In July-August 1993, two ice cores to bedrock were recovered from the col 
between the north and south peaks of Nevado Huascaran, Peru (9S, 77deg30'W, col 
elevation 6050 m) and were subsequently transported back to the cold room facility at the 
Byrd Polar Research Center (BPRC).  Core 1 (HSC1, 160.40 m) was sectioned in the 
field into 2677 samples decreasing in thickness from 13 cm at the top to 3 cm at the base, 
which were then melted and poured into 2 or 4 oz. plastic (HDPE) bottles, and sealed 
with wax.  Core 2 (HSC2, 166.08 m), drilled approximately 100 m from the HSC1 site, 
was returned frozen in 1 m sections.  Ice motion vectors determined from stake 
movements from 1991-93 indicate that the drill sites are proximal to the divide between 
ice flow towards the east and west outlets of the col.  Visible observations and borehole 
temperatures indicate that the glacier is 'polar' type, i.e., it remains frozen to the bed 
(Thompson et al., Science, v.269, 1995, p. 46-50).
	Each ice sample from HSC2 was prepared in a Class 100 clean room 
environment, and analyzed for major anion concentrations (Cl-, NO3-, and SO42-) on a 
Dionex 2010i ion chromatograph, d18O on a Finnigan Mat mass spectrometer (Craig, 
1957), and for particulate concentration and size distribution using a Coulter TA-II 
particle counter (Thompson, OSU IPS Report 46, 1973).  A complete d18O profile was 
also produced from the bottled samples from HSC1.  Contamination during field 
preparation and transport of these samples precluded the development of a second 
complete record of particles and anion concentrations.
	For display purposes, variable averaging on the core depth scale was utilized to 
show the major large-scale events in the record without the confusion of the large annual 
variations superimposed upon the upper portion.  Hence, for HSC2, 5-m integrated 
averages were calculated for between the surface and 140 meters depth and then 50-cm 
averages were generated between 140 and 160 meters.  Between 160 and 166 meters, 
every sample value was plotted.  A similar scheme was used for HSC1 (all values plotted 
for 155-160.4 m).  These data are included in hs12-5m.txt in this data archive, and the 
graph can be seen in Thompson et al., 1995 (Fig. 3).