2003 Lost Lakes
Total Page:16
File Type:pdf, Size:1020Kb
Land of Lost Lakes the 2003 Desert Symposium Field Trip Robert E. Reynolds, Editor LSA Associates, Inc. with Abstracts from the 2003 Desert Symposium California State University, Desert Studies Consortium Department of Biological Science California State University, Fullerton Fullerton, California 92384 in association with LSA Associates, Inc. 1650 Spruce Street, Suite 500 Riverside, California 92507 April 2003 Desert Symposium 2003 Table of Contents Land of Lost Lakes: field trip guide Robert E. Reynold, David Miller, and Kim Bishop ......................................................................................................... 3 Ground water and ground-water discharge carbonate deposits in warm deserts R.M. Forester, D.M. Miller, and V.A. Pedone ............................................................................................................... 27 The evolution of Fort Irwin Neil C. Morrison ........................................................................................................................................................... 37 Miocene landslides within Avawatz Basin support hypothesis of a Paleozoic allochthon above Mesozoic metavolcanic rocks in theSoda and Avawatz Mountains, southeastern California Kim M. Bishop .............................................................................................................................................................. 42 Crucifixion thorn Maria A. Lum ................................................................................................................................................................ 48 Geology, genesis, and mining of pharmaceutical and food grade caldium carbonate at the Amboy Limestone Quarry Howard Brown .............................................................................................................................................................. 49 A 20-kyr climatic and hydrological history of Salton Basin, California, recorded by geochemical proxies in lacustrine deposits Hong-Chun Li ............................................................................................................................................................... 57 Abstracts from the 2003 Desert Symposium ....................................................................................................................................................................................... 61 Front Cover. View southeast across Soda Lake playa toward the Cow Hole and Old Dad Mountains. Back Cover. View northeast across Soda Lake playa toward the LIttle Cowhole Mountains and the Lava Beds district. Streams from springs incise the efflorescent saline crust that covers the playa. Brush and grasses are salt tolerant; mesquite trees have deep roots to reach fresh water. Reynolds, Robert E. (editor). Land of Lost Lakes. © 2003 California State University Fullerton, Desert Studies Consortium 2 Land of Lost Lakes Land of Lost Lakes: The 2003 Desert Symposium Field Trip Robert E. Reynolds, LSA Associates, Riverside, CA David Miller, U.S. Geological Survey, Menlo Park CA Kim Bishop, Department of Geological Sciences, California State University, Los Angeles, CA Introduction With the expansion of urban areas in southern California and southern Nevada and the increased utilization of areas between for recreation, major hydrological studies have focused on the southwestern states, where Pleistocene drainage systems and the subsurface aquifer flow between basins are being examined. The literature over the past 30 years discuss- ing Pleistocene basins refers to “green sediments” as the result of lacustrine deposition and as associated with intermit- tent playa deposits. Recent studies also recognize the presence of other water- and moisture-related deposition along fault scarps, at spring mounds, where bedrock causes aquifers to rise along water courses, in marshlands, and most important- ly, in areas separate from those systems where evaporative discharge occurs. Recent studies in the Mojave and Colorado deserts and the Basin and Range Province, also with scarce rainfall, have rec- ognized that these are lands that may not have been filled with Pleistocene lakes. Instead, deposition provides evidence of seasonal, fluctuating, structurally controlled drainage systems that were not a direct result of pluvial rainfall creating lacustrine deposits in every internally drained southwestern basin. This guidebook will examine different characteristics that represent lacustrine deposition, deposition around marsh lands and springs and deposition that is a result of evaporative groundwater discharge (E-GWD). The desert we will explore was thought of as a “Land that Lost Lakes,” but since this guide reviews the presence of many deposits that occur as a direct result of hydrological discharge, this volume is called “ The Land of Lost Lakes.” DAY 1 The route of Day 1 will introduce us to sedimentary fea- 15.6 (3.7) Exit the freeway. tures that are clearly lacustrine, deposited by Lake Manix. 