Correlation And Dating Flashcards
What are Steno’s Principles?
- Superposition
- original horizontality
- lateral continuity
What is superposition?
Younger rock layers over older rock layers
What is original horizontality?
Deposited in horizontal layers as a liquid to fill in spaces but smooth out at the top
What is lateral continuity?
layers of sediment are continuous, unless a barrier prevents the sediments from spreading during deposition, or subsequent changes in the landscape break those sediment layers apart.
What is the principal of cross-cutting relationships?
New geologic features disrupt (cut) older ones
What is stratigraphy?
The study of rock strata, especially the distribution, deposition, and age of sedimentary rocks.
- Stratified rocks
- geometric relations
- compositions
- origins
- age relations
What was Smiths map based on?
The principle of fossil succession
- fossils occur in a predictable order in rock.
What is correlation?
The process of demonstrating correspondence between geographically disparate stratigraphic units.
What is disparate?
Different - not comparable
What is lithostratigraphic correlation?
Linking rock units of a similar age.
What is temporal correlation?
Linking rock units of a similar age
What is relative dating?
How to determine the order of events in the rock record.
Explain Sedwick and Murchison dispute.
Sedgwick discovered and named the time period known as Cambrian. Sedgwick helped fellow geologist Murchison discover the Devonian period. They were friends until they both wanted to claim the same rock strata for their periods Sedgwick for Cambrian and Murchison for what he called Silurian. A geologist named Lapworth settled the dispute by assigning the older rocks to the Cambrian period and the newer rocks for the Silurian period carving out a period called Ordovician for the rocks in between.
Sedgwick and Murchison:
- Cambrian and Silurian systems
- Cambrian defined by the rocks it overlaid
- Silurian defined by fossil contents
What is Chronostratigraphy?
The element of stratigraphy that deals with the relative time relations and ages of rock bodies.