Earth Science - chapter 5

Two Geologist stories

Old-Earth and Young Earth

Rubik's Earth model

tectonic plates; supercontinents

pangea

lost one; earth's surface began as one large continent

Ice ages

glacial periods (5)

glacier

mass of ice

last glacial period

ended about 10,000 years ago

geologic column theory

column of rock strata tells the history of the earth

absolute age

fixed age based on nuclear changes

relative date

giving an age based on the geologic column

principle of superposition

older layers are on the bottom of geologic column

stratography

study of rock layers and their relationships; use of index fossils

paleontologists

scientists who study fossils

Old-Earth problems

wandering continents; magnetic crystal directions
Ice Ages
Radiometric dating
Fossil dating - big problems with interpretation

Young-Earth theory

The Flood

history prior to the flood

9 generations from Adam; world went from perfect to very sinful

Details of the Flood story

break up of Earth's crust; rain fell 40 days and nights

evaporation after flood

aided by winds

Ark rested

Ararat; 150 days after flood began

length of time Noah was on the Ark

year

weather changes

result of the flood

The Ice Age - Onset

lava warming up the ocean which sped up evaporation; great amounts of volcanic dust

The Ice Age - Fading

Arctic ice cap forms as oceans cool

Diluvial (flood) geologic column

original continent foundation was granite; soils present; five periods of earth's history

Name the five periods of earth's history

1. The Creation Event
2. The Lost World Era
3. The Flood Event
4. The New-World Era
5. Recent sediments (local flooding)

Tectonics

agent of change

Geosyncline Theory

old earth theory; a long trough in the surface of the earth where sediments and deposits collect; sediment was pushed upward forming a mountain; does not explain folding or fault-block mountains

Continental Drift

Alfred Wegener, continental displacement theory: pangea broke apart and drifted over earth's surface to where continents are today

problems with continental drift theory

could not explain how entire continents could move through ocean crust

Sea-floor spreading

old earth theory; formation of new ocean crust at mid-ocean ridge

mid-ocean ridges

found during WW2

subduction

movement of oceanic plates under the continental plates

tectonic plates

sections of the earth's crust that move

two types of tectonic plates

continental and oceanic

number of tectonic plates

7 major plates
7 minor plates
various smaller plates

plate tectonics theory

uniformitarian theory that the continents drifted and are continuing to drift today

Flood and Plate Tectonics

Young-Earth story disagrees with the WHEN and HOW of Old-Earth

catastrophic plate tectonics

states that the continents were spread apart during a short period of time; catastrophic event (flood) and its aftermath

John Baumgardner

geophysicist - studies the way the earth moves

Problems with Tectonics

Mid-Atlantic Ridge
amount of heat
we really don't know how plate tectonics occurred