Lake A Ice Pellets

(a) Mean frequency of macroscopic pellets on core faces and thin sections using all cores from 2006 and one core from 2005 (A-02-05). No large pellets were visible below 230 mm in any core. Asterisks (*) indicate large pellets (>1 mm in height) within the section. (b) Mean frequency of the pattern of prominent dark orange laminae overlying laminae with reduced pigmentation and (c) mean percentage of orange or red hued units per marker bed interval from cores A-02-06 to A-11-06 and A-02-05. Bars represent intervals between marker beds. Estimated ages for each marker bed, derived from a varve-based age-depth model, are shown with estimated cumulative error on the left y-axis. (d) Relative iron abundance within the sediments of core A-04-06 expressed as x-ray counts at the iron energy level from ITRAX-XRF analysis. Note the different scaling of estimated ages with depth for (d) on the right y-axis