Chapter 8 Part 1 Flashcards
John Wesley Powell
led expedition on Colorado River through Grand Canyon in 1869
James Ussher
-wrote comprehensive history from creation to 70 AD (fall of Jerusalem)
James Ussher wrote
“Annals of the World” 1654
Dates in James Ussher’s history
- 4004 BC–>creation week
- 2348-7 BC–>Noah’s Flood
- 1921 BC–>call of Abram
- 4 BC–>Birth of Jesus Christ
1611
King James Bible published
“Young-earth” creationism (YEC)
- earth is thousands of years old
- Noah’s flood explains rocks and fossils
Nico Steno
young-earth creationist that
- established early rules for interpreting sedimentary rocks
- fossils are former living organisms
- rocks of the Alps were formed during different stages of the flood (accepted for hundreds of years but challenged in late 1700s)
challenges to rocks of the Alps being formed during different stages of the flood
1) Were all rocks and fossils formed by Noah’s flood?
2) Was Ussher’s date of creation correct?
tenets of catastrophism
1) Earth is ancient
2) Earth’s geology was formed by many catastrophes over time (Noah’s flood is only the most recent catastrophe)
- God created whole new species and ecosystems after each catastrophe
Novel interpretations of Genesis
Day-age theory and gap theory
day-age theory
the word ‘day’ should be reinterpreted to mean vast periods of time
gap theory
there is a gap between Genesis 1 and 2 that God didn’t document where dinosaurs existed
Georges Cuvier
“spokesperson”/”architect” for catastrophism
James Hutton
- uniformitarianism
- wrote “Theory of the Earth”
Charles Lyell
- uniformitarianism
- wrote “Principles of Geology” 1830-33
uniformitarianism “motto”
“The present is the key to the past”
actualism
- descension from uniformitarianism
- the events and structures of the geologic record were caused by processes much the same as those seen today
2 Peter 3
there are events that are unlike anything we have/are/will experience
2 types of geologic dating
- relative dating
- “absolute” dating
relative dating
placing rocks and geologic events in sequence and order
law of original horizontality
sediment (or ash falls and lava flows) tend to be deposited in flat sheets in a horizontal position
law of superposition
for sediments, older sediments are at the bottom and younger sediments are at the top
principal of cross-cutting relations
younger features will cut across older features (ex. fault, dikes (volcanic pipes)
rule of inclusions
if a rock (A) contains pieces of another rock (B), then rock (B) must be older than rock (A)
unconformities
surface that represents a break in time (due to non-deposition or erosion) during sedimentation
uniformitarianism
the physical, chemical, and biological laws that operate today have also operated in the geologic past
Can relative dating tell us how long ago something took place?
No, it only tells us that it followed one event and preceded another
conformable
when we observe layers of rock that have been deposited essentially without interruption
Does any place on earth have completely conformable strata?
no
unconformities represent
significant geologic events in Earth history
angular conformity
- most easily recognized
- consists of tilted or folded sedimentary rocks that are overlain by younger, more flat-laying strata
disconformities
- more common but usually less conspicuous
- strata on either side are essentially parallel
nonconformity
-separates older metamorphic or intrusive igneous rocks from younger sedimentary strata
correlation
the process of linking rock units over distances in which they are unseen
2 types of correlation
physical and temporal
physical correlation
same type of rocks/minerals
temporal correlation
same age in time
Correlation over short distances is often achieved by noting
the position of a rock layer in a sequence of strata
fossil
any evidence of past life in the geologic record
paleontology
the scientific study of fossils that blends geology and biology
body fossils
hard parts of an organism
petrified
when silica invades cavities and pores of the original structure
mold
when a structure is buried in sediment and then dissolved by underground water
replacement
cell walls are removed and replaced with mineral matter
casts
when hollow spaces are filled with mineral matter
carbonization
when fine sediment encases the remains of an organism and leaves a residue of carbon
impression
a replica of the surface
principle of fossil succession
fossil organism succeed one another in a definite and determinable order, and any time period can be recognized by its fossil content
index fossils
widespread geographically and are limited to a short span of geologic time
fossil assemblages
groups of fossils that determine the age of a bed
fossil types
- petrification
- tracks/trails
- imprints/casts/molds
- amber
