Changes

[[file:applied-paleontology_fig17-6.png|300px|thumb|{{figure number|2}}Typical diatoms.]]

[[file:applied-paleontology_fig17-6.png|300px|thumb|{{figure number|2}}Typical diatoms.]]

Diatoms are [http://www.merriam-webster.com/medical/photosynthesis photosynthesizing] [http://www.thefreedictionary.com/planktonic protists] that occur in both marine and nonmarine environments. Marine diatoms range from [[Upper Jurassic]] or [[Lower Cretaceous]] to [[Holocene]] and are particularly useful for age and environmental determinations in the upper [[Cenozoic]]. Nonmarine diatoms range from [[Eocene]] to Holocene and also are useful in the upper Cenozoic. These microfossils can be a major rock-forming group, forming sedimentary rock (diatomites) consisting primarily of diatoms. Diatomaceous sediments, when altered by burial diagenesis, are converted to siliceous shale, [http://www.britannica.com/EBchecked/topic/470558/porcellanite porcellanite], and chert. Such rocks can serve as sources and fractured reservoirs for hydrocarbons (e.g.,[[ Monterey Formation]] of California). The changes in rock properties associated with silica diagenesis permit seismic definition of [http://www.quartzpage.de/gen_mod.html silica phase transformation] zones in the subsurface (e.g., [http://wiki.seg.org/wiki/Dictionary:Bottom-simulating_reflector_%28BSR%29 bottom-simulating reflector]).

Diatoms are [http://www.merriam-webster.com/medical/photosynthesis photosynthesizing] [http://www.thefreedictionary.com/planktonic protists] that occur in both marine and nonmarine environments. Marine diatoms range from [[Upper Jurassic]] or [[Lower Cretaceous]] to [[Holocene]] and are particularly useful for age and environmental determinations in the upper [[Cenozoic]]. Nonmarine diatoms range from [[Eocene]] to Holocene and also are useful in the upper [[Cenozoic]]. These microfossils can be a major rock-forming group, forming sedimentary rock (diatomites) consisting primarily of diatoms. Diatomaceous sediments, when altered by burial diagenesis, are converted to siliceous shale, [http://www.britannica.com/EBchecked/topic/470558/porcellanite porcellanite], and [http://geology.com/rocks/chert.shtml chert]. Such rocks can serve as sources and fractured reservoirs for hydrocarbons (e.g.,[[ Monterey Formation]] of California). The changes in rock properties associated with silica diagenesis permit seismic definition of [http://www.quartzpage.de/gen_mod.html silica phase transformation] zones in the subsurface (e.g., [http://wiki.seg.org/wiki/Dictionary:Bottom-simulating_reflector_%28BSR%29 bottom-simulating reflector]).

[[:file:applied-paleontology_fig17-6.png|Figure 2]] shows some typical diatoms.

[[:file:applied-paleontology_fig17-6.png|Figure 2]] shows some typical diatoms.

http://www.britannica.com/EBchecked/topic/470558/porcellanite

http://www.britannica.com/EBchecked/topic/470558/porcellanite

==Silicoflagellates==

==Silicoflagellates==