Dynamic Interior L1 Flashcards
What is a sedimentary rock?
Rocks made up of minerals eroded from pre-existing rocks, fossils, or chemical precipitates.
What temperatures are sedimentary rocks stable at?
Low temperatures
What is a metamorphic rock?
Rocks formed by the heating and burying of pre-existing rocks.
What is an igneous rock?
Rocks formed by crystallising minerals and glass from magma.
What conditions are igneous rocks stable?
High temperature and pressure
Who formulated the theory of uniformitarianism?
James Hutton
Who formulated the theory of uniformitarianism?
James Hutton
Outline the basis of the theory of uniformitarianism?
The theory holds that the Earth was shaped by the same processes that can be observed operating today slowly.
What are the 4 stages of uniformitarianism?
1) Sedimentation
2) Deformation
3) Erosion
4 Renewed sedimentation
What is an unconformity?
A boundary between rocks representing a break in time caused by a period of erosion of deformed rocks followed by the deposition of new sediments
What is a conglomerate?
A sedimentary rock which has a fine-grained matrix containing a mixture of class.
What are the 4 laws put forward by Charles Lyell?
1) Law of superposition
2) Law of horizontality
3) Law of lateral continuity
4) Law of cross-cutting relationships
What is the law of superposition?
Laid down sediments are younger at the top and older at the bottom
What is the law of horizontality?
Sediments are originally laid down horizontally
What is an example of lateral continuity and how does it occur?
The sequence of rocks on one side of a valley can most likely be followed across the other side of the valley. This occurs as a result of erosion separating a sequence of rocks.
What is the law of cross-cutting relationships?
A rock that is cross-cut is older than the rock that cross cuts it.
What is stratigraphy?
A branch of geology that studies the layering of rocks and relates them to a geological time scale.
What are the 6 main types of stratigraphy and what do they relate to?
1) Lithostratigraphy (rock types)
2) Biostratigraphy (fossils)
3) Magnetic stratigraphy (magnetic field changes)
4) Isotopic stratigraphy (isotope composition)
5) Astronomical chronometry (obliquity, precession, eccentricity)
6) Radiometric chronometry (radioactive decay)
