World Map of Carbonate Rock Outcrops v3.0
The first version of the world map of carbonate rocks appeared in Ford & Williams (1989) Karst Geomorphology and Hydrology. A revision was published in Williams & Ford (2006) Zeitschrift für Geomorphologie Suppl-Vol 147, 1-2, and used in Ford & Williams (2007) Karst Hydrogeology and Geomorphology (Wiley). This v3.0 revision is in greater detail and attempts to differentiate those areas where carbonate rocks are relatively pure and continuous from those where they are abundant but discontinuous or impure. It was prepared by Paul Williams and Yin Ting Fong using a multitude of sources the most important of which are acknowledged in Williams & Ford (2006). The map was assembled using GIS on an Eckert IV equal-area projection.