Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1974 Morphodynamics and Sedimentation of the Rio Guayas Delta, Ecuador. Rodolfo Cruz-orozco Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Cruz-orozco, Rodolfo, "Morphodynamics and Sedimentation of the Rio Guayas Delta, Ecuador." (1974). LSU Historical Dissertations and Theses. 2716. https://digitalcommons.lsu.edu/gradschool_disstheses/2716 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. INFORMATION TO USERS This material was produced from a microfilm copy of the original document. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the original submitted. The following explanation of techniques is provided to help you understand markings or patterns which may appear on this reproduction. 1. The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting thru an image and duplicating adjacent pages to insure you complete continuity. 2. When an image on the film is obliterated with a large round black mark, it is an indication that the photographer suspected that the copy may have moved during exposure and thus cause a blurred image. You will find a good image of the page in the adjacent frame. 3. When a map, drawing or chart, etc., was part of the material being photographed the photographer followed a definite method in "sectioning" the material. It is customary to begin photoing at the upper left hand corner of a large sheet and to continue photoing from left to right in equal sections with a small overlap. If necessary, sectioning is continued again — beginning below the first row and continuing on until complete. 4. The majority of users indicate that the textual content is of greatest value, however, a somewhat higher quality reproduction could be made from "photographs" if essential to the understanding of the dissertation. Silver prints of "photographs" may be ordered at additional charge by writing the Order Department, giving the catalog number, title, author and specific pages you wish reproduced. 5. PLEASE NOTE: Some pages may have indistinct print. Filmed as received. Xerox University Microfilms Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. 75 - 1 4 ,2 3 9 CRUZ-OROZCO, Rodolfo. 1936- MORPHODYNAMICS AND SEDIMENTATION OF THE RIO GUAYAS DELTA, ECUADOR. The Louisiana State University and Agricultural and Mechanical College, Ph.D., 1974 Geology Xerox University Microfilms, Ann Arbor, Michigan48 ioe THIS DISSERTATION HAS BEEN MICROFILMED EXACTLY AS RECEIVED. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ftiûRPHODYNAMICS AND SEDIMENTATION OF THE RIO GUAYAS DELTA, ECUADOR A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy The Department of Marine Sciences by Rodolfo Cruz-Orozco B.S., Instituto Politecnico Nacional, 1962 M.S., Louisiana State University, 1971 December, 1974 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGMENT The writer expresses his sincere and deep gratitude to Dr. Wm.G. Mointire, former director of Coastal Studies Institute and currently Associate Director of the Center for Wetland Resources,for his encouragement during this study and for his assistance in preparing and reviewing the manuscript! to Dr. H.H. Roberts for his assistance during the writing and presentation of the manuscript; to Dr. Wte.G. Smith for his assistance during the field and laboratory work; to Dr. J.M. Coleman, Acting Director of Coastal Studies Institute, for his support and suggestions in preparation of the manuscript; to Dr. H.V. Andersen for his assistance in identifying the foraminifera; and to Dr. S.N. Gagliano for his assistance. Thanks are extended to Captain Hernandez (of the Huavaipe) for assistance during field work; and to Mr. Eduardo Zambrano and Mr. Guillermo Banos for their assis­ tance in field and laboratory work in Guayaquil. Thanks are due to Mrs. Gerry Dunn and Miss Valeri Dunn for preparation of the drawings, and to Mrs. Shirley Gerald for her editorial work. The author is indebted to the Consejo Nacional de ii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Cienola y Tecnologia de Mexico for its economic support, and special appreciation is extended to Dr. Agustin Ayala- Castanares. Special thanks are due to the Instituto Nacional de Pesca and the Servicio Hidrografico y Oceanografioo de la Armada del Ecuador for outstanding logistical support during this research. Financial support for this study was provided by the Geography Programs of the Office of Naval Research under Contract NOOOl4-69-A-0211 -000], Project NR ]88 002, with Coasted Studies Institute, Louisiana State University. iii Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS Page INTRODUCTION ........ 1 PHYSICAL SETTING ................................... 6 Delta and Adjacent Coastal Morphology*•••••••••• 14 Delta Pl a i n ........................ 15 Subaqueous Delta .... I7 Marginal Southeastern Deltas ......... 19 La Puntilla-Punta del Morro-Isla Puna Coasts.. 20 ENVIRONMENTAL INFORMATION .......................... 2? Data Collection and Techniques of Analysis...... 27 Hydrographie Setting................... 31 Suspended Sediments ...... 37 Bottom Sediments ..... 49 Texture .............................. 49 Composition ...... 53 I. Coarse Fraction ....... 5° A. Integral Component of Sediments $6 B. Specific Component of Sediments 56 a) Foraminifera ............. 56 b) Heavy Minerals.................. 59 II. Fine Fraction ........ 65 Sedimentary Structures of Marginal South­ eastern Deltas.......... 67 INTERPRETATION ................................. 71 COMPARISON OF RIO GUAYAS DELTA WITH THE ORD RIVER AND AMAZON RIVER DELTAS ........................ 82 CONCLUSIONS........................................ 89 BIBLIOGRAPHY...... 92 Appendix A. Granulometric Pfiurameters Computed by the Moment Measure Method .................. 94 B. Percentage of Occurrence of Heavy Minerals (200 grain point count) ....... 97 C. Percentage of Occurrence of Light Minerals and Other Light Particles (300 grain point count)...................... 99 D. Megascopic description of cores A-6, B-4, and C-2........................... 102 VITAE ............................................... 103 iv Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LIST OF TABLES Table Page 1 Average of the mean grain size and sorting degree of ten random stations located on the Rio Guayas* Estero de Chupaderos» Canal de Jambeli» and offshore west of Isla de Puna............. 5^ 2 Genera of foraminifera identified......... 57 3 Total percentages of heavy mineral suites and mafic rock fragments for the stations indicated... ....... 61 4 Comparison of morphological and oceanogra­ phical characteristics of high-tide deltas...... 83 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. LIST OP FIGURES Figure Page 1 Index map.......................... ....... 2 2 Morphology, bathymetry, two nodal points (A and B) and a linear shoal (C)...... 7 3 Annual rainfall and temperature for stations and years indicated............ 11 4a A small bank of dead Crassostrea corte- zienais found in the upper portion of the Salado estuary. The shells stand in a vertical position.(Photograph taken by Dr. Wm. G. Smith)....................... 18 4b Close-UD of a bank of Crassostrea which are very closely bounded and where some red mangrove has grown through .(Photo­ graph taken by Dr. Wm. G. Smith)........ 18 5 Morphological features at the Rio Jubones Alto Bajo delta........................ 21 6 Morphological features at the Isla de Jambeli.................... ............ 22 7a (a) Quaternary marine terrace dissected by an azxoyo on its eastern side; (b) small estuary (Rio Grande) displaying a braided channel; (c) barrier island vegetated, almost closing the mouth; (d) Punta Car- nero, a headland several meters high..... 23 7b Coast 10 km east of Chanduy. (a) Marine terrace dissected by a dendritic drainage pattern; (b) fault parallel to the shoreline; (c) cliffy terrace next to a narrow beach; (d) river mouth blocked by 23 8 Morphological features on southern shores of Isla de Puna............... ........ 26 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Figure Page 9 Positions of the sampling stations...... 28 10 Tidal current velocity field at (A) lunar hour zeroI (B) at lunar hour two (From Murray et al.» 1973) ............. 33 11 Tidal current