University of North Dakota UND Scholarly Commons Theses and Dissertations Theses, Dissertations, and Senior Projects 1985 Late Quaternary environmental and climatic history of the southern Chilean Lake Region interpreted from coleopteran (beetle) assemblages John W. Hoganson University of North Dakota Follow this and additional works at: https://commons.und.edu/theses Part of the Geology Commons Recommended Citation Hoganson, John W., "Late Quaternary environmental and climatic history of the southern Chilean Lake Region interpreted from coleopteran (beetle) assemblages" (1985). Theses and Dissertations. 141. https://commons.und.edu/theses/141 This Dissertation is brought to you for free and open access by the Theses, Dissertations, and Senior Projects at UND Scholarly Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of UND Scholarly Commons. For more information, please contact [email protected]. LATE QUATERNARY ENVIRONMENTAL AND CLIMATIC HISTORY OF THE SOUTHERN CHILEAN LAKE REGION INTERPRETED FROM COLEOPTERAN (BEETLE) ASSEMBLAGES by John W. Hoganson r Bachelor of Arts I North Dakota State University, 1970 Master of Science ! University of Florida, 1972 I I A Dissertation Submitted.to the Graduate Faculty of the f University of North Dakota in partial fulfillment of the requirements for the degree of Doctor of Philosophy Grand Forks, North Dakota December 1985 .r ,· ·~;­ {. ·'/ ( l This dissertation submitted by John W, Hoganson in partial fulfillment of the requirements for the Degree of Doctor of Philosophy from the University of North Dakota is hereby approved by the Faculty Advisory Committee under whom the work has been done, This dissertation meets the standards for appearance and conforms to the style and format requirements of the Graduate School of the University of North Dakota, and is hereby approved. Dean of the Graduate School -ii- Permission Title Late Quaternary Environmental and Climatic History of the Southern Chilean Lake Region Interpreted from Coleopteran I (Beetle) Assemblages ~ 'I Department Department of Geology Degree Doctor of Philosophy In presenting this dissertation in partial fulfillment of the requirements for a graduate degree from the University of North Dakota, I agree that the Library of this University shall make it freely available for inspection. l further agree that permission for extensive copying for scholarly purposes may be granted by the professor who supervised my dissertation work or, in his absence, by the Chairman of the Department or the Dean of the Graduate School. It is understood that any copying or publicati.on or other use of this dissertation or part thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of North Dakota in any scholarly use which may be made of any material in my dissertation • . -iii- TABLE OF CONTENTS LIST OF PLATES. • • • • • • . • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • vi LIST OF FIGURES. • • • .. • • .. .. • .. • .. • .. • .. • • .. .. • • .. • • .. .. .. .. • .. .. .. .. • .. .. .. .. .. .. .. .. • .. • vii LIST OF TA.BLES.... • • • .. • • .. .. .. • • • .. .. .. .. • .. • .. • .. • .. • • .. • .. • .. .. .. • • • • .. • .. .. .. • • .. .. • • .. .. ix ACKNOWI..EDGMENTS ..... ., .. • • • • • • .. .. .. .. .. • • .. .. .. • .. .. .. • .. .. .. • .. • .. • • • • • • .. .. • .. .. • • .. .. .. • .. xii ,ABS TRACT • • .. • • .. .. .. .. .. • • • • .. • .. • • • • • • .. .. • .. • • .. • • .. .. .. .. .. .. .. • • .. • • .. • • • • • .. .. • • .. • .. .. • .. xv I INTRODUCTION.... • • • • .. .. • • • • • .. .. .. .. .. .. • • • • • • . .. .. .. .. .. .. .. .. .. .. .. • • . • .. 1 II PREVIOUS WORK......................................................................... 7 Quaternary Paleoclimatic Studies in Southern South America Beetles as Indicators of Quaternary Environments and Climates III STTJDY AREA........................................................................... 29 Physiography, Tectonic History and Pre-Quaternary Geology Quaternary Geology Present Climate Regional Vegetation IV METHODS. • . • • • • .. • .. • .. • .. .. • .. • • . .. • • • ... • • • .. • • .. .. .. • .. • .. • .. .. • • • . .. .. .. .. .. 45 Field Methods Laboratory Procedures Mathematical Treatment V PUERTO OCTAY SITE •..•.••• ,................................................... 58 Location, Site Description and Radiocarbon Chronology Analysis of the Fossil Assemblages Paleoenvironmental and Paleoclimatic Interpretations Discussion VI PUERTO VABAB PARK SITE ............................................... 102 Location, Site Description and Radiocarbon Chronology Analysis of the Fossil Assemblages Paleoenvironmental and Paleoclimatic Interpretations Discussion -iv- VII PUERTO VARAS RAILROAD SITE •.••• , • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 116 Location, Site Description and Radiocarbon Chronology Analysis of the Fossil Assemblages Paleoenvironmental and Paleoclimatic Interpretations Discussion VIII RIO CAUNAHUE SITE ............................................... 131 Location, Site Description and Radiocarbon Chronology Analysis of the Fossil Assemblages Paleoenvironmental and Paleoclimatic Interpretations Discussion IX DISCUSSION OF THE LATE QUATERNARY CLIMATIC HISTORY OF THE LAKE REGION. • . • • • • • • • • • • • • • • . • • . • • • • • • • . • • • • • • • . • . • • • • • • • • • 168 X CONCLUSIONS... • • • • • • . • • . • • • • • • • • . • . • . • • • • • • • • • • . • • • • • • • • • . • • • 193 XI ILLUSTRATIONS OF REPRESENTATIVE BEETLE FOSSILS •••••••••••••••• 197 XII APPENDICES ............................................................ 212 APPENDIX A. Coleoptera Bioassociations Along an Elevational Gradient in the Lake Region of Southern Chile and Comments on the Postglacial Development of the Fauna ....................................... 213 APPENDIX B. Sample Processing Procedures for Extraction of Insect Fossils ••.••....••••.••.•..•••.•..... 269 APPENDIX C. List of Coleopterists Consulted During this Study .......................................... 275 APPENDIX D. Radiocarbon Dates Obtained for this Study •••••• 281 XII I REFERENCES CITED • ......................... , .... ,. .. • . • .. .. .. • • • .. • . • • 285 I I -v- LIST OF PLATES Plate lA, Chart showing stratigraphic sections of the fossil sites, sample intervals, levels of radiocarbon dates, taxonomic list of Coleoptera and other insects and arachnids and fossil abundances (part) .................................... ;.......... in pocket lB. Chart showing stratigraphic sections of the fossil sites, sample intervals, levels of radiocarbon dates, taxonomic list of Coleoptera and other insects and arachnids and fossil abundances (continued) •••.••••••••••••••••••••••• in pocket 2, Scanning electron photomicrographs of Listroderes dentipennis, Pentarthrum castaneum, Wittmerius longirostris, and Dasydema hirtella. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 198 3. Scanning electron photomicrographs of Nothoderodontus dentatus, Strictospilus darwini, Caenocara sp,, and Perilopsis £lava. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 200 4. Scanning electron photomicrographs of Abropus carnifex, Hydrochus stolpi, cf. Diontolobus sp. 2, and Baryopsis araucanus. • . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 202 S. Scanning electron photomicrographs of Monarthrum sp., Agonum sp. 2, Hydora annectens, and Nominocerus marginicollis ••••••• 204 6. Scanning electron photomicrographs of Phloeotribus cf. spinipennis, Brachypterus n. sp., Glypholoma pustuliferum, Tartarisus signatipennis, Rhychitomacer flavus, Austrolimnius chiloensis, and Plectocephalon testaceum ••••••• 206 7. Scanning electron photomicrographs of Eunemadus chilensis, Rhopalomerus tenuirostris, Neophonus bruchi, Leucotachinus luteonitens, Epaetius carinulatus, and Anotylus chilensis •••• 208 8. Scanning electron photomicrographs of Trechinotus striatulus, Gipsyella patagonica, Neoelmis n. sp., Lophocephala fasciolata, Cryptorhynchinae gen. indet. 2nd Minurus testaceous •••••••••••.•.••••••••••.....•.•••••... 210 -vi- - ti-~ ~ .,. "'~14:,, ';t ,, ~-· ~ «:~ ~ ~ , A', • '/;~, " • LIST OF FIGURES Figure 1. Ma~ of the southern portion of the Chilean Lake Region showing drift sheets, moraine belts, volcanoes and location of f orsi' '1 sites· ...................... " .............................. 13 2. 1 ~t~::;; ~:ieg:~!~!!~.~~:.~~.~~:.:~~~~:~~.::~~~~~.~:.~~: ........ 30 3. (Ai Generalized cross-section along the 41st parallel from the Peru-Chile Trench to the Andes. (B) North-south cross­ se!tion through the southern portion of the Lake Region drawn fr m ENAP exploratory well data................................ 32 4. To ographic maps of the areas of fossil sites. (A) Rio ~:~~:~~:.:~~~: .• ~~~--~~:~:.~~~~:.~:~~: .. :~: •• ~~~~~-~~:~~-···· 59 5. Vi~w of the abandoned Puerto Octay spillway •••••••••••••••••••• 60 6. Ph~tograph of the piston corer and some of the cores recovered from the Puerto Octay Site •••••••••..•••••••••••••••• 60 ! 7. Phptograph of coring at the Puerto Octay Site •••••••••••••••••• 61 8. Ph~tograph of the Puerto Varas Park section exposed in Bella Virta Park taken from the north across route CH225 ••••••••••••• 104 9. Photograph of Allan Ashworth sampling the Puerto Varas Park pejat horizon ......... ,. ............................................. 104