Open File 2001-12(D) (also known as GSC Open File 4016) represents the second in a series of re-formatted Yukon National Geochemical Reconnaissance Open Files. Data were originally released in 1982 as GSC Open File 868. Re-analysis by INAA was carried out and released in 1999 as GSC Open File D3772. This is a CD-ROM of stream sediment and water geochemistry data for the Nahanni Map area. The following analyses were completed on stream sediments:: Ag, As, Au, Ba, Br, Cd, Ce, Co, Cr, Cs, Cu, Eu, F, Fe, Hf, Hg, La, Loss-on-ignition, Lu, Mn, Mo, Na, Ni, P2O5, Pb, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, V,W, Yb, and Zn. Stream waters were analyzed for:: total alkalinity, Ca, Cl, F, Fe, K, Mg, Mn, Na, Nitrate, pH, phosphate, sulphate, U, and Zn.