EESA06H3 Lecture Notes - Lecture 7: Great Unconformity, Radioactive Decay, Principle Of Faunal Succession
Document Summary
Relative dating: age of rocks relative to another rock. Principles of relative dating: sediments are deposited in horizontal layers. Numeric dating: assigning relative numbers to rocks using analytical measurements. Age of a surface landscape is determined by comparing the relative age of an older rock to the rock on the surface. Sedimentary layer is deposited on an igneous and or metamorphic layer. Once the layer become lithified weathering and erosion can take place to develop the landscapes. Unconformities are eroded surfaces that are buried beneath young layers. Represent large interval of time missing from the rock sequence. Angular unconformities: underlying layers are tilted before new layer deposits then the unconformity is angular. Disconformities: no tilted rock layers, caused by erosion or long period of little to no deposition. Done by a method called numerical dating methods. Involves chemical analyses of rock for products of natural radioactive decay.
