Sed.Home | Alph | Intro | BasicClass | QFLClass | Keys | Depo.Envir | Evol | Evol.Model | Sed.Tect | Self Tests
Carbonate Tectonics
     Carbonates of all types are commonly associated with regions of tectonic stability and tropical climates. There are exceptions, so this rule is not absolute.

Tectonic Stability
     The tectonic stability is required to minimize clastic sourcelands and keep out weathering debris (shales and sandstones), which if abundant enough will swamp out carbonate production.
     Tectonic stability is commonly associated with stable continental regions (such as Stage A or Stage D of the Wilson cycle), and most of the carbonates in the world are associated with such regimes. But, there are exceptions. Volcanic islands, both hot spots (e.g. Hawaii) and subduction arcs often have abundant carbonates formed on their flanks, resulting in a strange association of interbedded volcanic rocks and limestones.

Tropical Climates
     Tropical climates seemed to be required for the high organic activity needed to produce the carbonate sediment. Or alternatively, for chemical carbonates (oolites, micrites), high evaporation rates to supersaturate the dissolved carbonate making precipitation easier.
     The necessity of tropical climates has plate tectonic implications since many ancient carbonates are now found in climates too cold for them to have formed. Thus, even if the tectonics are right, carbonates will only form when the continent drifts into tropical regions.

LSF Home | Geology Web Sites | Courses | Geology Home
Last Update: 10/26/00

e-mail: (