The resource has been added to your collection
Terrestrial diagenesis of the Jurassic Navajo Sandstone in Utah explains both sandstone color and iron oxide concretions in "redrock" country. Students look at pictures and can physically examine concretion examples in the laboratory. Important concepts include: porosity and permeability, mobility of iron (through chemical reduction), and sandstone cementation. Complications include nucleation phenomenon (no obvious nucleus in the iron oxide concretions), self organization (relationship of size and spacing of concretions), chemical constituents, and potential multiple events over time in an open system. The activity utilizes new NASA Mars Exploration Rover data from the Opportunity Rover's pictures of the Burns formation, Meridinani Planum (see Mars Exploration Rover Mission (more info) ). Students can compare different characteristics of terrestrial concretions based on visual images plus perform some limited analyses. Examples include: Similarities and Differences in Characteristics: Outcrop scale distributions Weathering and Accumulations In situ distribution Sizes, Shapes (sphericity, joined forms) Degree of cementation Mineralogical composition Questions the students ponder include: Are the processes for the formation of Mars "blueberries" similar, despite physical and chemical differences? What controls the formation of concretions (terrestrial or extraterrestrial)? What are the implications for the presence of water and the movement of fluids? What inferences can be made about the host rock properties based on the textural, shapes or other characteristics of the concretions?
This resource has not yet been reviewed.
Not Rated Yet.