抄録
The Atalaya prospect area is located at latitude 10°01'S, longitude 76°57'W in Ancash Department, Republic of Peru. Compania Minera Santa Luisa S.A., a subsidiary of Mitsui Mining & Smelting Co., Ltd., and Mitsui & Co., Ltd., have been exploring the area occasionally since 1979. The area consists of gently folded Cretaceous sediments and Tertiary intrusive. The zinc mineralization is recognized in the skarn formed in the limestone around the granite porphyry intrusive. Major zinc mineralization is shown in the skarn of the Pariahuanca Formation and the Jumasha Formation around Azulcocha, Minas Punta and Santa Clara. In the present exploration campaign which commenced in 2006, Santa Luisa has undertaken surface mapping, geophysical study and drilling. The drilling program, which began in August, 2007 had finished 34 diamond drillings totaling 9,586m by the end of 2008. As a result, 28 holes intersect more than 5% of zinc, and 9 holes over 50m intersects with zinc mineralization. Broad low-grade zinc mineralization is known to occur over almost entire area. The mineralization is not blocked yet and the still open to north and south extension. The further exploration work is necessary to define characterize the mineralization of the area.