Flashcards
Rocks pt 2
Cards in this deck (16)
- 1What is stratigraphy?The study of layered rocks.
- 2What is correlation?Tracing beds of the same age from place to place.
Easy over short distances. - 3What are conformities?Contacts (changes in rock type) representing continuous deposition of sediments.
- 4What are unconformities?Surfaces of erosion and/or non-deposition of sediments (missing time).
- 5What are disconformities?Sedimentary rocks over sedimentary rocks with obvious erosional relief
- 6What is a paraconformity?Sedimentary rocks over sedimentary rocks with NO obvious erosional relief. (horizontal contact)
- 7What is a nonconformity?Sedimentary rocks OVER igneous or metamorphic rocks.
- 8What is an angular unconformity?Flat sedimentary rocks over tilted or folded sedimentary rocks.
- 9What are facies?Def 1: All the characteristics of a rock.
Def 2: The environment in which a rock formed. - 10What is Walther's Law?Facies that are now in vertical succession were originally next to each other.
- 11What is transgression?Sea level is slowly rising
(hot) - 12What is regression?Sea level is slowly lowering
(cool) - 13What are two important factors that result in sea level change?1: Climate change = increases volume of water.
2: Tectonic divergence = changes in he volume of ocean basins.
(rapid seafloor spreading = higher seafloor) - 14What is a formation?The fundamental unit of stratigraphy:
Rock unit of distinctive lithology that's thick enough to be mapped. - 15What are members?Subdivisions of formations.
- 16What are groups?Unit with 2 or more formations.