11. The surface rock in Catawissa Creek largely consists of sedimentary rock, such as sandstone and shale. 12. At Teberibie, rather than digging deep for rich veins, surface rock is fed into a conveyor-belt crusher. 13. Today, the once hot magma chamber is exposed surface rock on the northern shore of Lake Superior. 14. Solid chunks of ochre were ground on a flat but rough surfaced rock to produce the powder. 15. Other threats include off-road vehicle use, grazing, and the mining of surface rock for use as building stone. 16. A chain-driven wheel rotates a graded scoop picking surface rocks from the soil and shakes off excess soil. 17. The Senoueix Bridge is highly likely to have been built on a curve, based on the surfacing rock . 18. This irregular boundary is sometimes defined as the southern extent of Cenozoic igneous surface rock from the Cascade Range. 19. This suggests that neon will be a useful tool in determining cosmic exposure ages of surface rocks and meteorites. 20. Both Pathfinder and its roving vehicle, Sojourner, are operating normally and transmitting pictures and chemical data on surface rocks .
