GEOLOGICAL OCEANOGRAPHY

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GEOLOGICAL OCEANOGRAPHY Section II Lecture
10 REEFS THROUGH TIME 20 March 2008
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James (1997) proposed terminology based largely
on trophic status of major contributors
James (1997)
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James (1997)
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Morse Mackenzie (1990)
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(Hubbard in press)
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Processes influencing accretion
(Longman 1981)
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CONDITIONS FAVORING SHALLOW-WATER CORAL-REEF
GROWTH(remember Goldilocks)

• Water temperature 18oltTlt31o C
• Normal marine salinity 32-40o
• Water movement
• too much or too little can be limiting
• Light
• Need light for photosynthesis
• Too much short ? ? photo-oxidative stress
• Limited terrigenous sediment
• Limited nutrient input

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Zooxanthellate-coral reefs occur in regions
influenced by warm currents
(Hubbard in press)
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Effects of wave energy and water transparency on
zonation of Caribbean coral reefs
(Hubbard in press)
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Wave energy vs. hurricane frequency
(Hubbard in press)
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(Longman 1981)
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(Longman 1981)
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(Hubbard in press)
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Effects of relative sea level change

• Stable sea level
• Lateral accretion
• Progradation
• Transgression or subsidence
• Vertical accretion
• Backstepping
• Keep-up (can include progradation)
• Catch-up
• Give-up
• Regression or uplift

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(Longman 1981)
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Schematic section across Great Bahama Bank from a
seismic profile
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(Longman 1981)
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(Hubbard in press)
Buck Island Reef, USVI, accreted and prograded
since initiating 7000 years ago
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Backstepping
(Hubbard in press)
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(Hubbard in press)
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Holocene Rapid Sea-Level Rise Events
Blanchon and Shaw (1995)
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Locker et al. 1996
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Sea level rise as indicated by Acropora palmata
(Hubbard in press)
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Darwin Point
(Hubbard in press)
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Darwins Theory of Atoll Formation
http//en.wikipedia.org/wiki/ImageCoral_atoll_for
mation_animation.gif
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The Voyage of the BEAGLE                        
                                                
                                
Some of Charles Darwins sketches from his book
Coral Reefs
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(No Transcript)
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Selected tropical and non-tropical shelf
carbonates
What happens outside tropical regions?
Flügel (2004)
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James (1997)
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Flügel (2004)
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Pomar (2001)
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Carbonate buildups through time
Stromatolites
(James 1983)
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Biostrome carbonate accumulation that had no
substantial topographic relief

• Bioherm carbonate buildup that had topographic
  relief

(James 1983)
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CONDITIONS ENABLINGREEF GROWTH

• In situ production of skeletal framework and
  sediment exceed rates of erosion, dissolution,
  and input of allochthonous sediment

