Description: From Fierstein (2007): "The youngest of the 19 ash layers (K-2500N), 19 cm beneath intact 1912 fallout, rests on dark brown organic-rich fine soil dated at 450+/-65 14C year B.P. (Table 2 [in original text]; K-2500Ns). At this location it is a sharply defined 3.5-cm-thick couplet of two sublayers that correlate with the upper grey ash previously described. The couplet probably reflects two pulses of a single eruption, with the finest ash settling between explosive events. As detailed above, this ash may have originated at Mount Peulik, 75 km SW."