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Abstract: Drill core FC77‐1 on the flank of the central uplift, Flynn Creek impact structure, Tennessee, contains 175 m of impact breccia lying upon uplifted Lower Paleozoic carbonate target stratigraphy. Sedimentological analysis of this 175‐m interval carbonate breccia shows that there are three distinct sedimentological units. In stratigraphic order, unit 1 (175–109 m) is an overall coarsening‐upward section, whereas the overlying unit 2 (109–32 m) is overall fining‐upward. Unit 3 (32–0 m) is a coarsening‐upward sequence that is truncated at the top by postimpact erosion. Units 1 and 3 are interpreted as debris or rock avalanches into finer sedimentary deposits within intracrater marine waters, thus producing progressively coarser, coarsening‐upward sequences. Unit 2 is interpreted to have formed by debris or rock avalanches into standing marine waters, thus forming sequential fining‐upward deposits. Line‐logging of clasts ranging from 5 mm to 1.6 m, and thin‐section analysis of selected drill core samples (including clasts < 5 mm), both show that the Flynn Creek impact breccia consists almost entirely of dolostone clasts (90%), with minor components of cryptocrystalline melt clasts, chert and shale fragments, and clastic grains. Cryptocrystalline melt clasts, which appear isotropic in thin section, are in fact made of exceedingly fine quartz crystals that exhibit micro‐Fourier transform infrared (FTIR) and micro‐Raman spectra consistent with crystalline quartz. These cryptocrystalline melt clasts are the first melt clasts of any kind to be reported from Flynn Creek impact structure. [ABSTRACT FROM AUTHOR]

The instructor of an integrated science course for nonscience majors embedded content-related video segments from YouTube and other similar internet sources into lecture. Through this study, the instructor wanted to know students' perceptions of how video use engaged them and increased their interest and understanding of science. Written survey responses from students supported assertions that the videos helped to keep students' attention, generated interest in science, and clarified understanding. Students cited the benefit of visual learning along with the lecture in helping them understand scientific processes and principles. Video provided students with memory cues and connections that also helped them remember conceptual ideas. Students preferred shorter video segments of higher quality that were specifically content related. [ABSTRACT FROM AUTHOR]

The Wetumpka structure, an arcuate, 7.6 km diameter, rimmed feature of the inner Coastal Plain, Alabama, is a Late Cretaceous shallow-marine impact crater. In this paper, we show unequivocal evidence of Wetumpka’s impact origin. Within and about this structure, pre-existing Upper Cretaceous stratigraphy was resedimented and(or) deformed, thus creating distinctive intra-structure and extra-structure terrains. These terrains are located, respectively, within Wetumpka’s crystalline-rim terrain and adjacent to the structure on the southern side. Core drilling near the structure’s geographic center revealed that Wetumpka’s basin-filling sequence has two distinctive units, suggestive of a two-stage filling process consisting of (1) fall-back plus resurge followed by (2) a later secondary seawater resurge event. Wetumpka’s lower subsurface unit includes polymict impact breccias, which contain quartz grains displaying shock-characteristic multiple sets of planar deformation features. Selected subsurface samples of this breccia also contain elevated Ir, Co, Ni and Cr concentrations indicative of a minor extraterrestrial component. [Copyright &y& Elsevier]