- GeoRef, Copyright 2008, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
Three main zones of clay pebbles are distinguished among occurrences along the China Sea coast of northeastern Johore, Malaya. One is developed at a storm tide mark, another at the high tide mark, and a third migrates between the clay exposure and the high tide mark. The pebbles are derived from exposed clay sheets alternating with sand layers. Tidal flat conditions and a humid tropical climate favor the formation of the pebbles.