Title: Whitings
1Whitings 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
2Outline 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
3Hypothesis
- 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!
4Current 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
5MIDDLE EAST FIELDS
Location of Middle Eastern Oil Fields
6Oil 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
7Proposed 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!
8Structural 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
9Analysis 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.
10Hydrocarbon 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.
11Evidence
- 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!
12Carbonate Provinces - Arabian Gulf
Basin
Ramp
Open Shelf
Restricted Shelf
13Dust 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
14Weather Station Data
Temperatures - pink MPH windspeed -
black. Windspeeds over 25mph coincide with
regional "Whiting" blooms.
15Arabian Gulf Factory producing carbonates
storing products of cyanobacteria since Permian
NASA Image
16A big day for a bloom!!
Organics in the Gulf!
Nasa Image
17Whitings common to-day and common back in the
Triassic!
Organics in the Gulf!
Nasa Image
18Wells 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.
19Local 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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21Persian Gulf Facies Distribution
After Wilkinson Drummond, 2004
22Persian Gulf Mud Distribution
After Wilkinson Drummond, 2004
23Lime 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
24Facies 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
25Lime mud organics sequestered in
Mangrove swamp tidal flats
26Shoaling Upward Inner Shelf Cycle
Shoaling Up Cycle
27Abu Dhabi Mud Flats
28Abu Dhabi Mud Flats
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30High Intertidal Cyanobacterial Flats
Intertidal Carbonate Flats
Earlier High Energy Beaches
Supratidal Sabkha Evaporites
31 32Tidal Ponds
Tidal Creek
33Tidal Pond
Tidal Creek Cyanobacterial Megapoygons
34Cyanobacterial Peat
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36Crinkled Algal Mat
Gypsum Mush
Cyanobacterial Peat
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38SURFACE ANHYDRITE POLYGONS
39Anhydrite
Cyanobacterial Peat
Intertidal Muds
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41HALITE POLYGONS
42Washover Sediments
Anhydrite
Cyanobacterial Peat
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44MICROTOME OF CYANOBACTERIAL MATS
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47Modern Sources of lime mud
- Isolated seas Arabian Gulf
- Wide platforms in nutrient deserts of tropical
seas Bahamas
48Bahamian 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
49Bahamas Ocean Drilling Transect
Kramer, Swart, DeCarlo Schosvbo, 2005
50Modern Sources of lime mud
- Isolated seas Arabian Gulf
- Wide platforms in nutrient deserts of tropical
seas Bahamas
51Whitings
52Whiting
53Aragonite Needles 2.5mm Long 0.25 mm Wide
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55Sequestration in Downslope wedge
56Sequestration on Tidal Flat
57Bahamas shoals source of mud
58Rates 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.
59Bahamian 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.
60Whiting 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.
61Organic 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.
62Bahamas Morphology
Rim
Basin
Restricted Shelf
Open Shelf
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64Carbonate 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
65Organic matter lt1 weight of Holocene tidal
flats axial trough !
66Carbonate 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
67Hydrocarbon 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
68Arabian 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
69Evolution of Arabian Gulf
Foreland Basin
Compression Foreland Basin
Extensional margin
Extensional margin
Interior Sag
After Kingston et al, 1983
70Hydrocarbon Production in Arabian
plate Stratigraphic section - Section
represents approx 2,438.5m in 200
my - Accumulation Rate 1.22 mm per 1 Ky
71Lime Source
PERMIAN KHUFF FM DEPOSITIONAL SETTNG (Al-Jallal,
1995)
72Restricted 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
73 WORLDS SOURCE ROCKS
Carbonate Mud Source Rocks
After Baum, Kendall
74Geological Setting of Jurassic Oil
Seal
Seal
Reservoir
Reservoir
IntrashelfBasin
IntrashelfBasin
75Lime Source
GOTNIAN DEPOSITIONAL SETTING (Al-Sharhan
Kendall, 1986)
76Lime Source
77Restricted Entrance To Sea
Upper Jurassic Saudi Arabia Kuwait, Iran UAE
Depositional Barrier over Hercynian Horst Blocks
Tropical Air System !
Wide Shadow from Adjacent Continents
78After Dennis Tassa
79Zagros Fold Mountains - Iran
NASA Image
80Lower Cretaceous
Stratigraphic cross-section of Cretaceous
Eastern Arabia (Alsharhan Nairn 1986)
81Tertiary
Lime Source
Stratigraphic cross-section of Neogene Arabian
Gulf (Alsharhan Nairn 1986)
82From International Petroleum Encyclopedia
Lime Source
83ORGANIC 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.
84CONCLUSIONS
- 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!
85Now to lunch!
86West of Dhabaiya Mangrove Swamp
Holocene tidal flats are sequestering gt1 of
weight as organic matter!
87Bahamas -Deep water of marginal zone-Shallow t
idal flats
88Bahamas
89Bahamas-Mud transportedby hurricanessettle
in highenergychannels
90Bahamas Shoals are a source of mud!
91Bahamas shoals source of mud
92Bahamas shoals source of mud
93Bahamas shoals source of mud
94Bahamas shoals source of mud
95Bahamas shoals source of mud
96Bahamas shoals source of mud
97Bahamas shoals source of mud
98Bahamas shoals source of mud
99Bahamas shoals source of mud
100Appalachians Ordovician Isolated Foreland Basin
101AppalachiansOrdovician
102Appalachians - Ordovician
103Appalachians - Ordovician
104Appalachians - Ordovician
105Appalachians - Ordovician
106Appalachians - Ordovician
107Appalachians Ordovician
108Appalachians - Ordovician
109Appalachians - Ordovician
deepening up from grains to mud
110Appalachians - Ordovician
111Appalachians Ordovician
112Murray Basin
113Murray Basin
114Lime muds organics sequestered in axial
trough tidal flats
Ooid Tidal Deltas
Skeletal Sands
Reefs Coralgal Sands
Pellets Grapestones
Coastal Sabkha
Cyanobacterial mats
Cyanobacterial mats
115Lime mud organics sequestered in
Mangrove swamp tidal flats
116Intertidal Sand Mud Flats
Tidal Channels
Hardgrounds
Beach Ridges
Cyanobacterial Mats
Sabkha
117Whitings
118Geologic Cross-Section - Arabian Gulf
119Lime Source
Gas
Paleozoic Stratigraphic Column Arabia
Gas
120Jurassic Formations of Arabia