Description: From Payne and others (2008):"The ECR 100 tephra shows greatest similarity to tephra from Augustine Volcano, although correlations are imperfect and the data set very small. The age-depth model places the tephra at ca. 2840 cal yr BP. Little is known about the distribution of tephra from Augustine eruptions prior to ca. AD 200 (Begét and Kienle, 1992; Waitt and Begét, in press). The source of the tephra cannot be reliably determined, although an Augustine eruption is tentatively suggested as the most likely based on available evidence. Limited data for the MTR 190 tephra show some similarity to tephras from Redoubt Volcano. The age-depth model places the layer at ca. 8660 cal yr BP; the closest Redoubt eruption to this date has an uncorrected radiocarbon date of 7730+/-150 14C yr BP (7050-6250 cal yr BP). This eruption may be the most likely candidate for the source of this tephra but uncertainties remain."