15.8 (0.2) Stop, TURN LEFT (south). Our route will travel through Afton Canyon, a gorge that could only have been cut by a release of a large volume of 16.1 (0.3) PARK on the open area at the Basin Road of- water that eroded sedimentary dams. We will pass playas framp. that suggest ephemeral lacustrine deposition. The day will Stop 1.1. Ventifact Hill. Lake Manix breached 18.1 ka, end at West Cronese Lake, where we will see the contrast approximately the glacial maximum (17.8 ka) (Meek, between a groundwater discharge platform and the playa 1999). The sudden availability of sand from the Mojave surface of West Cronese Lake. We will see lacustrine fea- River delta caused granitic ventifacts to be carved by the tures of Lake Manix (green, lamellar lacustrine siltstones, wind (Laity, 2000). HIKE EAST, uphill, to view granitic transgressive shoreline sand, tufa on conglomerate, flat ventifacts. East Cronese Lake lies to the north, and West pebble (shingle) beach bar, ponded back bay, terraces de- Cronese Lake is further north through the pass. These veloped on the Mojave River Formation); fluvial features “twin lakes” were on an alternate route used by emigrants (incised meander, meander terraces, stream channels, flu- (Lyman and Walker, 1999) traveling south from Bitter vial sand and gravel); groundwater discharge platform (un- Springs through Cronese lakes to “the caves” and the wa- bedded silts, carbonate cemented silts, efflorescent salts); ter in Afton gorge. Use of the area by Native Americans is playa features (tan, laminated silts, mud cracks and rip-up well documented (Warren and Schneider, 2000). Return to clasts, cross-playa channels). Discussion will attempt to vehicles and proceed south to the sand fields of the Mojave determine why the deposits are separate and distinct. River Sink. 0.0 (0.0) Convene in central Baker at the intersection of 16.8 (0.7) Pass a BLM kiosk. Highway 127. Start with a full tank of gas for the 100- 18.0 (1.2) Take the left fork in the road. mile day. Enter I-15 and proceed west to the Basin Road offramp. 20.4 (2.4) Bear right. 6.1 (6.1) Pass Zzyzx Road. 20.9 (0.5) TURN LEFT (south) at the intersection on the north side of the tracks. The road bends south and then 11.9 (5.8) Pass Razor Road. west, parallel to the tracks. 3 Desert Symposium 2003 21.3 (0.4) Enter “Afton Canyon Natural Area” (BLM er Formation (Bortugno and Spitler, 1986), in turn overlain sign). by sediments of Lake Manix. Eastward, you can see the 21.4 (0.1) Cross the river and TURN LEFT (west) on the mouth of a tributary canyon incised into dark reddish- north side of the river parallel to the railroad tracks. brown and gray crystalline bedrock. This canyon leads into the bay behind North Afton Beach Ridge and Shoreline 22.0 (0.6) Pass the site of the box car (Reynolds et al., Hill. Its deep incision into solid bedrock has occurred since 2000) buried in place by the railroad. The boxcar does not Lake Manix drained about 18 ka (Meek, 1999). sit on buried tracks. The railroad bridges have 1926 and 1928 dates, and are similar to the 1905 grade. Photographs Notice how the Mojave River forms a large incised of the 1938 flood do not show a box car in the river chan- meander as it passes beneath the trestle and then travels nel. The rate of decomposition since 1985 suggests that the to the south around the large bedrock ridge blocking its box car could not have been in the channel for many years. path. Incised meanders are an unusual landform; another meander occurs at the “Big Bend” of the Mojave River 22.9 (0.9) PARK at Bridge No. 194.65, dated 1928. twelve miles upstream. An incised meander indicates that STOP 1.2. Slot Canyon. This slot canyon suggests that the course of the river was predetermined by subsurface rapid incision has occurred during the formation of Afton structures. The cause of this meander may be related to po- Canyon. The topography (Cave Mtn 15’ quad) suggests sitions of beach ridges that no longer exists (Blackwelder that overflow from Lake Manix could have occurred at and Ellsworth, 1936). When the lake basin was breached, locations below 1800’ both north and south of the present the initial outflows were diverted around the beach ridge, Afton Canyon. This tributary has incised in response to the and the subsequent incision trapped the river in a mean- rapidly lowered base level of Afton Canyon. The verti- dering channel. Although the beach ridge has completely cal incision of antecedent streams draining Lake Manix eroded away,