Geoscience Reference
In-Depth Information
MICROFOSSILS
MEGAFOSSILS
MARINE
TERRESTRIAL/
FLUVIAL/LACUSTRINE
BENTHIC
PLANKTONIC
*
*
*
*
Cainozoic
Cretaceous
Jurassic
Triassic
Permian
Carboniferous
Devonian
Silurian
Ordovician
Cambrian
* Freshwater ostracods, brackish water charophytes, benthic and
freshwater diatoms and benthic conodonts also exist.
Figure A5.5
Biostratigraphically useful groups of organisms. The thick part of the line indicates the interval
where the fossil group is used most extensively. (Modifi ed after Nichols 1999 and Emery and Myers 1996.)
strati-
graphical
column
total
range
biozone
consecutive
range
biozone
partial
range
biozone
assemblage
biozone
acme
biozone
last
appearance
rare
(speciation
event)
boundaries
of example
zone
(speciation
event)
rare
first
appearance
Figure A5.6
The
common zonation
schemes used in
biostratigraphical
correlation. (Modifi ed
after Nichols 1999.)
clay
sand
