Chapter 11 - ESC1000 Flashcards
(60 cards)
What is the principle of uniformitarianism?
Concept that the processes that have shaped the Earth in the past are essentially the same as those operating today.
What is catastrophism?
Concept that Earth was shaped by catastrophic events of a short-term nature.
What is numerical dating?
Date that specifies the actual number of years that have passed since the event occurred.
What is relative dating?
Date that results from placing the rocks in their proper sequence or order to determine the chronological order of events.
Who was James Hutton?
Famous Scottish physician from the 1700s who published his Theory of Earth that puts forward the fundamental principle of uniformitarianism.
Who was James Ussher?
Anglican archbishop from the mid 1600s who constructed a chronology of human and Earth history based on the bible in which he determined that Earth was only a few thousand years old.
Explain the difference between catastrophism and uniformitarianism.
Catastrophism views the processes that shape the Earth as short-term events while uniformitarianism views the processes that shape the Earth as slow and acting over long spans of time.
List the principles of relative dating.
Superposition, Original Horizontality, Lateral Continuity, Cross-Cutting Relationships, and Inclusions.
What is the principle of superposition?
States that in any undeformed sequence of sedimentary rocks, each bed is older than the one above and younger than the one below.
Who is Nicholas Steno?
Danish geologist from the 1600s that proposed the principles of superposition and original horizontality.
What is the principle of original horizontality?
Principle by which layers of sediment are generally deposited in horizontal position.
What is the principle of lateral continuity?
Principle which states that sedimentary beds originate as continuous layers that extend in all directions until they grade into a different type of sediment or thin out at the edge of a sedimentary basin.
What is the principle of cross-cutting relationships?
Principle which states that a rock or fault is younger than any rock or fault through which it cuts.
What is the principle of inclusion?
Principle which states that the rock mass that provided the inclusion is older than the rock mass containing the inclusion.
What are unconformities?
A surface that represents a break in the rock record, caused by erosion or nondeposition.
What is conformable?
Layers of rock that were deposited without interruption.
List the 3 types of unconformities.
Angular, Disconformity, and Nonconformity.
What is angular unconformity?
Unconformity in which strata below dip at an angle different from that of the beds above.
What does an angular unconformity indicates?
Indicates that during a pause in deposition, a period of deformation (folding or tilting), and erosion occurred.
What is a disconformity?
Is a gap in the rock record that represents a period during which erosion rather than deposition occurred. Beds above and below are parallel.
What is nonconformity?
An unconformity in which older metamorphic or intrusive igneous rocks are overlain by younger sedimentary strata.
How does a nonconformity form?
Older metamorphic and igneous rocks that originate deep below must experience a period of uplift. Once exposed at the surface the rocks are subject to erosion and undergo a renewed period of sedimentation.
What are fossils?
Remains and traces of organisms preserved from the geologic past.
What is paleontology?
Systematic study of the fossils and the history of life on Earth.