Concentration levels of the organic acids HCOO- and CH3SO-3, inorganic acids NO-3 and excess SO2-4 and ammonium were measured in pre-1900 AD ice layers from seven geographically dispersed inland sites in Greenland. Average multiple-year background concentration levels are calculated for each ion at each site from laboratory measurements of continuous core samples representing from 4 to 10 years of snow accumulation (32 to 80 individual measurements) from various time intervals. The HCOO- concentration level increases from 6 ng/g in the most northern colder site to 36 ng/g in the most southern warmer site; CH3SO-3 increase from 0.9 ng/g to 2.8 ng/g; NO-3 decreases from 83 ng/g to 37 ng/g; excess SO2-4 decreases from 43 ng/g to 19 ng/g, all with variability. The distribution of the NH+4 ion shows a nearly constant level at about 6 ng/g for all sites except Dye-2 where it reaches 10 ng/g. The deposition patterns for HCOO- and NH+4 on the ice sheet suggest major contributions arrive from sources originating from the southwest of Greenland. ¿ American Geophysical Union 1993