| Abstract:The Circum-Pacific region is one of the most important gigantic skarn-metallogenic belts in the world. In more than 20 coastwise countries of this region, there exist thousands of skarn deposits of different types. According to the differences in major metallic elements, the skarn deposits may be classified into seven subtypes, i.e., iron, copper, lead, zinc, tungsten, tin, molybdenum and gold skarn deposits. In this paper, the distribution and geological characteristics of the above-mentioned types of skarn deposits are described briefly. Skarn deposits may also be classified on the basis of the dominant calc(magnesian)-silicate mineral assemblages into four types, i. e., magnesian, calcic, manganoan, and alkaline skarn types. Magnesian skarns may be associated with iron, copper, gold, tin, boron and beryllinm mineralizations, calcic skarns are concerned with iron, copper, tungsten, molybdenum, gold, beryllium, lead, zinc and tin mineralizations, manganoan skarns are only related to lead and zinc(silver) mineralizations, and alkaline skarns occur together with uranium(thorium, niobium)deposits. Although skarn deposits along both east and west Pacific rims have many general characteristics, they show some differences in geotectonic setting, mineralization intensity, distribution and metallogenic epoch. In this paper, ore-forming series and metallogenic specialization of magmatic rocks related to skarn deposits are also discussed. |
