ofp rr-iI wo iiaternary from , California U.S. GEOLOGICAL SUHVEY PROFESSIONAL PARER 1363 AVAILABILITY OF BOOKS AND MAPS OF THE U.S. GEOLOGICAL SURVEY Instructions on ordering publications of the U.S. Geological Survey, along with prices of the last offerings, are given in the cur­ rent-year issues of the monthly catalog "New Publications of the U.S. Geological Survey." Prices of available U.S. Geological Sur­ vey publications released prior to the current year are listed in the most recent annual "Price and Availability List" Publications that are listed in various U.S. Geological Survey catalogs (see back inside cover) but not listed in the most recent annual "Price and Availability List" are no longer available. 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E-146, 701 C St. Maps For maps, address mail orders to U.S. Geological Survey, Map Distribution Maps Federal Center, Box 25286 Maps may be purchased over the counter at the U.S. Geologi­ Denver, CO 80225 cal Survey offices where books are sold (all addresses in above list) and at the following Geological Survey offices: Residents of Alaska may order maps from ROLLA, Missouri-1400 Independence Rd. Alaska Distribution Section, U.S. Geological Survey, DENVER, Colorado-Map Distribution, Bldg. 810, Federal New Federal Building - Box 12 Center 101 Twelfth Ave., Fairbanks, AK 99701 FAIRBANKS, Alaska-New Federal Bldg., 101 Twelfth Ave. Palynology of Two Upper Quaternary Cores from Clear Lake, Lake County, California By DAVID P. ADAM With a section on DATING By STEPHEN W. ROBINSON U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1363 The climatic sequence derived from a continuous pollen record spanning the last full glacial cycle indicates several large and sudden shifts in climate during the early part of the last glacial cycle between 125,000 and 75,000 years ago. UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1988 DEPARTMENT OF THE INTERIOR DONALD PAUL HODEL, Secretary U.S. GEOLOGICAL SURVEY Dallas L. Peck, Director Library of Congress Catalog card No. 88-600599 For sale by the Books and Open-File Reports Section, U.S. Geological Survey, Federal Center, Box 25425, Denver, CO 80225 CONTENTS Abstract -------------------------- Results Continued Introduction- ------------------------ Zone descriptions Continued Acknowledgments -------------------- Core 4 Continued Description of the area ------------------- Zone H ------------------- 29 Geography and climate ----------------- Zone I ------------------- 29 Geology ------------------------- Zone J ------------------- 29 Geomorphology --------------------- Zone K ------------------- 29 Limnology- ----------------------- Zone L ------------------- 30 Zoogeography ---------------------- Zone M ------------------- 30 Phytogeography- -------------------- Zone N ------------------- 30 Distribution of major vegetation types ------- Zone 0 ------------------- 30 Oak woodland ------------------ Zone P ------------------- 30 Mixed hardwood forest ------------- Zone Q ------------------- 30 Chaparral -------------------- Zone R ------------------- 30 Coast Range montane forest ---------- Zone S ------------------- 30 Significant species distributions ----------- Zone T ------------------- 31 Oaks (Qwrmis spp.) --------------- 10 Zone U ------------------- 31 Pines ---------------------- 10 Core 7---------------------- 31 Other Pinaceae ----------------- 10 Zone A7------------------- 31 TCT species ------------------- 11 Zone B7------------------- 31 Background and previous work --------------- 11 Zone C7------------------- 32 Methods and procedures- ---------------- 12 Zone D7------------------- 32 Description of cores 4 and 7 ------------ 12 Pollen concentration ---------------- 32 Core sampling- ------------------- 13 Comparison of percentage and concentration curves 34 Pollen sample preparation- ------------- 13 The algal record ------------------ 39 Statistical methods ----------------- 16 Factor analysis ----------------- 39 Factor analysis ----------------- 16 Discussion- ------------------- 41 Zoning algorithm ---------------- 16 Dating, by Stephen W. Robinson ------------ 41 Results --------------------------- 17 Radiocarbon- -------------------- 41 Sediment density and carbon content ---------- 17 The old-carbon effect ---------------- 46 Palynology ----------------------- 17 Correlation with deep-sea record ---------- 48 Notes on variables ----------------- 17 Amino-acid racemization -------------- 49 Quercus (oaks) ------------------- 17 Interpretation of the fossil record ------------ 50 Pinus (pines) -------------------- 17 Pollen factors -------------------- 50 Abies (firs) --------------------- 18 Clustering of zones ----------------- 51 Picea (spruce) -------------------- 18 Paleoclimatic units ------------------- 51 Tsuga (hemlock) ------------------- 19 Reference section ------------------ 55 TCT (Taxodiaceae, Cupressaceae, and Taxaceae) - - 19 Definition of paleoclimatic units ----------- 55 Polygonaceae (buckwheat family) ---------- 19 Tsabal cryomer ----------------- 55 Gramineae (grasses) ----------------- 19 Konocti thermomer --------------- 55 Cheno-Ams --------------------- 19 Porno cryomer ----------------- 55 Other trees and shrubs --------------- 21 Boomli thermomers --------------- 55 Other aquatic and emergent plants --------- 21 Tsiwi cryomers ----------------- 55 Compositae (sunflower family) ----------- 21 Cigom cryomers ---------------- 55 Unknown A--------------------- 21 Halika thermomers --------------- 56 Other pollen types ----------------- 21 Tuleyome thermomer -------------- 56 Pediastrum --------------------- 21 Environmental history of Clear Lake basin ------- 56 Peridinium spp. cysts ---------------- 25 Tsabal cryomer ------------------- 56 Pollen zone definition ------------------ 26 Konocti thermomer ----------------- 57 Factor analysis results --------------- 26 Porno cryomer ------------------- 57 Zone boundaries ------------------ 27 Early Porno cryomer -------------- 57 Zone descriptions -------------------- 28 Onset of the Porno cryomer --------- 57 Core 4------------------------ 28 The Tsiwi cryomers and Boomli thermomers 59 Zone A --------------------- 28 Tsiwi 1 through Tsiwi 3--------- 59 Zone B --------------------- 28 Boomli 1 thermomer ---------- 59 Zone C --------------------- 28 Tsiwi 3 cryomer ------------- 60 Zone D --------------------- 28 Boomli 3 thermomer ---------- 60 Zone E --------------------- 28 Tsiwi 4 cryomer ------------- 60 Zone F --------------------- 29 Boomli 4 thermomer ---------- 61 Zone G --------------------- 29 Tsiwi 5 cryomer ------------- 61 III IV CONTENTS Environmental history of Clear Lake basin Continued Page Correlations Continued Page Porno cryomer Continued Other correlations Continued Early Porno cryomer Continued Northwestern Europe Continued The Tsiwi cryomers and Boomli thermomers Continued The Netherlands ---------------- 71 Boomli 5 thermomer ------------ 61 Sabana de Bogota, Colombia ------------ 72 Middle Porno cryomer ---------------- 61 Lake Biwa, Japan ------------------ 72 Cigom 1 cryomer ---------------- 61 North America ------------------- 73 Pollen zone FA and the Halika thermomers - - - 61 The Sangamonian Stage ------------ 73 Late Porno cryomer ----------------- 62 Long North American sequences -------- 73 Cigom 2 cryomer ---------------- 62 Illinois- ---------------------