Whitings – Source of Black Gold?

1. 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

2. 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

3. Hypothesis • Significant Holocene accumulations of cyanobacteria & lime mudin 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!

4. 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

5. MIDDLE EAST FIELDS Location of Middle Eastern Oil Fields

6. 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

7. 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!

8. 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

9. 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.

10. 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.

11. Evidence • Significant Holocene accumulations of cyanobacteria & lime mudin 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!

12. Carbonate Provinces - Arabian Gulf Basin Ramp Open Shelf Restricted Shelf

13. 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

14. Weather Station Data Temperatures - pink & MPH windspeed - black. Windspeeds over 25mph coincide with regional "Whiting" blooms.

15. Arabian Gulf Factory producing carbonates & storing products of cyanobacteria since Permian NASA Image

16. A big day for a bloom!! Organics in the Gulf! Nasa Image

17. Whitings common to-day and common back in the Triassic! Organics in the Gulf! Nasa Image

18. 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.

19. 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 Local Whiting Occurrences!

20. PG Gulf Major Source Direct Precipitation

21. Persian Gulf Facies Distribution After Wilkinson & Drummond, 2004

22. Persian Gulf Mud Distribution After Wilkinson & Drummond, 2004

23. 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

24. 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

25. Lime mud & organics sequestered in Mangrove swamp tidal flats

26. Shoaling Upward Inner Shelf Cycle Shoaling Up Cycle

27. Abu Dhabi – Mud Flats

28. Abu Dhabi – Mud Flats

30. High Intertidal Cyanobacterial Flats Intertidal Carbonate Flats Earlier High Energy Beaches Supratidal Sabkha Evaporites

32. Tidal Ponds Tidal Creek

33. Tidal Pond Tidal Creek & Cyanobacterial Megapoygons

34. Cyanobacterial Peat

36. Crinkled Algal Mat Gypsum Mush Cyanobacterial Peat

38. SURFACE ANHYDRITE POLYGONS

39. Anhydrite Cyanobacterial Peat Intertidal Muds

41. HALITE POLYGONS

42. Washover Sediments Anhydrite Cyanobacterial Peat

44. MICROTOME OF CYANOBACTERIAL MATS

47. Modern Sources of lime mud • Isolated seas – Arabian Gulf • Wide platforms in nutrient deserts of tropical seas – Bahamas

48. 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

49. Bahamas Ocean Drilling Transect Kramer, Swart, DeCarlo & Schosvbo, 2005

50. Modern Sources of lime mud • Isolated seas – Arabian Gulf • Wide platforms in nutrient deserts of tropical seas – Bahamas