This includes data from six sites in Ong Valley where a field party led by Putkonen collected sediment from shallow (~1 m) pits in unconsolidated glacial sediment. Pure quartz separates were subsequently extracted from these samples by sieving, heavy liquid and magnetic separation, and differential etching in dilute hydrofluoric acid. Cosmogenic Ne-21 measurements were made at BGC in May and June 2013.
1. Details of cosmogenic Ne-21 measurements at BGC can be found in the following reference:
Balco, G. Shuster, D.L., 2009. Production rate of cosmogenic Ne-21 in quartz estimated from Be-10, Al-26 and Ne-21 concentrations in slowly eroding Antarctic bedrock surfaces. Earth and Planetary Science Letters 281, pp. 48-58. PDF Supplementary figures Supplementary table
2. BGC has two mass spectrometer/noble gas extraction systems configured for cosmogenic Ne-21 measurements.These measurements were made on the older of the two (the "MAP II" system, whereas the measurements described in the next sections were made on the newer (the "Ohio" system). The two systems were independently calibrated and there is a small systematic difference between cosmogenic Ne-21 concentrations measured on each system. Measurements of the "CRONUS-A" and "CREU-1" quartz standards described below can be used to correct for this offset.
3. We analysed the "CRONUS-A" quartz standard during the period of these measurements; results are reported with the samples below. A discussion of the interlaboratory reproducibility of Ne-21 concentrations in CRONUS-A appears in this reference:
Vermeesch P., Balco G., Blard P-H., Dunai T.J., Kober F., Niedermann S., Shuster D.L., Strasky S., Stuart F.M., Wieler R., Zimmermann L., 2013 in press. Interlaboratory comparison of cosmogenic Ne-21 in quartz. Quaternary Geochronology. PDF preprint
Complete results of step-degassing Ne-21 measurements (PDF format):
Analyses of CRONUS-A quartz standard
Samples from Ong Valley Pit 1
Samples from Ong Valley Pit 2
Samples from Ong Valley Pit 3
Samples from Ong Valley Pit 6
Samples from Ong Valley Pit 11
Samples from Ong Valley Pit 12
Spreadsheet containing these data with summary information:
Figure showing depth-concentration profiles from all pits: