Whitings

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Whitings Source of Black Gold?
-UAE Algal mats lime mudsA link to Middle
East carbonate source rock potential

• C.G.St.C. Kendall, Xavier Jenson Eugene Shinn

Departments of Geological Sciences, University
of South Carolina, Jackson School of Geology,
University of Texas Austin, and Marine Science
Center, University of South Florida
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Outline of Presentation

• The Hypothesis
• Overview of Arabian Gulf Reserves
• Geological setting of Arabian Gulf
• Modern lime mud cyanobacteria generation of
  Arabian Gulf
• Bahamian Whitings Productivity, Sequestration
  Organic Matter
• Geological setting of Arabian Gulf Oil Fields
  tie of hydrocarbon sequestered cyanobacterial
  remains in geologic section
• Significance of Russian source rock study
• Conclusions

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Hypothesis

• Significant Holocene accumulations of
  cyanobacteria lime mud in Arabian Gulf axis
  tidal zones
• These sediments have source rock potential
• Similar sediments have accumulated since Triassic
• Ancient carbonate muds are source of significant
  petroleum reserves of Arabian Gulf region
• The present is the key to the past!

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Current Middle East Reserves
Crude Oil(BB) - Natural Gas (TCF)

• Saudi Arabia 263.5 bbls 204.5 Tcf 8 Years
• Iraq 112 bbls 109 Tcf
• UAE 97.8bbls 212 Tcf
• Kuwait 96.5 bbls 52.7Tcf
• Iran 89.7 bbls 812.3Tcf
• Oman 5.3 bbls 28.4 Tcf
• Yemen 4.0 bbls 16.9 Tcf
• Qatar 3.7 bbls 300.0 Tcf
• Syria 2.5 bbls 8.5 Tcf
• Bahrain 0.1 bbls 3.9 Tcf
• TOTAL 675.1 bbls 1,748.2 Tcf

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MIDDLE EAST FIELDS
Location of Middle Eastern Oil Fields
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Oil Production - Arabian Gulf

• Productive hydrocarbon section older to West
  Paleozoic younger at Arabian Gulf Coast
  Mesozoic youngest in East in Zagros Mts
  Upper Tertiary.
• West to East production includes
• Infra-Cambrian Salt
• Silurian and Ordovician clastics Unaizah
• Permian clastics carbonates Khuff
• Upper Jurassic Carbonates - Arab Tuwaik Mt Grp
• Lwr Cretaceous Carbonates Shuaiba Thammama
• Middle Cretaceous Mishrif
• Tertiary - Asmari
• Mesozoic through Tertiary-Lime Mud Source

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Proposed Concept

• Arabian Gulf Holocene cyanobacteria mud
  accumulations significant in axis tidal zones
• These sediments have source rocks potential
• 4000 meters of similar sediments have accumulated
  here since Triassic
• Sequestered ancient carbonate muds are source of
  the significant petroleum reserves of Arabian
  Gulf region
• The present is the key to the past!

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Structural Provinces - Arabian Gulf
Zagros Fold Mts
Pre-Cambrian Shield
Mesozoic to Tertiary Foreland Basin
4,000 meters of Mesozoic to Tertiary Sediment
sequestered in Foreland Basin!
NASA Image
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Analysis of Crude Oils find Alkanes Isoprenoids

• The alkane/acyclic isoprenoid fraction is the
  main constituent of most crude oils
• A large number of crude oils and rock extracts
  from Timan-Pechora basin (Russia) suggest this
  fraction is direct product of liquefaction of
  biological debris preserved essentially unaltered
  till oil generation.
• Result is the primary biological provenance of
  this fraction is preserved in the oil fraction.

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Hydrocarbon Source

• Collister, Ehrlich, Mango, Johnson (AAPG,
  2004) propose primary organic materials convert
  to oil as dispersed alkanes isoprenoids in
  rocks
• Low TOC source or undermature rocks generate
  significant oil if source carries sufficient
  special kerogen derived from biological membranes
  is unchanged till liquefaction
• Observations experiments, mostly French labs,
  show resistant organic membranes in form of
  biopolymers play this role.
• Stable over a large range of conditions, survive
  early secondary bacterial attack late-stage
  breakdown with increasing thermal stress.

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Evidence

• Significant Holocene accumulations of
  cyanobacteria lime mud in Arabian Gulf axis
  tidal zones
• These sediments have source rocks potential
• Similar sediments have accumulated since Triassic
• Ancient carbonate muds are source of significant
  petroleum reserves of Arabian Gulf region
• The present is the key to the past!

