principles of historical geology ii historical geology – principles ii
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Principles of Historical Geology II
Historical Geology – Principles II
Unconformity:
a surface between layers of rock
which formed during a
time of erosion or non-deposition
Historical Geology – Principles II
An unconformity:
represents “missing time”
(time without as sedimentary record)
Historical Geology – Principles II
Monday, April 23rd
Construction rained out for 3 weeks
(non-deposition)
Monday, April 23rd
Monday, April 23rd
Wednesday, June 1st
disconformity
1980
1980
30 yrs later: the wall is
demolished, but a foundation
kept for a new wall.
“erosion”
1980
2010disconformity
30 missing yrs
sedimentary rocks
sedimentary rocks
parallel to
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Sedimentary
Sedimentary
erosion
erosion
erosion
Sedimentary
Sedimentary
Grand Canyon
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Devonian Sedimentary
Mississippian Sedimentary
Erosion Surface
sedimentary rocks
non - sedimentary rocks
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Proterozoic Metamorphic
Cambrian Sedimentary
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Cranberry Gneiss1.1 billion yrs old
Unconsolidatedstream gravel1.1 billion yrs old
Nonconformity
Boone CreekRivers St & Varsity Gym
sedimentary rocks
sedimentary rocks
over tilted
Sedimentary
Sedimentary
More Principles
Charles Lyell: Text Book (early 1800's)
"Principles of Geology"
A uniformitarian "how to" book
a classic still in print
Historical Geology – Principles II
More Principles
Inclusion of Components: A body of rock is younger than
a second body from which any
of its pieces are derived.
Historical Geology – Principles II
More Principles
Inclusion of Components:
Le
vin
Fig
. 1
-10
Historical Geology – Principles II
More Principles
Crosscutting Relationships:
Features are younger than the rocks that they transect,
and younger than any other feature they transect.
Historical Geology – Principles II
More Principles
Crosscutting Relationships:faults, igneous intrusions, unconformities
Historical Geology – Principles II
More Principles
Historical Geology – Principles II
Crosscutting Relationships:
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Three Major Rock Types
Igneous:
Metamorphic:
Sedimentary:
Historical Geology – Principles II
Rock Cycle
Review
If you don’t remember the differencebetween a gneiss & a graniteor a slate and a shale...
Review Chapter 2Review specimens in Geology Museum
Historical Geology – Principles II
Unifying Theory
Chemistry: atomic theory
Physics: Newtonian/quantum/unified theory
Biology: evolution - natural selection
Geology: ?
Historical Geology – Principles II
Unifying Theory
Geology: Plate Tectonics
• 1960’s
• community effort
(atypical paradigm shift)
Historical Geology – Principles II
Plate Tectonics: unifying theory of geology
Earth as a System
Earth as a System
Historical Geology – Principles II
Inter-related processes:
• physical
• chemical
• biological
Earth as a System
Historical Geology – Principles II
Inter-related processes:
• physical
• chemical
• biological
Some of themcyclic
Plate tectonics
Water cycle
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Great Barrier Reef