CARBONATE RAMPS AND THEIR TECTONIC CONTROLS,WITH AN EXAMPLE FROM THE LONGWANGMIAOIAN(EARLY CAMBRIAN)YANGZI CARBONATE RAMP IN SOUTH CHINA

A ramp is a shallow, gently dipping platform (slopes typically less than 1°) that lacks a marked break on slopes.
Controls on the development of the ramps are: (1) stable tectonic settings; (2) thermal subsidence; (3) flexure of the loaded foreland basin, and (4) sea level fluctuations.
The Yangzi ramp was formed on a passive continental margin, and its development was controlled mainly by thermal subsidence. Five distinct geomorpho-sedimentary facies units may be recognized: (1) nearshore tidal flat; (2) shallow-water subtidal ramp; (3) shallow-water ramp buildups; (4) deep-water ramp, and (5) deep-water ramp buildups.