Stratigraphy and Structure of the Goajira Peninsula, Northwestern Venezuela and Northeastern Colombia

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Papers from the University Studies series (The University of Nebraska) University Studies of the University of Nebraska 1965 Stratigraphy and Structure of the Goajira Peninsula, Northwestern Venezuela and Northeastern Colombia John F. Rollins University of Nebraska - Lincoln Follow this and additional works at: https://digitalcommons.unl.edu/univstudiespapers Part of the Geology Commons, Stratigraphy Commons, and the Tectonics and Structure Commons Rollins, John F., "Stratigraphy and Structure of the Goajira Peninsula, Northwestern Venezuela and Northeastern Colombia" (1965). Papers from the University Studies series (The University of Nebraska). 76. https://digitalcommons.unl.edu/univstudiespapers/76 This Article is brought to you for free and open access by the University Studies of the University of Nebraska at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Papers from the University Studies series (The University of Nebraska) by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. John F. Rollins , " new senes no. 30 University of Nebraska Studies march 1965 Stratigraphy and Structure of the Goajira Peninsula, Northwestern Venezuela and Northeastern Colombia John F. Rollins Stratigraphy and Structure of the Goajira Peninsula, Northwestern Venezuela and Northeastern Colombia university of nebraska studies : new series no. 30 published by the university at lincoln : march 1965 The University of Nebraska The Board of Regents RICHARD E. ADKINS VAL PETERSON, president J. G. ELLIOTT JOSEPH SOSHNIK, corporation secretary B. N. GREENBERG, M.D. CLARENCE E. SWANSON J. LEROY WELSH The Chancellor CLIFFORD M. HARDIN Acknowledgments Sincere appreciation is extended to Professor W. M. Gilliland, Chairman of the Department of Geology at the University of Ne braska, for his support and encouragement in the preparation of this study and for helpful suggestions made during a visit to the region in question. Thanks are due also to several University of Nebraska faculty members-Professors A. L. Lugn and C. B. Schultz for critical reading of the manuscript and Professors T. M. Stout and J. A. Fagerstrom for reviewing some of the stratigraphic con cepts and the biostratigraphy. Part of the work was done as a field project for the Richmond Exploration Company. The rest of the study was completed, with certain financial aid from the company, while the writer was on educational leave of absence from the company. Several Richmond geologists, including P. B. McGrath, L. R. Cook, and J. B. Miller, furnished initial information on the area and also offered encour agement and suggestions. Mr. Miller reviewed the final manuscript. R. S. Jaroska and A. B. Whitman did the microfaunal determina tions and prepared the zonation charts. Thanks are also due the Creole Petroleum Corporation for permitting G. H. Fraunfelter to study some of the macrofaunal collections. Hans BurgI of the Instituto Geologico Nacional de Colombia also studied much of the macrofaunal collection. Finally, the writer is deeply grateful to his wife, Constance Rollins, for her continuous help in the field and in the preparation of the manuscript. Contents Stratigraphy.......... ..... ............................. ..... ... .... ...... ....... ... ................... 1 Resume of the Biostratigraphy ...... ...................................................... 60 Structural Geology ................................................................................ 64 Summary of Geologic History ............................................................ 88 Selected Bibliography ............ ......... ..... .... ..... ......... ..... ... ......... ......... .... 96 Appendix 1: Revision of Stratigraphic Nomenclature .................. 100 Appendix 2: Detailed Stratigraphic Sections .................................... 102 Illustrations Map Geologic Map of the Goajira Peninsula, Northwestern Venezuela and Northeastern Colombia................. (In pocket inside back cover) Text Figures 1. Index Map of Maracaibo Basin.... ............. ............................... xii 2. Physiographic Sketch Map, Goajira Peninsula. ............... ..... xvi 3. Stratigraphic Chart, Goajira Peninsula.................................... 2 4. Stratigraphic Diagram, Palanz Formation .................................. 20 5. Jurassic and Cretaceous Reef Development ............................ 22 6. Faunal Zones, Yuruma Group .................................................... 31 7. Regional Correlation of Cretaceous, Northwestern Venezuela 42 8. Stratigraphic Correlation of the Siamana, Uitpa, and Jimol Formations With Venezuela, Trinidad, and the U.S. Gulf Coast ................................................................................................ 