SHELL REPORT: SAND FACIES AND THEIR ENVIRONMENTS IN NW GULF OF MEXICO

H. A. BERNARD, C. F. MAJOR, and B. S. PARROTT

Search and Discovery Article #60002 (1999)

GEOLOGICAL MISCELLANEOUS- 16; HOUSTON, TEXAS, SEPTEMBER 1958

PROPERTY OF SHELL DEVELOPMENT COMPANY. The information contained herein is considered confidential by Shell Development Company. Exportation of this document is subject to license under the Export Control Act of 1949.

Illustrations
Abstract
Introduction
Classification of Environments of the Northwestern Gulf of Mexico
   Continental Environments
   Transitional Environments
   Normal Marine Environments
Alluvial Environments
   Meander Belt
      Point Bar
         Sequence in Grain Size
         SP Character
         Sequence in Sedimentary Features
            Small Ripple Bedded Features
            Horizontally Bedded Features
            Giant Ripple Bedded Features
            Poorly Bedded Features
            Gradational Zonation in Sequence of Sedimentary Features
            Miscellaneous Sedimentary Features
         Organic Remains
         Directional Features
            Cross Bedding
            Grain Orientation
         Geometry, Size, and Prediction in Trend
      Abandoned Channels
   Flood Basin or Backswamp
Deltaic Environments
   Classification of Deltas
   Genesis of a Delta
   Deltaic Subenvironments and the Mississippi Delta
      Deltaic Plain
      Pro Deltaic Plain
Pro Deltaic Plain Fringe
Pro Deltaic Plain Distal
   Deltaic Foraminiferal Assemblages
   Generalized Deltaic Sediment Distribution
      Deltaic Plain
      Pro Deltaic Plain
   Sedimentary Features Common to Deltaic Deposits
      Deltaic Plain
         Distributary Channel Fill and Natural Levee
         Point Bar
         Flood Basin
      Pro Deltaic Plain 
         Fringe
         Distal
      Other Features in the Mississippi Deltaic Area
   Geometry and Sequence of Sedimentary Features
      Mississippi-St. Bernard Subdelta
      Pleistocene Mississippi-Neptune Delta
      Sequence of Fringe Deposits and SP Log Character
      Sequence of Channel Fill Deposits and SP Log Character
      Sequence of Deltaic Point Bar and Other Deposits
      Bar Finger "Sands" of Fisk
   Brazos and Rio Grande Deltas
      Pro Deltaic Plain
         Sequence and SP Log Character
      Deltaic Plain
            Meander Belt
            Flood Basin
            Wood and Fauna
            Sequences and SP Log Character
Interdeltaic-Marine and Marine Environments
   Galveston Barrier Island and Associated Environments
      Genesis
      Bottom Sediments
      Sedimentary Features
      Sequence
      SP Log Character
      Foraminiferal Assemblages
      Directional Features
      Geometry
   Transgressive Beach and Associated Regressive Mud Flat
   Environment
      Genesis, Geometry, and Nature
      Directional Features
   Marine Environments and Shelf Sands
Summary
Bibliography

LIST OF ILLUSTRATIONS

Figure

1. Occurrence of Recent depositional environments in the northwestern Gulf of Mexico.
2. Classification of depositional environments of the northwestern Gulf of Mexico.
3. Recent alluvial valley of the Brazos River near Richmond, Texas.
4. Brazos meander belt near Richmond, Texas.
5. Alluvial valley environments.
6. Cross section of Brazos point bar deposits near Richmond, Texas.
7. Cross sections of small-scale ripple bedded, point bar sands.
8. Horizontally bedded point bar sands.
9. Giant ripples and giant ripple bedded point bar sands.
10. Giant ripple bedded sands.
11. Poorly bedded, point bar gravel and coarse sand.
12. Sequence of bedding features found in point bar deposits.
13. Miscellaneous sedimentary features of point bar deposits.
14. Giant ripple foreset directions in Brazos point bar deposits.
15. Dip directions of foreset beds in zone of giant ripple bedded sands of a Brazos point bar.
16. Expected cross bedding directions of giant ripple bedded sands of Mississippi point bars.
17. Grain orientation in horizontally bedded sands of a point bar deposit.
18. Grain orientation in horizontally bedded and small ripple bedded deposits of a point bar deposit.
19. Comparison of Mississippi and Brazos point bar deposits.
20. Typical world deltas.
21. Typical world deltas.
22. Block diagrams illustrating the development of Mississippi subdeltas.
23. Mississippi deltaic environments.
24. Distribution of foraminiferal biofacies in the Mississippi Delta Area.
25. Bottom sediment distribution, vicinity of Mississippi Delta.
26. Distribution of Mississippi deltaic deposits characterized by sedimentary features.
27. Marsh and shallow fringe deposits of the Mississippi Delta.
28. Deep fringe and distal pro deltaic plain deposits.
29. Cross section of St. Bernard-Mississippi Delta.
30. Fence diagram of a Pleistocene Mississippi Delta.
31. Cross sections of LaFourche-Mississippi Delta.
32. Sedimentary framework, modern Mississippi Delta.
33. Brazos River Delta.
34. Representative section of modern deltaic deposits of the Brazos River.
35. Fence diagram of the Rio Grande Delta. .
36. Representative section of point bar deposits of the Rio Grande Delta.
37. Late Quaternary geology and facies of southeast Texas.
38. Galveston Island beach accretions.
39. Bottom sediments in vicinity of Galveston Island.
40. Sedimentary features of deposits in vicinity of barrier islands.
41. Cross sections of barrier island deposits.
42. Representative section of Galveston barrier island deposits.
43. SP character of principal sand facies of Recent depositional environments.
44. Foraminiferal assemblages in the vicinity of Galveston Island.
45. Grain orientation in Galveston barrier island deposits.
46. Block diagram of Galveston barrier island deposits.
47. Chenier plain of southwestern Louisiana showing beaches and mud flats.
48. Chenier plain cross sections of transgressive beach and regressive mud flat deposits.
49. Grain orientation in cheniers or abandoned beach ridges.
50. Bottom sediment distribution on continental shelf off Louisiana and southeast Texas.
51. Representative section of marine shelf sands off southwest Louisiana and southeast Texas.
52. Trends of Recent and late Pleistocene sand bodies of coastal Louisiana and Texas.

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