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Limited relief when forming
Substantial relief when forming
(James 1983)
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Typical reef-related facies
(James 1983)
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(James 1983)
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The actors change but the roles remain the same
R. Ginsburg
(James 1983)
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Types of reef limestones
(James 1983)
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(James 1983)
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Reef environments and facies
(James 1983)
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Stages in carbonate buildups
Buildup
Reef
Reef
Reef mound
Biostrome
(James 1983)
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Types of frame-rimmed platforms may result from
differences in production processes and loci
Pomar (2001)
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Precambrian Stromatolites
Stromatolites
(James 1983)
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Stromatolitic Limestone Siyeh Limestone, Belt
Group Glacier National Park, MT
Stromatolite
10 cm
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Modern analogues
Lake Thetis West Australia
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Limestone Gorge, West Australia
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Columnar stromatolite, Grand Canyon
Displaced block
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Early Paleozoic Bioherms
Stromatolites
(James 1983)
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Lower Cambrian BiohermLabrador, Canada
Archaeocyathid fossils
(James 1983)
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Middle Cambrian Stromatolitic Bioherm, Central
Texas
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Middle Paleozoic Bioherms
Stromatolites
(James 1983)
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Middle Ordovician, Southern Nevada
(James 1983)
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Ordovician - Devonian fauna
http//www.uky.edu/KGS/coal/webfossl/pages/corals.
htm
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Ordovician - Devonian faunaBryozoa
http//www.uky.edu/KGS
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Ordovician - Devonian faunaechinoderms
http//www.uky.edu/KGS
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Ordovician-Devonian Stromatoporoids (fossil
scelerosponges)
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Late Devonian Reefs
Stromatolites
(James 1983)
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Devonian Reef Complex, Winjana Gorge, Canning
Basin, Western Australia
(James 1983)
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Types of frame-rimmed platforms may result from
differences in production processes and loci
Pomar (2001)
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Devonian Reef Complex, Winjana Gorge, Canning
Basin, Western Australia
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Reef facies
Slope facies
Backreef facies
Devonian Reef Complex, Winjana Gorge, Canning
Basin, Western Australia
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Devonian Fossils from Winjana Gorge
Renalcis
Nautiloid
Stromatoporoid
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Late Devonian Mass Extinction
Stromatolites
(James 1983)
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Late Paleozoic Reef Mounds
Stromatolites
(James 1983)
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Early Mississippian Mud MoundMuleshoe, SE New
Mexico
(James 1983)
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Mound facies
Mississippian Mud Mound FossilsMuleshoe, SE New
Mexico
Bryozoan wackestone
Crinoid rudstone
Flank facies
5 cm
(James 1983)
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(James 1983)
Late Pennsylvanian Phylloid Algal Mound, New
Mexico
1 cm
Phylloid Algal Wackestone
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Permian Reef Complex, Carlsbad Caverns National
Park, NM
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Permian Reef Complex, Carlsbad Caverns National
Park, NM
Backreef
Reef
Slope
Basin
Classic prograding reef complex
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(James 1983)
2cm
5cm
10cm
Sponge boundstone
Fusulinid grainstone
Castile Gypsum
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Types of frame-rimmed platforms may result from
differences in production processes and loci
Pomar (2001)
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Permian-Triassic Boundary Mass Extinction Event
Stromatolites
(James 1983)
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Mesozoic Bioherms and Events
Stromatolites
(James 1983)
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Upper Triassic Reef Austrian Alps
(James 1983)
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Upper Triassic Reef Fossils, Austrian Alps
10cm
Coral Framestone
Sphinctozoan sponge encrusting hardground
2cm
(James 1983)
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Lower Jurassic Coral Reef, Atlas Mts., Morocco
(James 1983)
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Reef Core
(James 1983)
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Lower Cretaceous Boquillas Limestone, Big Bend
National Park, Texas
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Upper Cretaceous, Rudist Bioherms, Spanish
Pyrenees
Core
Slope
Core
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Giant rudists
Coral
Rudist thicket
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Interpretation of Upper Cretaceous, Rudist
Bioherms, Spanish Pyrenees
(Skelton and Gili)
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Cretaceous-Tertiary Boundary Mass Extinction
Event
Stromatolites
(James 1983)
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Eocene Carbonate Accumulations,Kef el Gurtom,
Tunisia
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Eocene larger foraminiferal limestones,Tunisia
Foram wackestone with burrow
Foram rudstone
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Location Map of ODP Leg 194
Drilled two Miocene carbonate platforms
NMP Northern Marion Platform SMP Southern
Marion Platform
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(No Transcript)
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1mm
Larger foram
Bryozoa
1193a, 12X, 1, 6
gt11.9 Ma
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(No Transcript)
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1196a, 19R, 1,1
1mm
Red algae
1196a, 16R, 1, 33
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Thin sections of reef facies, Marion Plateau,
Australia, Miocene
Larger forams and Halimeda
Coral and larger forams
1 mm
ODP Leg 194
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Reefspurs, Miocene, Mallorca, Spain
(James 1983)
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Pomar (2001)
Rhodolith facies
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Windley Key Park, Florida Keys, Key Largo
Limestone, Pleistocene
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Modern Florida Keys Reefs
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Carbonate buildups through time
Stromatolites
(James 1983)
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Mass Extinction Events

• Causes
• Not well known
• K-T Boundary probably combination of extensive
  vulcanism and meteor impact
• Consequences
• World-wide carbonate depositional hiatus
• Shallow-water carbonate-producing and associated
  communities suffer very high extinction rates
• Generally set back to stromatolite or mud-mound
  stages
• Require 10s of millions of years to re-establish
  high diversities

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Neritic lime-mud factory
(Pomar Hallock 2008)
Benthic automicrite factory
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Carbonate Shelves

• Minimal terrigenous influence
• Most are warm-temperate to tropical
• Cold or deep water carbonates occur where
• terrigenous sediments are lacking
• currents sweep away fine sediments and provide
  ample food for non-zooxanthellate producers
• Reefal, skeletal, non-skeletal sediments
• Attached or non-attached
• Rimmed shelves or platforms or ramps
• Most extensive on trailing margins

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Highlights to remember/study(includes
shallow-water carbonates lecture)

• What kinds of organisms produce/influence
  carbonate sediments/sedimentation
• Hermatypic vs. ahermatypic
• Basic reef types
• Including Darwins theory of atoll formation
• Conditions favoring carbonate sedimentation
• Major types of carbonate buildups and facies
• Basic overview of geologic time
• Major reef builders
• Major Phaerozoicmass extinction events