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Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG Annual Meeting 2012, AAPG Black Shale Core Workshop 2013, and AAPG Memoir 102)

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Page 1: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Regional Stratigraphy and Sedimentology of the Eagle Ford

Formation

Roger J. Barnaby

(My work was presented at AAPG Annual Meeting 2012, AAPG Black Shale Core Workshop 2013, and AAPG Memoir 102)

Page 2: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Late Cenomanian Paleogeography

Page 3: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Regional Cretaceous Stratigraphy: GOM

Page 4: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Eagle Ford Regional Sequence Stratigraphy

Page 5: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Eagle Ford Lithologies

• Limestones > 65% CaCO3 • Dunham texture, major grains

• Marls < 35% clay, 35-65% CaCO3 • Subdivided based on skeletal abundance

• Calcareous Shales > 35% clay

Limestone

Marl

Shale

Co

Py Si

Ca

Co

Py

Fm

Py

Ca

Co

Page 6: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Grain Types and Fossils

Foraminifera

Mollusks Pelecypods Inoceramids

Coccoliths Ammonite

Siliciclastic silt Phosphate grain

1 cm

Marl rip-up clasts

Pe

Fecal Pellets

Fish vertebrae Reworked volcanics

Page 7: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Eagle Ford Depositional Model

High TOC

Page 8: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Inner Shelf to Lower Shoreface

• Limestone-rich

• Grain-rich, intraclast-skeletal PS/GS

• Ripple lamination, mud drapes, erosion surfaces, skeletal lags, rip-up clasts, diverse fauna

• Intense bioturbation

Page 9: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Inner Shelf to Lower Shoreface

1.0 mm

Fm

Ph

1.0 mm

Fm

Mo

Ph

OM

Grain-supported/ grain-rich texture

Core close-up views Petrographic microscope images

Ripple laminations

Mud drapes

1 cm

Erosion surfaces

Rip-up clasts

1 cm

Bioturbation

1 cm

Soft-sediment deformation

1 cm

Page 10: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Mid-Shelf Tempestites

• Cyclically interbedded marl and skeletal limestone

• Limestones exhibit ripple lamination, scours and gutter casts, skeletal lags, rip-ups

• Flat laminated marls represent pelagic suspension below SWB

• Skeletal packstones record storm reworking and winnowing

Page 11: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Mid-Shelf Tempestites

0.5 mm

Ph

Ph

In

Fm

In

Rip-up clast

1.0 mm

Fm

In

OM

Pe

Rip-up clasts

1 cm

Scour surfaces

1 cm

Ripple laminations

Skeletal lag 1 cm

Gutter cast

Core close-up views Petrographic microscope images

Page 12: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Outer Shelf Distal Tempestites

• Laminated marl, thin laminae of foram PS

• Flat- to lenticular-laminated skeletal PS display small-scale scours, starved ripples, and graded bedding

• Pelagic suspension, distal storms

Flat lamination

Inoceramids

1 cm

Starved ripples

Graded bed

Scour

1 cm

Page 13: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Slope/Basin Hemipelagics

• Laminated-massive marl with thin foram laminae

• Flat lamination to graded beds

• Small horizontal burrows

• Suspension and turbidity currents below SWB

Faint lamination 1 cm 1.0 mm

F

m

O

M

Bu

Ph

Page 14: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Persian Gulf: Eagle Ford Modern Analog

Craton

Orogenic Highlands

Orogenic Highlands

Craton

Persian Gulf, depth < 250 ft

Shamal winds transport clay and silt to basin center

Epeiric sea on convergent margin between stable craton and orogenic highlands

500 mi

Page 15: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Persian Gulf Analog

Photic Zone 60-90 ft Bioturbation < 120 ft Storm Wave Base 75-150 ft

Shallow asymmetrical basin, sediment distribution function of water depth and shamal-generated waves Purser (1973)

Page 16: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Persian Gulf Analog

Highest TOC in unbioturbated planktonic marl below SWB Purser (1973)

Page 17: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Eagle Ford Parasequences

PS

PS

PS

PS

PS

PS

PS

10 0 ft

Page 18: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Progradational Facies Succession

Inner Shelf To Lower Shoreface

Mid- to Inner Shelf

Outer Shelf

20 10 0 FT

Page 19: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Vertical Stacking: Sequence Stratigraphy

GR 0 200

COREGR_api0 200

DEPTHFT

12750

12800

12850

12900

12950

BUDA

PS

PS

PS

PS

PS

PS PS

PS

PS

PS

PS

PS

PS

PS

PS

PS

PS

PS PS PS PS

PS

PS PS

PS

PS

PS

PS

PS

PS

Buda

K63 SB

K 65 MFS

K 69 SB

K 64 SB

K 72 SB

Page 20: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Outcrop Stratigraphy vs. Subsurface

Modified from: Donovan & Staerker (2010, 2011)

Page 21: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Regional Thickness, TOC, and CO3

100 mi

Page 22: Regional Stratigraphy and Sedimentology of the Eagle Ford ... · Regional Stratigraphy and Sedimentology of the Eagle Ford Formation Roger J. Barnaby (My work was presented at AAPG

Conclusions

• Eagle Ford: shallow-water (< 100 m) tempestite setting

• Water depth and SWB exert primary control on lithofacies

• Distal facies = highest TOC, proximal facies = lowest TOC

• Cyclic marls and limestones = layered heterogeneous reservoir

• Facies linked to mineralogy, can be interpreted from logs

• Vertical stacking patterns define 3rd order sequence stratigraphy for regional correlation and mapping