Stratigraphy
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DEFINITION OF STRATIGRAPHY
1. Branch of geology that deals with definition &
description of major & minor natural division of rocks...
w/ the interpretation of their significance in geologic
history.
2. Specifically, the geologic study of the form,
arrangement, geographic distribution, chronological
succession, classification & esp. correlation and mutual
relationships of rock strata in normal sequence.
3. It involves interpretation of these features of rock
strata in terms of origin, occurrence, environment,
thickness, lithology, composition, fossil content, age,
history, paleogeography etc
http://www.ags.gov.ab.ca/publications/wcsb_atlas/a_ch11/ch_11_f.html
http://web.wm.edu/geology/virginia/provinces/Blueridge/blue_ridge_strat.html?svr=www
Introduction
A.
Beginning(~1500AD) da Vinci
saw fossils in rks of
Italian Apennines
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Concluded fossils
once living marine
organisms
http://www.ucmp.berkeley.edu/history/vinci.htm
Introduction
B.
Steno- 1669important
contributor
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Principle of Original
Horizontality
Principle of
Superposition
Principle of Lateral
Continuity
http://www.ucmp.berkeley.edu/history/steno.html
Steno Principles
http://itc.gsw.edu/faculty/bcarter/histgeol/time/latcont.htm
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Lateral Continuity
Superposition
Original Horizontality
Development of Sed Strat as
Science
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Organization of sed
rocks—Arduino
(1714-15) divided
rocks
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Primary Mtnsmetallic ores no
fossils
Secondary MtnsStratified, lithified,
fossiliferous, no
fossils
Tertiary low MtnsFossiliferous,
unconsolidated
gravels, sands
clay, volcanics
AlluviumSediment washed
down from mtns
http://www.quaternary.stratigraphy.org.uk/about/history.html
Development of Sed Strat as Science
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Geologic Cycle and
Uniformitarianism
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James Hutton (17271797)-Scottish
Physician, farmer
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Noted cyclicity to
earth’s behavior
Uplift, erosion,
transport,
deposition
Established Principle
of Uniformitarianism
or Actualism
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present key to
past but rates
change and
catastrophes
occur
http://www.ucmp.berkeley.edu/history/hutton.htm
Development of Sed Strat as
Science
gsahist.org
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Birth of Biostratigraphy &
Stratigraphic Correlation
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William Smith(1769-1839)-English
surveyor, engineer
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“father” of biostratigraphy
Canal builder noted relationship of
fossils & rocks
Established law of faunal
succession—fossils succeed each
other in organized & recognizable
fashion
Produced first geologic map
Birth of Biostratigraphy & Stratigraphic Correlation
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D’Orbigny (1842)developed biologic
stage for rock
division
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strata
systematically
follow each other
with characteristic
fossil assemblage
Oppel (1856)developed biologic
zone
Rocks deposited
during existence of
specific fossil
 Zones based of
first appearance of
last appearance of
organisms
 Zones could be
correlated
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Oppel Zones
Development of Sed Strat as Science
Petrographic microscope
development
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Geologic RevolutionSeafloor Spreading and
Plate Tectonics
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Sorby began microscopic
study of rocks
Led to description and
systematic study of rocks
1950-1960s- Renaissance
period
More funds, more
geophysical exploration,
Deep Sea Drilling Project
More oil exploration
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New Tools
 Magnetic and Seismic
Surveying
 Identification of
normal/reverse
periods led to
magnetostratigraphy
 Seismic surveying
could identify units
and unconformities,
packages of related
rocks
 Isotope stratigraphy
 Use carbon and
oxygen isotopes to
correlate units
petroleum-gas.blogspot.com
http://www2.ocean.washington.edu/oc540/lec01-28
Magnetostratigraphy
sp.lyellcollection.org
Seismic Stratigraphy
www-odp.tamu.edu
Development of Sed Strat as Science
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Sedimentary
Rocks and Earth
History
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Paleoclimate
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study of ancient
climate
Development of Sed Strat as Science
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Sedimentary
Rocks and Earth
History
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Paleogeography
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reconstruction
of area for
given time in
past
http://jan.ucc.nau.edu/~rcb7
Wiley.com
•
Development of Sed Strat as Science
Sedimentary
Rocks and
Earth History
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Paleoecology &
Evolution
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studies
relationships
between
ancient
organisms &
their
environments
http://scienceblogs.com/laelaps/Futalognkosaurus%2Bmural.
jpg
Development of Sed Strat as Science
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Sedimentary Rocks
and Earth History
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Paleoceanography
& Ancient
Atmosphere
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Composition of
ancient oceans and
atmosphere using
isotopes
http://www.jamstec.go.jp/rigc/j/ebcrp/paleo/