Editing Pollen core (section)

==Methods==
Cores are obtained from deposits where pollen is likely to have been trapped.  Cores are generally obtained from [[Lake|lacustrine]] sediments and [[peat]] [[bog]]s although soil sediments may also be obtained.  Degradation of the pollen exine and [[bioturbation]] may reduce the quality of the pollen grains and stratigraphy of the core so researchers frequently select locations where the sediments are under [[Hypoxia (environmental)|anaerobic]] conditions.

The cores are then subjected to [[pollen analysis]] by [[palynologist]]s who are able to infer the proportions of major plant types from the concentrations of different pollen types found in the cores.

===Coring equipment===
There are a number of tools used for coring, often with specialized uses:

====Core samplers====
{{main|Core sample}}
* Glew corer:  A gravity corer used for lake surface sediments to capture the water-sediment interface.  Similar to the Kajak-Brinkhurst sampler.
* Brown corer:
* Frozen finger:  A tube is placed into the sediment and then filled with [[liquid nitrogen]] causing the sediment around the tube to freeze solid, preserving fine scale structure.
* Livingstone piston corer:  A long metal tube with a piston at the lower end.  Once the core tube is at the desired depth the piston is released and the barrel can be pushed downwards into the sediment.  Generally used for lake sediments.
* Russian:  A chamber corer used to sample [[peat]]s.

====Grab samplers====
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* Ekman grab sampler:
* Petersen grab:
* Ponar grab: