In the framework of the work entrusted to WEDEXRO in 1958 "the suitability of the sigihan coal for metallurgical purposes was to be determined" and at the same time "it appeared advisable to carry out a critical examination of the state of the sigihan mine".
pada tahun 1979,proyek inventiarisasi dan eksplorasi batubara telah mulai menyelidiki endapan batubara di alimantan timur,di daerah antara samarinda-balikpapan
In connection with the Agreement concluded with wedexro in March 1956 on the "Investigation into the Geological and Mining Aspects of the Iron-ore and Coal Occurrence in Indonesia" a Supplementary Agreement Was made on July 9, 1958 between the state Planning Bureau in Djakarta-referred to as BPM for short- and Wedexro relating to the investigation o…
The result of the geologi cal and minig investigations on the coal deposits of South-Eastern-Kalimantan have been discussed in the report of the mining engineer Klees (issue 4 vol 3).