Editing Polystrate fossil (section)

===Formation by Carboniferous deglacial meltwater-pulses===
In addition, part of the Carboniferous Period was a period of extensive and thick continental [[ice sheet]]s. During the Carboniferous ice age, the repeated [[Glacial period|glacial]] – [[interglacial]] cycles caused major changes in the thickness and extent of continental ice sheets. When these ice sheets expanded in extent and thickness, [[eustatic sea level]] typically fell by over {{convert|100|m|ft|sp=us}}. When these ice sheets shrank in extent and thickness, eustatic sea level typically rose again by typically over {{convert|100|m|ft|sp=us}}.<ref name="Heckel1986a">Heckel, P.H., 1986. ''Sea-level curve for Pennsylvanian eustatic marine transgressive-regressive depositional cycles along midcontinent outcrop belt, North America.'' Geology, 14(4), pp.330-334.</ref><ref name="VeerversOthers1987a">Veervers, J.T. and Powell, C.M., 1987. ''Late Paleozoic glacial episodes in Gondwanaland reflected in transgressive-regressive depositional sequences in Euramerica.'' Geological Society of America Bulletin, 98(4), pp.475-487.</ref> As occurred during the [[Holocene]] Epoch for [[Meltwater pulse 1A]] and [[Meltwater pulse 1B]],<ref name="Gornitz2009a">Gornitz, V., 2009. ''Sea level change, post-glacial.'' In ''Encyclopedia of paleoclimatology and ancient environments''  (pp. 887-893). Springer Netherlands. In: Encyclopedia of paleoclimatology and ancient environments (Ed. V. Gornitz) pp. 887–893. Springer, Dordrecht, The Netherlands.</ref> brief episodes of rapid melting of Carboniferous, Gondwanan continental ice sheets likely caused very rapid rises in sea level that would have abruptly inundated low-lying coastal swamps and drowned the forests growing on them. Based on the sedimentology of roof strata of surface and underground coal mines and cyclothems containing the fossils of upright and ''[[in situ]]'' tree trunks, geologists proposed that the flooding of coastal swamp by [[Deglaciation|deglacial]] [[meltwater]] pulses resulted in the rapid flooding of coastal forests, particularly along preexisting coastal rivers and streams, over large areas of coastal swamp. During and after their submergence, upright trunks of drowned coastal forests were buried by tidally influenced sedimentation.<ref name="ArcherOthers2016a"/><ref name="CecilOthers2014a">Cecil, C.B., DiMichele, W.A. and Elrick, S.D., 2014. ''Middle and Late Pennsylvanian cyclothems, American Midcontinent: Ice-age environmental changes and terrestrial biotic dynamics.'' Comptes Rendus Geoscience, 346(7), pp.159-168.</ref>