 73.5+ or -6 Ma (foliated quartz diorite) to 46.5+ or -1 Ma (feldspar megacryst granite); ages obtained are consistent with crosscutting relations observed in the field. Upper intercepts yield ages of 1700 to 2349 Ma. These are interpreted to indicate the mean age of xenocrystic zircon. Studies of zircons from xenolith suites indicate that they could represent the source of the old zircon component. The zircon and monazite results, the generally high initial 87Sr/86Sr ratios of the igneous rocks, and the isotopic composition of Pb in feldspar indicate that the magmas were derived anatectically from a continental crustal source or were extensively mixed with such old crust prior to or during emplacement

Enhancing the STEM Ecosystem through Teacher-Researcher Partnerships

STEM faculty at the University of Nebraska at Omaha (UNO) have partnered with teachers and administrators in the Omaha Public Schools (OPS) to implement a Teacher-Researcher Partnership Program. This program establishes resources and infrastructure that engage K-12 science teachers in scientific research experiences. In the first implementation of this program, eleven UNO faculty mentors, drawn from several STEM disciplines, were matched with eleven OPS teachers to conduct genuine research projects in support of their teaching

Source of the northeastern Idaho batholith: isotopic evidence for a Paleoproterozoic terrane in the northwestern U.S.

The northeastern portion of the Idaho batholith (NIB) intruded Proterozoic rocks of the Belt-Purcell supergroup between SO and 90 Ma. Whole-rock Sm-Nd isotopic analyses of batholithic rocks yield depleted mantle model ages (T oM) between 1. 72 and 1.93 Ga and values of eNd between -17. 7 and - 21.2, similar to associated metamorphic rocks and within the range for Belt-Purcell sedimentary rocks. Premagmatic zircons from one sample of the NIB were analyzed individually using the SHRIMP ion microprobe and yielded a single age population at 1.74 Ga. This apparently single-aged source contrasts with the range of ages reported for zircons from sedimentary rocks of the Belt-Purcell supergroup and suggests that the batholith was not the product of melting Belt-Purcell sediments, nor was it significantly contaminated with these sediments. The source of the batholith, however, appears to be of appropriate age and composition to be a major contributor of sediment to the Belt basin. In addition, the near coincidence of TOM and the age derived from premagmatic zircons in one sample suggests the source of at least part of the batholith was extracted largely from 1.74 Ga depleted mantle, with little or no input from older rocks. If so, this crust may represent a possible continuation of crust of similar age and character exposed to the north in the Canadian cordillera and to the south in Nevada, Arizona, and southeastern California

Genuine Faculty-Mentored Research Experiences for In-Service Science Teachers: Increases in Science Knowledge, Perception, and Confidence Levels

The overall purpose of this multifocused study was to explore how participation in genuine mentored scientific research experiences impacts in-service science teachers and the knowledge and skills needed for their own science teaching. The research experiences resulted from a partnership between the University of Nebraska at Omaha and the Omaha Public School District. This Teacher- Researcher Partnership Program facilitated opportunities in inquiry, science content, interaction with laboratory instrumentation and technologies, critical discussion of literature, and dissemination of findings for participating in-service science teacher professional development utilizing an inquiry-based theoretical framework wherein we examined science teacher preparation via inquiry-based methods in the research laboratory. A mixed-methods approach with a convergent typology (i.e., qualitative and quantitative analyses conducted separately and integrated) was used to investigate the impact of the program on teachers. Our research question was as follows: How do teachers define and approach scientific research before and after a genuine research experience? We observed 3 emergent nodes or themes by which teachers indicated significant gains: science content knowledge, confidence, and perception. Moreover, we determined that participation by science teachers in a mentored research experience using current scientific technologies and tools improved teacher confidence in science and inquiry as well as an ongoing commitment to provide similar types of experiences to their students. These data support the need for the participation of in-service science teachers in genuine research experiences to boost technological and pedagogical content knowledge, confidence in process and content, and the perception of translatability to the classroom

Initial results of an online Earth System Science course offering at the University of Nebraska at Omaha

he University of Nebraska at Omaha has been offering on-line Earth System Science coursework to teachers in Nebraska since 2002. UNO was one of the initial members in the Earth Systems Science Education Alliance (ESSEA) and has offered three different ESSEA courses, with nearly 200 students having taken ESSEA courses at UNO for graduate credit. Our experiences in delivering this coursework have involved both teachers who have received a stipend to take the course and those who have paid their own tuition and fees and received graduate credit for the course. We will report on the online behavior of teachers from both populations and also discuss pros and cons of each approach. UNO has also experimented with different approaches in the support and management of the course, including using undergraduate majors as content experts. This improves access of teachers to content-related feedback and is a positive experience for the undergraduate major. Feedback surveys from earlier ESSEA offerings indicate a strongly positive perception of the courses by the teachers enrolled in the coursework. Project impact has been documented in teacher projects, quotes, and lessons associated with the coursework activities. We will also describe online course modules being developed within the UNO online course efforts, including one focusing on the global amphibian crisis

\u3ci\u3eRoadside Geology of Nebraska\u3c/i\u3e

Nebraska\u27s geology is as exciting as the Cornhuskers. The state hosts boiling riverbeds, puzzling fossil beds, and sandstone toadstools, not to mention a now dormant sea of sand that once moved fast enough to dam rivers; and these Sand Hills could be on the march again as the global climate warms. Changing climate influenced much of Nebraska\u27s geology, from the waxing and waning of continental glaciers to the extinction of some of Nebraska\u27s former inhabitants. You\u27ll discover badlands, braided rivers, fossil rhinos entombed in volcanic ash, and the largest dune field in the Western Hemisphere.https://digitalcommons.unomaha.edu/facultybooks/1048/thumbnail.jp