Generally, these studies note higher concentrations of ENT in dry sand (above the high tide mark, or supratidal zone) and lesser concentrations in wet sand (below high tide mark, or intertidal zone) and underwater sand (subtidal zone).
ENT levels were highest in the supratidal zone, lower in the intratidal zone, and lower still in the subtidal zone.
Combining results across all beaches, the geometric mean concentrations were 2.29 CFU/g (subtidal zone), 2.95 CFU/g (intertidal zone), and 4.15 CFU/g (supratidal zone).
This was identified as the supratidal zone
where carbonate mud-flats were exposed to alternating episodes of wetting and more prolonged drying; hence, this represents a setting above average sea level, assuming a microtidal coast, typical of most epicontinental seas (Allison & Wells 2006).
peruvianus are found in the supratidal zone
within 1 m from the high mean tide level.
In arid tidal flats, such as Persian Gulf sabkha, gypsum precipitates in a transitional zone between intertidal and supratidal conditions, while anhydrite precipitates in the supratidal zone
Abundant specimens of Chaetomorpha linum, and infrequent specimens of Enteromorpha prolifera and Bangia atropurpurea were found mainly in tidepools in the supratidal zone
and in the upper intertidal zones on both sides of the jetty.
Sabkhas are located in supratidal zones
, forming along arid coastlines and are characterised by evaporate-carbonate deposits."
After briefly discussing diagenesis in tidal-flat deposits, the author examines peritidal sediments and facies in shallow subtidal, intertidal, and supratidal zones
. The pitfalls in recognizing peritidal facies are pointed out before moving on to peritidal stratigraphy, cyclic vs.