Electronic Supplement Ð BSSA-D-12-00024 Table S2. Luminescence parameters used in preparation and analyses of samples for quartz OSL Measurement parameters Machine: Automated Ris¿ TL/luminescence-DA-15 Mineral; grain size: Quartz; 250-180 micron or 180-90 micron Stimulation source: Blue LED diodes, emission centered on 470 nm Power delivered to aliquot: 13 mW/cm^2 (90% power) Duration of stimulation: 40 seconds Final signal level: 1% of initial Photomultiplier: Thorn-EMI 9235Q Aliquot temperature: 125 ¡C Detection filters: Two Hoya U340 filters Normalization: none Preheat: 220 ¡C (samples <5 ka) for 10 secs Delay before measurement: 120 sec Equivalent dose evaluation: single aliquot regeneration (Murray and Wintle, 2000) Background evaluation: black body counts <40 ct/sec, BG counts <45 ct/sec Alpha effectiveness: n/a Dose-rate evaluation: lab gamma spectrometer (high resolution Ge) Dose rate range: 1.64-3.67 Gy/ka (average ~2.25 Gy/ka) Water content: 10-25% Cosmic-ray contribution: 40% of total dose rate for some near surface samples, 20- 30% average