Abstract:

Skarn has been scientifically recognized as a distinct class of rock for more than 100 years. However, the definition
of skarn is loose. Recently, mineralogy was proposed to be the key to define a skarn: a mineral assemblage including a wide
variety of calc-silicate and associated minerals, but is usually dominated by garnet and pyroxene; it was formed in almost all ages
and a variety of tectonic settings. This pure“ descriptive” definition is not genetic and does not account for processes such as
“metasomatism” and “ replacement”. As for the genetic aspect, diverse models have been proposed: from a general dictionary
definition of contact metamorphic-metasomatic interactions with intruding granitic magma in early times to interactions with maficultramafic
magma and high temperature magmatic skarn in recent years. It seems that genetic geological domain of skarn could be
controversial and is also expanding with time. Melt inclusion in skarn minerals and assimilation experiments studies provides new
insight on the skarn. Skarn-related iron deposits are of the most abundant types among the others, which may reach 5000 Mt with
a grade of 45%. Skarn-related iron deposits are mostly associated with mafic-ultramafic magmatism, alkaline alteration extensively
developed, and were low in Au compared to IOCG. These deposits of Precambrian age are rare. This paper also summarizes some
features of skarn-related iron deposits which promote our understanding of different iron ore deposits. In addition, the skarnization
processes in Yamansu skarn deposit were illustrated.

Key words: skarn, skarn-related deposit, metasomatic rock, metamorphic rock, magmatic skarn, Yamansu skarn-related deposit