Depositional Systems and Hydrocarbon Resource Potential of the Pennsylvanian System, Palo Duro and Dalhart Basins, Texas

GC8008. Depositional Systems and Hydrocarbon Resource Potential of the Pennsylvanian System, Palo Duro and Dalhart Basins, Texas Panhandle, by S. P. Dutton. 49 p., 42 figs., 3 tables, 1980. ISSN: 0082-3309. Print.


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ABSTRACT
Pennsylvanian clastic and carbonate strata were deposited in a variety of environments within the Palo Duro Basin. Maximum accumulation (totaling 750 m or 2,400 ft) occurred along a northwest-southeast axis. Major facies include fan-delta sandstone and conglomerate, shelf and shelf-margin carbonate, deltaic sandstone and shale, and basinal shale and fine-grained sandstone.

Erosion of Precambrian basement in the adjacent Amarillo and Sierra Grande Uplifts supplied arkosic sand (granite wash) to fan deltas along the northern margin of the basin. Distal fan-delta sandstones grade laterally and basinward into shallow-shelf limestone. Deep basinal shales were deposited only in a small area immediately north of the Matador Arch.

Increased subsidence deepened and enlarged the basin throughout late Pennsylvanian time. Ultimately, the basin axis trended east-west with a narrow northwest extension. A carbonate shelf-margin complex having 60 to 120 m (200 to 400 ft) of depositional relief developed around the basin margin. The eastern shelf margin remained stationary, but the western shelf margin retreated landward throughout late Pennsylvanian time. Porous, dolomitized limestone occurs in a belt 16 to 32 km (10 to 20 mi) wide along the shelf margin. High-constructive elongate deltas prograded into the Palo Duro Basin from the east during late Pennsylvanian time. Prodelta mud and thin turbidite sands entered the basin through breaks in the eastern carbonate shelf margin.

Potential hydrocarbon reservoirs are shelf-margin dolomite, fan-delta sandstone, and high-constructive delta sandstone. Basinal shales are fair to good hydrocarbon source rocks on the basis of total organic carbon content. Kerogen color and vitrinite reflectance data indicate that source beds may have reached the early stages of hydrocarbon maturation.

Keywords: depositional systems, hydrocarbons, oil and gas, resource potential, Pennsylvanian, Palo Duro Basin, Dalhart Basin, Texas Panhandle, Texas

CONTENTS

Abstract

Introduction

Objectives

Methods

Regional setting

Pre-Pennsylvanian history.

Tectonic activity

Pennsylvanian System

Lower Pennsylvanian strata

Fan-delta systems

Modern fan-delta model

Distribution of granite-wash lobes

Lower Pennsylvanian fan-delta facies

Marine shelf and basinal systems

Upper Pennsylvanian strata

Shelf-margin systems

Shelf-margin retreat

Deltaic and basinal systems

Pennsylvanian-Permian transition

Diagenesis and porosity distribution

Petroleum potential

Source rocks

Thermal maturity

Reservoirs and traps

Conclusions

Acknowledgments

References

Figures

1. Structural elements of the Texas Panhandle and location of study area

2. Index map of study area showing well control and locations of cross sections in this report

3. Stratigraphic chart and general lithology of the Palo Duro Basin

4. Isopach map of Cambrian (?) sandstone, which directly overlies Precambrian basement

5. Isopach map of Lower Ordovician Ellenburger Group

6. Isopach map of Mississippian System

7. Structure contour map drawn on the top of Precambrian basement

8. Isopach map of Pennsylvanian System

9. Structure contour map drawn on the top of the Pennsylvanian System

10. Classification of granite-wash sandstone samples, Cottle County, using Folk's (1974) classification

11. Isopach map of a granite-wash lobe and core locations in Cottle County

12. Location map of Liguanea gravel fan delta, Kingston, Jamaica, showing drowned spit and associated reefs

13. Typical electric log patterns of fan-delta facies, shallow marine shelf and shelf-margin facies, and deltaic facies

14. Net granite-wash map of lower Pennsylvanian System

15. East-west Pennsylvanian cross section A-A', from Bailey to Cottle Counties

16. East-west Pennsylvanian cross section B-B', from Parmer to Childress Counties

17. North south Pennsylvanian cross section F-F', from Donley to Floyd Counties

18. Upward-fining sequence in granite wash from Standard and Robinson #2 Tippen well, Cottle County

19. Crossbedding in granite wash, Standard Oil #1 Barron well, Cottle County

20. Brachiopod wackestone from Standard Oil #1 Barron well, Cottle County

21. Net limestone map of lower part of the Pennsylvanian System

22. Schematic block diagram depicting the Palo Duro and Dalhart Basins in early Pennsylvanian time

23. Net granite-wash map of upper part of the Pennsylvanian System

24. Net carbonate map of upper part of the Pennsylvanian System

25. East-west Pennsylvanian cross section C-C', from Deaf Smith to Donley Counties

26. East-west Pennsylvanian cross section D-D', from Deaf Smith to Armstrong Counties

27. Schematic block diagram depicting Palo Duro and Dalhart Basins in late Pennsylvanian time

28. Net sandstone map of the upper Pennsylvanian System, including both granite wash and nonarkosic sandstone

29. East-west Pennsylvanian cross section E-E' through the Dalhart Basin from Dallam to Sherman Counties

30. Cross section G-G' in Cottle County through elongate-delta, bar finger sandstone

31. Block diagram of depositional environments in the modern Mahakam Delta and adjacent shelf, Indonesia

32. Matrix-supported, debris-flow conglomerate deposited in an upper submarine fan or feeder channel

33. Percent carbonate map of Wolfcampian strata showing position of Lower Wolfcampian shelf margins

34. Isopach map of upper Pennsylvanian dolomite based on sample log information

35. Isopach map of porous upper Pennsylvanian carbonate euhedral quartz overgrowths (Q) in Standard and Robinson #2 Tippen well, Cottle County

36. Ferroan-dolomite (ankerite?) cement (F) with undulose extinction in Standard and Robinson #2 Tippen well, Cottle County

37. Secondary porosity (P) in Standard and Robinson #2 Tippen well, Cottle County

38. Hydrocarbon shows from drill-stem tests and cuttings in Pennsylvanian carbonate, granite wash, and sandstone

39. Geothermal gradient map of Palo Duro and Dalhart Basins
40. Plot of total organic carbon (ToC) against depth for six wells having highest TOC values of Pennsylvanian samples

41. Distribution of total organic carbon in Pennsylvanian rocks of the Palo Duro Basin
42. Relation of kerogen color (thermal alteration index) and vitrinite reflectance values in Pennsylvanian source rocks to hydrocarbon facies

Tables

1. Wells used on cross sections in this report

2. Wells sampled for geochemical source-rock analyses

3. Reservoir potential of Pennsylvanian facies



Citation:
Dutton, S. P., 1980, Depositional Systems and Hydrocarbon Resource Potential of the Pennsylvanian System, Palo Duro and Dalhart Basins, Texas Panhandle: The University of Texas at Austin, Bureau of Economic Geology, Geological Circular 80-8, 49 p.