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Carbonate Provinces - Arabian Gulf
Basin
Ramp
Open Shelf
Restricted Shelf
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Dust and Whiting response
Satellite scenes SW, to West coast of Arabian
Gulf 12 July 2006, MODIS Rapid Response system
site, Nasa http//rapidfire.sci.gsfc.nasa.gov
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Weather Station Data
Temperatures - pink MPH windspeed -
black. Windspeeds over 25mph coincide with
regional "Whiting" blooms.
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Arabian Gulf Factory producing carbonates
storing products of cyanobacteria since Permian
NASA Image
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A big day for a bloom!!
Organics in the Gulf!
Nasa Image
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Whitings common to-day and common back in the
Triassic!
Organics in the Gulf!
Nasa Image
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Wells and Illling - 1965

• Among 1st to report Whitings offshore from
  Qatar precipitated in Persian Gulf.
• Ascribed whitings to CO2 removal by
  photosynthesis of phytoplankton.
• Groot (1964) lab analysis of suspended sediment
  offshore was 70 Aragonite, 10 Calcite, 15 Mg
  Calcite, 5 Quartz 5 Dolomites.
• Lab experiments used NaCO3 to remove CO2 pptated
  aragonite from Gulf, but rates did not match
  instantaneous formation of Whitings but took 2
  to three weeks.

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Local Whiting Occurrences!
NASA satellite scene with very localized
diminished Whitings off UAE on Pearl Bank,
offshore East Qatar, north flank of Bahrain
shoal, and offshore from Saudi/Kuwaiti border
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Persian Gulf Facies Distribution
After Wilkinson Drummond, 2004
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Persian Gulf Mud Distribution
After Wilkinson Drummond, 2004
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Lime Mud Sequestered in Basin Axis Tidal Flats
The mud probably forms less than 1 of sediment
signal since Mesozoic but forms a formidable
source for hydrocarbons of Gulf
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Facies of UAE
Lime muds organics sequestered in axial
trough tidal flats
Axial Muds
Skeletal Sands
Ooid Tidal Deltas
Reefs Coralgal Sands
Pellets Grapestones
Coastal Sabkha
Cyanobacterial mats
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Lime mud organics sequestered in
Mangrove swamp tidal flats
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Shoaling Upward Inner Shelf Cycle
Shoaling Up Cycle
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Abu Dhabi Mud Flats
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Abu Dhabi Mud Flats
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High Intertidal Cyanobacterial Flats
Intertidal Carbonate Flats
Earlier High Energy Beaches
Supratidal Sabkha Evaporites
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Tidal Ponds
Tidal Creek
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Tidal Pond
Tidal Creek Cyanobacterial Megapoygons
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Cyanobacterial Peat
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Crinkled Algal Mat
Gypsum Mush
Cyanobacterial Peat
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SURFACE ANHYDRITE POLYGONS
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Anhydrite
Cyanobacterial Peat
Intertidal Muds
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HALITE POLYGONS
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Washover Sediments
Anhydrite
Cyanobacterial Peat
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MICROTOME OF CYANOBACTERIAL MATS
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Modern Sources of lime mud

• Isolated seas Arabian Gulf
• Wide platforms in nutrient deserts of tropical
  seas Bahamas

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Bahamian Organic Productivity

• Whitings precipitate 1.35 metric tons per year
• 25 of Whiting is organic matter mostly
  cyanobacteria and microalgae
• As much as 1.6 of surface sediment may contain
  organic matter
• Subsurface sediments preserve 1 TOC (up to 4)
• 7Be (half-life 53 days) found in Whitings but
  absent in resuspended bottom sediment

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Bahamas Ocean Drilling Transect
Kramer, Swart, DeCarlo Schosvbo, 2005
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Modern Sources of lime mud

• Isolated seas Arabian Gulf
• Wide platforms in nutrient deserts of tropical
  seas Bahamas

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Whitings
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Whiting
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Aragonite Needles 2.5mm Long 0.25 mm Wide
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Sequestration in Downslope wedge
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Sequestration on Tidal Flat
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Bahamas shoals source of mud
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Rates of Accumulation

• Short-lived isotopes determin accumulation rates
  (Shinn et al., 2000).
• Samples analyzed within 20 days of collection
  using high-resolution gamma ray spectrometer for
  short-lived isotopes Be-7 Th-234 with
  respective half lives of approx. 53 23 days.
• Active billowing Whitings had Be-7 Th 234 but
  bottom sediment depleted.
• None of bottom sediment stirred by storms
  contained short-lived isotopes.
• Radiogenic elements adsorbed on sediment surface,
  or if epitaxial growth occurred, these
  short-lived isotopes would be present.

