Both sea level and land-level may change creating an overall rise in sea level. Both sea level and land-level may change creating an overall fall in sea level. Limestone b. Basalt c. When discussing metamorphic rocks a. grade refers to how nice they look when used in structures by builders. The Potassium-Argon method always produces estimated ages that are older than the true age of the sample.
Mud cracks form when water is only a few millimeters deep.
Raindrop imprints may form when the sediment surface is exposed to the atmosphere. Graded bedding develops when sedimentation occurs rapidly from suspension. In graded bedding, grain size changes from fine at the base of a bed to coarse to its top. Dune cross-bedding may form in air, rivers, and on the sea floor. A formation is a distinctive layer or series of rock layers that are geographically extensive.