Changes

Depth is merely the vertical component of the site location relative to sea level—an arbitrarily defined point in space. Unlike temperature or salinity, depth is not a true environmental parameter because it does not directly influence the morphology, distribution, or biological processes of marine organisms. However, foraminifera can help us estimate paleodepth because many environmental factors influencing their distribution (notably ambient light, oxygen, and temperature) change systematically with increasing water depth.

Depth is merely the vertical component of the site location relative to sea level—an arbitrarily defined point in space. Unlike temperature or salinity, depth is not a true environmental parameter because it does not directly influence the morphology, distribution, or biological processes of marine organisms. However, foraminifera can help us estimate paleodepth because many environmental factors influencing their distribution (notably ambient light, oxygen, and temperature) change systematically with increasing water depth.

Modern foraminiferal distributions reflect oceanographic patterns in a glacial world ocean that originated in the middle Miocene; they are less accurate in estimating paleobathymetry for the preglacial early and middle Tertiary. Early Tertiary and Mesozoic oceans were much warmer and less stratified than at present, and accurate paleodepth estimates must be based on recalibrated early Paleogene and Cretaceous distributions (e.g., .<ref name=ch17r81>Sliter, W., V., Baker, R., A., 1972, Cretaceous bathymetric distribution of benthic foraminifers: Journal of Foraminiferal Research, vol. 2, no. 4, p. 167–183., 10., 2113/gsjfr., 2., 4., 167</ref><ref name=ch17r68>Olsson, R., K., Nyong, E., E., 1984, A paleoslope model for Campanian–lower Maestrichtian foraminifera of New Jersey and Delaware: Journal of Foraminiferal Research, vol. 14, no. 1, p. 50–68., 10., 2113/gsjfr., 14., 1., 50</ref>

Modern foraminiferal distributions reflect oceanographic patterns in a glacial world ocean that originated in the middle Miocene; they are less accurate in estimating paleobathymetry for the preglacial early and middle [[Tertiary]]. Early Tertiary and Mesozoic oceans were much warmer and less stratified than at present, and accurate paleodepth estimates must be based on recalibrated early Paleogene and Cretaceous distributions (e.g., .<ref name=ch17r81>Sliter, W., V., Baker, R., A., 1972, Cretaceous bathymetric distribution of benthic foraminifers: Journal of Foraminiferal Research, vol. 2, no. 4, p. 167–183., 10., 2113/gsjfr., 2., 4., 167</ref><ref name=ch17r68>Olsson, R., K., Nyong, E., E., 1984, A paleoslope model for Campanian–lower Maestrichtian foraminifera of New Jersey and Delaware: Journal of Foraminiferal Research, vol. 14, no. 1, p. 50–68., 10., 2113/gsjfr., 14., 1., 50</ref>

==Depth zones==

==Depth zones==