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Basalt flows provide excellent opportunities for calibration and intercomparison of Quaternary dating methods, remote sensing methods, and rates of geomorphic processes. The immediate motivation for this study was to provide chronology for a blind test of the utility of rock varnish microstratigraphy as an indicator of the age of flow emplacement. Five basaltic eruptive centers in the Mojave Desert of California were sampled for cosmogenic Cl-36 analysis. Multiple samples were taken from most centers and, with one exception, produced good agreement. Assuming a surficial erosion rate of 1 mm/kyr(-1), the flows yielded the following ages: Amboy Crater, 79 +/- 5 ka; Pisgah Crater, 22.5 +/- 1.3 ka; Cima field, I-Cone, 27 1.3 ka; Cima field, A-Cone, 21 +/- 1.6 ka and 11. 5 +/- 1.5 ka; Cima field, flow of unidentified origin, 46 +/- 2 ka. The ages from the Cima I and A cones are in good agreement with previous cosmogenic He-3 dating. Ages from the three previously undated flows are significantly older than previous estimates based on flow appearance. Tanzhou Liu performed varnish microstratigraphic analysis on samples collected from the same sites. His results were submitted for publication without knowledge of the Cl-36 ages. His age estimates agree well with the Cl-36 ages for the three previously undated flows, strongly supporting the validity of varnish microstratigraphy as a chronological correlation tool. (C) 2002 Elsevier Science B.V. All rights reserved.