Ilmenite deposits showing zonal distribution are developed along Precambrian anorthosite complex in the Hadong-Sancheong area in the southern part of Korea. The massif-type anorthositic rocks in the Jirisan gneiss complex comprise elongate body (about 2~3 km x 25 km) in N-S direction. They show gradual zonation of massive, intercumulated and foliated types from margin to inside, which are classified into anorthosite (massive), leuconorite (foliated) and gabbroic norite (intercumulated) based on the mineral compositions. Ilmenite deposits mainly occur in the zone of intercumulated anorthosite (leuconorite) from Duyang-ri in north to Jikjeon-ri in south.
Jikjeon-ri orebodies whose outcrops show various extension between 1.9 and 20 m in length are located in southern part of ilmenite deposits. They are related by various intrusive rocks including diorite. Drilling cores indicate dikes with wide compositions from granitoid felsic to fine-grained mafic are found in orebodies. Field work and drilling exploration reveal that Ti-rich main orebodies are developed in NW-SE direction with extension of minor vein and veinlets in N-S direction, showing dipping westward below the ground. Ore minerals mainly consist of ilmenite, amphibole, and plagioclase. Accessary minerals are quartz, apatite, chlorite, magnetite, and rutile. Fine grained plagioclase or amphibole are filled in the crack of plagioclase (labradorite) megacrysts. Amphiboles as main constituent of matrix are ferrohornblende (<1mm) or ferropagasite (>1mm) in composition. Ilmenite is closely associated with amphiboles and apatite, filling interstitial spaces of amphiboles and apatite. The chemistry of ores like gabbronorite indicates low in SiO2 and Al2O3, wheres high in Fe2O3, MgO, TiO2, and P2O5 compared to anorthosite, implying formation from more differentiated magma than primitive magma for anorthosite. The variations of major elements shows increasing of Fe2O3, TiO2, P2O5 contents and decreasing of Al2O3 as increasing SiO2 content. This indicates similar trends with the differentiated rock from ferrodioritic magma. Anorthosite first formed by fractional crystallization of plagioclase from primitive basaltic magma and leuconorite formed later during further diffrentiation. Then more diffrentiated magma evolved into Fe-Ti-P concentrated ferrodioritic magma which assume to be the parental magma for deposition of ilmenite ores in Hadong area. Results of 3D-modeling, Ilmenite ore bodies show NW strike and W and/or NE dipping in Jikjeon-ri. Ore bodies display vein type with tabular or lenticular in shape. The measured resources in study area is estimated about 250,000 tons of TiO2.