----------------------------Original message---------------------------- Brad Green asks: >What is the datum, ellipsoid, and projection parameters of topographic sheets > for the south western Argentina bordering Chile? The 1988 (Numero 53/54) Revista Cartografica of the Instituto Panamericano de Geografia e Historia describes the Sistemas de Referencias of Argentina. The Campo Inchauspe Datum is based on the International Ellipsoid, with conversion parameters given for WGS-84 and other datums. Hope this incomplete and dated anwser will prompt someone to top it with newer and more complete information. Peter Peter H. Dana - Department of Geography - University of Texas at Austin Austin, Texas 78712-1098 - Tel: (512) 869-1450 - Fax: (512) 869-0899