Bivalves as bathymetric indicators

摘要: Abstract Water depth does not directly control the distribution of marine bivalve molluscs, but bathymetric inferences may sometimes be made by relating water to environmental variables known limit distribution, such as temperature, salinity, and nature substratum. When contemporaneous stenothermal eurythermal (or stenohaline euryhaline) associations are found in same general area , more tolerant (eurythermal or will usually shallower than less (stenothermal stenohaline) associations. Similarly, dominated epifaunal boring bivalves would normally expected relatively shallow where hard substrata most abundant. Burrowing infaunal present at all depths, deposit-feeding common subtidal, quiet muds. Observations on Recent benthonic suggest that organisms adapted for deep vertical burrowing only intertidal subtidal environments stress conditions sediment-water interface severe. In contrast, horizontal just below sediment surface predominate deeper environments. situ fossil these two modes should therefore reliable indicators relative depth. These patterns also determined from biogenic sedimentary structures, thus this paleobathymetric tool applied many unfossiliferous rocks.