Veins of red dolomite occur extensively in the Dalradian rocks of Argyll, Scotland and adjacent areas. The veins represent brittle extensional deformation, preferentially reactivating Caledonian quartz veins. The dolomite is associated with reddening of the adjacent Dalradian country rock, which it partially replaced. Dolomite was also precipitated in overlying Old Red Sandstone, and probably dates to late Carboniferous–early Permian. Fluid inclusion studies show that the veining involved moderate- temperature (75 to 115 °C) fluids. Stable isotope data suggest that these fluids were basinal brines. Traces of chalcopyrite, paragenetically late in the veins, may reflect the mineralization which occurs more widely in the Dalradian rocks of Argyll. The red colour of the dolomite is due to abundant haematite crystallites that grew in the dolomite crystal fabric. Palaeomagnetic analysis yields a consistent late Permian–early Triassic age for the haematite growth in the dolomite veins and the reddened Dalradian country rocks. This age represents the time of haematite precipitation from iron-rich dolomite that may have been related to deep oxidizing weathering. Gold anomalies associated with reddened basement rock must be of this age or younger.

The authors of this article argue both the urgency and the promise of establishing a constructive conversation among different bodies of research, including science interest, sociocultural studies in science education, and culturally relevant teaching. With the instructional practices of eight exemplary African American elementary teachers serving their investigative site, they begin to develop a theory for promoting student interest in science. They argue that this emerging theory is distinguishable by three broad propositions: having a genuine interest, scaffolding student interest, and offering multiple standpoints. They further show that their theory based on these three related propositions has provided an important framework to better understand a number of important issues in science education (e.g., early interest in science and hands-on science activities).

Background/Context Despite the best intentions to close the achievement gap, the under-achievement of African American students in science is a persistent problem. It is surprising to note, however, that research on science education has often failed to consider students’ cultural diversity as it relates to science education. On the few occasions when efforts were made to link science disciplines and students’ cultural backgrounds, these studies were largely limited to classroom learning environments. Purpose/Research Question This study examines the perspectives of exemplary African American teachers toward science homework. Specifically, we address two research questions: What does science homework mean to exemplary African American science teachers? How do they approach science homework? Research Design A qualitative study was conducted, with data obtained from the following sources: (a) three open-ended, in-depth interviews with each exemplary teacher during the first year of the study, and (b) two focus group interviews with these teachers during the second year of the study. The participants were 8 exemplary African American science teachers in Grades 3–6 in the southeastern United States. Findings/Results Data revealed that these teachers shared a strong sense of urgency to use homework as an important vehicle in science learning. To help their students be successful with their homework, these teachers often provided additional provisions and used a variety of strategies to promote students’ interest in their homework. In addition, the teachers adapted an approach comparable to both Boykin's Afrocultural ethos (e.g., concerned with affect, expressive individualism, and verve) and “being a warm demander” (i.e., setting high expectations and insisting firmly yet respectfully that students meet those expectations). Conclusions These findings suggest that there is merit in integrating these two frameworks to better understand the perspectives of exemplary African American teachers toward science homework. These findings highlight the need to examine the perspectives of exemplary African American teachers toward secondary school science homework given that the poor achievement of African American students becomes more pronounced as they progress through school, and homework is found to be more strongly associated with secondary school students than elementary school students.

Palaeomagnetic and geochemical studies of Cambrian-Ordovician serpentinite in the Highland Border Complex (HBC), a tectonic terrane along the Highland Boundary Fault (HBF) in Scotland, indicate that the HBF was a conduit for fluids in the Carboniferous-Permian. The fluids caused dolomitization, silicification, and haematite authigenesis. Both red dolomitized serpentinite and relatively unaltered serpentinite were sampled at multiple localities. The unaltered serpentinite contains a poorly defined magnetization with westerly declinations that resides in magnetite and has a pole which plots well off the apparent polar wander path. Most specimens of the red dolomitized serpentinite contain a magnetization with southerly declinations and negative inclinations that resides in haematite. A regional fold test suggests that this magnetization post-dates tilting and the pole positions for the different locations fall on the Carboniferous to Permian part of the apparent polar wander path. In some specimens of red dolomitized serpentinite, alternating field (AF) demagnetization prior to thermal treatment removes a component with a similar direction. Dolomitized basement rocks along the fault contain a similar although apparently slightly older magnetization. Fluid inclusion and geochemical studies indicate that the fluids were hydrothermal in origin (110-2408C) and had a range of sources. The Carboniferous-Permian magnetization in haematite is interpreted as a chemical remanent magnetization that formed when warm fluids moved along the fault zone and caused haematite authigenesis. The component removed by AF treatment is interpreted as a thermal resetting of primary magnetite by the fluids. The variability of the palaeomagnetic, fluid inclusion, and stable isotope results suggests that there were probably multiple flow events that caused the alteration. The origin of the fluids could be related to the intrusion of late Carboniferous dikes in central Scotland and/or to reactivation of the HBF in the Carboniferous-Permian.

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