Ž . Geomorphology 30 1999 357–392 The Lake Lahontan highstand: age, surficial characteristics, soil development, and regional shoreline correlation Kenneth D. Adams ) , Steven G. Wesnousky Center for Neotectonic Studies and Department of Geological Sciences, UniÕersity of NeÕada, Reno, NV, 89557, USA Received 5 March 1998; received in revised form 2 February 1999; accepted 19 February 1999 Abstract The Lake Lahontan basin has been the site of numerous pluvial lakes during the Pleistocene. We address the question of whether or not the highest remnant shoreline features around the perimeter of the lake were produced during the most recent Ž . Ž . Sehoo highstand ;13 ka , the penultimate Eetza highstand ;140–280 ka , or both. To do so, we document surficial characteristics, morphologic preservation, and soil development on multiple Sehoo beach barriers in the Jessup embayment to define the range in characteristics displayed by latest Pleistocene beach features. Sehoo barriers generally exhibit original constructional morphology that has been little modified by erosion. Soils developed on Sehoo barriers are generally thin and weakly developed and are strongly influenced by the introduction of eolian fines into the predominately clast-supported coarse beach gravels. Similar observations from 13 other highstand barriers and from seven older-than-latest Pleistocene paleosols located around the basin form the basis for a regional comparison. Based on similar characteristics, including the degree of morphologic preservation and weak soil development, we conclude that the widespread and nearly continuous high shoreline around the perimeter of Lake Lahontan dates from the most recent major lake cycle in all areas except in the Walker Lake subbasin. In the Walker Lake subbasin, isolated early to middle Pleistocene lacustrine outcrops and landforms are elevated as much as 70 m above the late Pleistocene limit, but are differentiated by their degraded form and lack of continuity around the subbasin. Similar unambiguous landforms were not observed elsewhere and at similar elevations in the northern subbasins of Lake Lahontan. q 1999 Elsevier Science B.V. All rights reserved. Keywords: Lake Lahontan; highstand; soil development; shoreline correlation 1. Introduction Lake Lahontan occupied most of the basins in northwest Nevada and the Honey Lake basin in adjacent northeast California during its last highstand Ž . at about 13 ka Fig. 1 . Well-developed shoreline ) Corresponding author. Quaternary Sciences Center, Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512-1095. Ž . E-mail address: kadams@dri.edu K.D. Adams features and coastal geomorphology displayed on the mountain fronts and piedmonts around the basin attest to vigorous wave energy caused by Pleistocene Ž . storms. The late Pleistocene Sehoo lake was, how- ever, only the most recent in a series of lakes that have occupied the same basin through the Quater- nary. As many as five major lake cycles in the last 1 Ma are identified by lacustrine deposits separated by nonconformities andror weathering horizons and Ž dated by volcanic tephras Davis, 1978; Morrison, . 1991; Reheis, 1996; Reheis and Morrison, 1997 . 0169-555Xr99r$ - see front matter q 1999 Elsevier Science B.V. All rights reserved. Ž . PII: S0169-555X 99 00031-8