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Bahamian Whitings Instant Precipitates

• Whitings vivid white while water outside them is
  clear!
• Instantaneous chemical /or biochemical aragonite
  precipitates.
• Many Whitings drift back forth with tides over
  time continually raining sediment to bottom with
  no documented dispersal or end.
• Wane in intensity at slack tide to strengthen
  when tide reverses.
• Cloud (1961) followed a single Whiting for 48
  hours while Shinn et al. (1989) followed Whitings
  for 24 hrs.
• Some persisted for 24 hrs over hard pellet sands
  with no mud stirred into suspension. Shinn et al.
  (1989) returned to same Whitings still drifting
  over pellet sand 2 days later Robbins et al.
  (1997) documented persistence from satellite
  images.
• Artificial Whitings of stirred up bottom settled
  within 6 hours
• Nearby natural Whitings persisted and did not
  dissipate
• Whiting water pumped to settling tanks aboard
  boat settled in 6 hrs.

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Whiting Mud Sequestration

• Hurricanes winter storms export vast quantities
  of lime mud over bank edge.
• 7 weeks after Hurricane Andrew (1992), lime mud
  collected as layers up to 5 cm thick over shallow
  ooid sands near bank edge (Shinn et al., 1993).
  Layers from slurries of lime mud exiting bank to
  Florida Straits Tongue of Ocean.
• An up to 90m thick wedge of Holocene sediment at
  base of Bahama Bank slope (Wilber et al.,1990)
  represents 40 to 80 by volume of mud presently
  sequestered for entire bank.
• Vertical and lateral progradation rate of wedge
  is 11-15 m/ka and 80-110 m/ka, respectively
  (Wilber et al., 1990). Measures amount
  accumulated during last 6-8 ka and does not
  consider Whiting mud carried northward in Gulf
  Stream to distant locations and/or to
  dissolution.
• Ball et al. (1967) and Perkins and Enos (1968)
  report significant off-bank sediment transport in
  Florida following Hurricanes Donna and Betsy.
  Similar observations made and photographed in
  Florida by Shinn following Hurricane Andrew in
  1992.
• Lime mud-laden sediment continues to spill off
  the platform for weeks following a hurricane.
  The Bahamian Bank has been submerged for the past
  6-8 ka and is affected by a hurricane every 6 to
  10 years. Overproduction, possibly far greater
  than 280, is necessary to account for what is
  presently on the bank.

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Organic Matter

• Phytoplankton nucleae are cores to cells
• Viable phytoplankton cyanobacterial cells in
  Whitings not observed in bottom sediment -
  deteriorate quickly after deposition (Robbins and
  Blackwelder, 1992) .
• Aragonite needles adher to surface of living
  planktonic cyanobacteria indicates rapid
  precipitation within water column (Robbins
  Blackwelder, 1992 Yates Robbins, 1998 1999
  2001).
• 25 of the 1.3 million metric tons ppted
  suspended each year in Bahamas is organic matter,
  dropping to 1.8 of surface sediment. .
• Bahamian Bank Whitings associated organic
  matter cover more limited areas swept off bank
  into deep water. Cores through Neogene western
  platform slope sediments preserve 1 TOC up to 4
  (Kramer, Swart.

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Bahamas Morphology
Rim
Basin
Restricted Shelf
Open Shelf
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Carbonate Mud Settings

• Carbonate muds common through earth history
• Carbonates signaled by thick sections adjacent to
  margins of recently pulled apart continental
  plates /or in compressional terrains of
  colliding margins
• Carbonate muds collect in
• Lower portions of updip shallow water cycles
• Lower portions of downdip restricted basins
  basin slopes

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Organic matter lt1 weight of Holocene tidal
flats axial trough !
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Carbonate Mud Accumulation Sites of Ancient
Arabian

• Late Paleozoic to Early Mesozoic behind
  Structural Depositional Barriers
• Punctuated by limited access to sea repeated
  arid climatic events favoring cyanobacterial
  preservation
• Now trapped beneath Arabian Gulf

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Hydrocarbon Source, Seal, Reservoir

• Source Rocks
• Permian Khuff - Saudi Arabia
• Lw Jurassic Tuwaiq Mt. Group - Saudi Arabia
• Lw Cretaceous Maudud Fm. of UAE
• Seals
• Usually with playa and sabkha evaporites
• Reservoirs
• Deep Ghawar
• Berri, Ghawar
• Zakum Field, UAE Thamama I, II, and III, Shaybah
• Mishrif
• Asmari

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Arabian Gulf Basin

• Traces complex history of plate tectonic
  sedimentary fill
• Pre Cambrian to Infra-Cambrian - Continental
  interior
• Silurian and Ordovician clastics Continental
  interior
• Permian clastics carbonates Trailing margin
• Upper Jurassic carbonates Trailing margin
• Lower Cretaceous carbonates Trailing margin
• Middle Cretaceous Compression Zagros Mts
  initiated
• Tertiary carbonates clastics - Compressional
  margin