51 9. Goajira Peninsula Correlation Section ....................................... 54 10. Chart of Principal Biostratigraphic Zones, Goajira Peninsula ....................................................................................... 61 11. Regional Tectonic Framework, Western Venezuela ................ 65 12. Mesozoic Tectonic Framework of the Goajira ....................... 66 13. Tectonic Sketch Map of the Goajira Peninsula ........................ 68 14. Illustration of Strike-Slip Fault Pattern Due to Compression 71 15. Peri-Anticlinal Fault Patterns ...................................................... 73 16. Relation of Axis of Maximum Compression to Average Trends of Fault Sets in Part of Cocinas Trough..................... 82 17. Genesis of Cocinas Structural Patterns ........................................ 83 18. Paleogeographic and Lithofacies Sketch Maps Showing Sedi mentary Development of the Goajira Qurassic-Cretaceous) .... 92 19. Paleogeographic and Lithofacies Sketch Maps Showing Sedi mentary Development of the Goajira (Cretaceous-Tertiary) ... 93 20. Evolution of Stratigraphic Terminology for Goajira Peninsula ........................................................................................ 101 Introduction The Goajira Peninsula forms the northernmost extension of continental South America (see Fig. 1). Its lobate outer portion, the area of this geologic study, is a mountainous region about 75 kilometers wide at its widest part and juts 150 kilometers north eastward into the Caribbean Sea. Although only about 110 kilometers north of the city of Maracaibo, Venezuela, the Peninsula is isolated and little known. Only a narrow coastal strip lies in Venezuela; the remainder is in Colombia; but the Peninsula is largely a desert wasteland not exten sively entered by people other than its own sparse Indian popula tion. Its remoteness has long led it to be called the "Forgotten Land of Colombia." The exposures of Mesozoic and Cenozoic rocks on the Penin sula present a seldom equalled opportunity for fundamental study in stratigraphy, structure, and sedimentation. Probably few places in all of northern South America present a comparable area for the study of Cretaceous limestone lithology and deposition. Because of the arid nature of the region, the rocks are well exposed in most areas. As a result the outcrops can be studied in detail and lateral changes can be observed instead of surmised. The sedimentary, metamorphic, and igneous rocks found in the Goajira indicate a long and varied geologic record. The sedimentary section is made up of a thick sequence of Mesozoic and Cenozoic strata. Of particular interest from a regional viewpoint is the succession of Cretaceous limestones, shales, and sandstones. In addition, structural deformation of a complex nature clearly demonstrates some of the basic phenomena of the compressive deformation of rocks. On the southeastern part of the Peninsula compressive stresses have buckled the sediments of the Cocinas trough into an asymmetrically overturned and severely faulted anti clinal structure. Farther northward, the Serranias Jarara and Macuire have been uplifted into their present position after a much earlier period of severe crumpling. Metamorphism and igneous activity of several periods have further complicated the geology. xi ~RU8A CUR"Z~ IION"'~ RELIEF MAP MARACAIBO BASIN (AFTER SUTTON) SCALE o 20 40 &0 10 toO r---t;;;;;;t t&;;;;;j I KILOMETERS ~ Oil FIELDS FIG. -I INDEX MAP Introduction / xiii The five primary objectives of this research project were: (1) to study in detail the stratigraphic succession of both the Mesozoic and Cenozoic rocks, with special attention to the Cretaceous lime stone sequence; (2) to correlate the formations of the Goajira with the stratigraphic succession elsewhere in western Venezuela; (3) to propose an areal synthesis of the orderly sequence of geologic events which occurred on the Goajira as interpreted from the field data; and (4) to reconcile and integrate observations made on aerial photographs with those made in the field. Previous Work Until comparatively recently, the Goajira Peninsula has remained as one of the last frontiers in Venezuelan and Colom bian geology. The extent of the ignorance about the geology in this region before 1947 is summarized in the opening statement of Bucher's discussion of the Goajira: Not enough reliable information is available concerning the geology of the Goajira Peninsula to warrant an attempt at map presentation. (Bucher, 1952, p. 64.) His comments are based upon Stutzer (1928), the only pub lished study of the region prior to 1952. Primarily, the reason

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