CARBONIFEROUS OF NORTHEAST THAILAND - A REVIEW WITH NEW DATA

A synthesis is provided of the many papers published on the Carbonifer ous of northeast Thailand since 1960, which have been restricted to lo calities north of latitude 17 degrees 10'N. In addition, new data are provided on Carboniferous localities recently discovered south of lati tude 17 degrees 10'N. All stages of the Carboniferous are represented in northeast Thailand and their exposures are delimited in this paper. In northeast Thailand, Carboniferous rocks are widely exposed in an a rea where Loei and Wang Saphung are the main towns, an area 20-40 km w ide and 140 km long. In parts of this area, they are overlain by Permi an strata (mainly limestone) in the core of a syncline. Middle-Upper D evonian limestone, shale and chert occur occasionally in the central a nd northern parts of the area. They are less widely distributed than t he Carboniferous rocks but are obvious features because the limestone forms karstic hills and the chert outcrops are prominent.An important development of shale during the Middle-Upper Carboniferous has favoure d differential erosion so that today these rocks are distributed commo nly in flat areas with paddy fields; the shale concealed under a few m eters of earth. Their discovery has been due to farmers digging ponds at several places.