Below are listed terms and definitions to help you complete this lab. Sedimentary strata are horizontal, or nearly so, when deposited. Strata that are not horizontal have been deformed by movements of the Earth's crust. In any section of undisturbed sedimentary strata, the oldest stratum is at the base and youngest is at the top. Free streaming cartoon sex order of deposition is from the bottom upward. A rock body or feature that cuts across another rock body or feature is the younger of the two.
Placing of events in the order in which they occurred without any relationship to the actual time during which any one event occurred is known as relative dating.
It is a qualitative way of describing the sequence of events. The sequence orders the events but provides no information to the amount of time passed or between events.
To determine the sequence of geologic events, several principles must be followed. The principle of uniformitarianism was first stated by James Hutton in the 18th century. Hutton realized the events in the earths past can be understood by observing the processes seen today. Natural processes such as erosion and deposition, plate tectonics and the laws of gravity and Looking to live and laugh again produce the features of the Earth.
Principle of original horizontality
These processes have not changed. For example, the processes that transport and deposit sediment in a river are the same today as they were a billion years ago. Therefore, if rocks are tilted, folded or metamorphosed, then these events must have followed deposition and lithification. See Original Horizontality and Superposition. Sediments are deposited laterally in continuous layers.
Relative dating sequence of events lab
Meet people and chat if horizontal strata are dissected by erosional features, such as a valley, they can be interpreted to be the same strata. In a series of undisturbed layered rocks each successive layer above is younger than the layer below it. Therefore, the oldest rocks are at the bottom of the sequence and the youngest are at the top.
Any geologic feature that crosscuts or modifies another feature must be younger than the rocks it cuts through. The cross-cutting feature is the younger feature because there must be something ly there to cross-cut. Cross-cutting features can include folds, faults, and igneous intrusions.
They can also include events like metamorphism. In the diagram below Figure 0the igneous dike D must be younger than fault A and igneous intrusion Bbecause it cuts across these and other features. A rock that contains fragments or pieces of another rock must be younger than the pieces of rock that it contains.
Sedimentary rocks can contain clasts of other rocks such as pebbles in a conglomerateor igneous rocks can contain xenoliths foreign rock fragments; figure Okotoks sluts wanting sex which were ripped from surrounding rocks by the magma. Uniformitarianism The principle of uniformitarianism was first stated by James Hutton in the 18th century.
The principle of lateral continuity Sediments are deposited laterally in continuous layers. : Geologic Time. Next: Unconformities. Share This Book Share on Twitter.