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Evolution of Arabian Gulf
Foreland Basin
Compression Foreland Basin
Extensional margin
Extensional margin
Interior Sag
After Kingston et al, 1983
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Hydrocarbon Production in Arabian
plate Stratigraphic section - Section
represents approx 2,438.5m in 200
my - Accumulation Rate 1.22 mm per 1 Ky
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Lime Source
PERMIAN KHUFF FM DEPOSITIONAL SETTNG (Al-Jallal,
1995)
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Restricted Entrance To Sea
Structural Depositional Barrier over Hercynian
Horst Blocks
Permian Khuff Saudi Arabia Oman UAE
Arid Tropics Air System
Wide Shadow from Adjacent Continents
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WORLDS SOURCE ROCKS
Carbonate Mud Source Rocks
After Baum, Kendall
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Geological Setting of Jurassic Oil
Seal
Seal
Reservoir
Reservoir
IntrashelfBasin
IntrashelfBasin
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Lime Source
GOTNIAN DEPOSITIONAL SETTING (Al-Sharhan
Kendall, 1986)
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Lime Source
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Restricted Entrance To Sea
Upper Jurassic Saudi Arabia Kuwait, Iran UAE
Depositional Barrier over Hercynian Horst Blocks
Tropical Air System !
Wide Shadow from Adjacent Continents
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After Dennis Tassa
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Zagros Fold Mountains - Iran
NASA Image
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Lower Cretaceous
Stratigraphic cross-section of Cretaceous
Eastern Arabia (Alsharhan Nairn 1986)
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Tertiary
Lime Source
Stratigraphic cross-section of Neogene Arabian
Gulf (Alsharhan Nairn 1986)
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From International Petroleum Encyclopedia
Lime Source
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ORGANIC MATTER HYPOTHESIS

• The Arabian Gulf a sink of organic matter since
  Triassic
• As with modern Gulf much of this organic matter
  related to multiple organic blooms through
  geological time
• Organic matter trapped in intertidal flat
  basinal muds
• Dispersed organic matter in form of biological
  membranes, have simple chemical composition
  structure, so liquefy at a threshold
  temperature do not require time temperature
  history for maturation.
• A burst of oil generation produces transient
  overpressures resulting in liberation of oil by
  microfracturing and long-range migration through
  the resulting fractures.
• This ensures that large volumes of oil could be
  generated over a short time.

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CONCLUSIONS

• Arabian Gulf Holocene cyanobacteria mud
  accumulations significant in axis tidal zones
• These sediments have source rocks potential
• Similar sediments accumulated since Triassic
• These ancient carbonate muds are source of the
  significant petroleum reserves of Arabian Gulf
  region
• The present is the key to the past!

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Now to lunch!
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West of Dhabaiya Mangrove Swamp
Holocene tidal flats are sequestering gt1 of
weight as organic matter!
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Bahamas -Deep water of marginal zone-Shallow t
idal flats
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Bahamas
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Bahamas-Mud transportedby hurricanessettle
in highenergychannels
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Bahamas Shoals are a source of mud!
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Bahamas shoals source of mud
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Bahamas shoals source of mud
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Bahamas shoals source of mud
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Bahamas shoals source of mud
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Bahamas shoals source of mud
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Bahamas shoals source of mud
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Bahamas shoals source of mud
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Bahamas shoals source of mud
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Bahamas shoals source of mud
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Appalachians Ordovician Isolated Foreland Basin
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AppalachiansOrdovician
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Appalachians - Ordovician
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Appalachians - Ordovician
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Appalachians - Ordovician
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Appalachians - Ordovician
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Appalachians - Ordovician
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Appalachians Ordovician
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Appalachians - Ordovician
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Appalachians - Ordovician
deepening up from grains to mud
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Appalachians - Ordovician
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Appalachians Ordovician
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Murray Basin
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Murray Basin
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Lime muds organics sequestered in axial
trough tidal flats
Ooid Tidal Deltas
Skeletal Sands
Reefs Coralgal Sands
Pellets Grapestones
Coastal Sabkha
Cyanobacterial mats
Cyanobacterial mats
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Lime mud organics sequestered in
Mangrove swamp tidal flats
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Intertidal Sand Mud Flats
Tidal Channels
Hardgrounds
Beach Ridges
Cyanobacterial Mats
Sabkha
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Whitings
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Geologic Cross-Section - Arabian Gulf
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Lime Source
Gas
Paleozoic Stratigraphic Column Arabia
Gas
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Jurassic Formations of Arabia