Event Name : Augustine Tephra O
|Start: 1195 (± 120 Years) || Years BP C-14 (raw) || |
|Stop: 710 (± 50 Years) || Years BP C-14 (raw) || |
From Waitt and Beget (2009): "Between tephras C and M a seventh tephra O-rare and in most places missing, its origin and significance obscure-we eventually dropped as a reliable marker bed but it shows in certain measured sections (plate 2 [in original text]). These coarse tephra layers also contain 10 to 40 volume percent lithic andesite fragments smaller than pumice fragments. Isopach maps, drawn from thickness measured mostly at coastal exposures, show the azimuths to which five of the coarse layers drifted (fig. 7 [in original text])."
"The lowest five coarse-pumice beds at the coast-tephras G, I, H, C, and O-drifted east and southeast. Tephra G and ambiguous tephra O are known only from a few sites each on the east and southeast, neither with enough data points to warrant a map."