Editing Polystrate fossil (section)

===Quaternary examples===
Scientists interpret ''polystrate fossils'' as fossils buried in a geologically short time span - either by one large depositional event or by several smaller ones. Geologists see no need to invoke a global flood to explain upright fossils. This position of geologists is supported by numerous documented examples, a few of which are discussed in the paragraphs below, of buried upright tree-trunks that have been observed buried in the Holocene volcanic deposits of [[Mount St. Helens]], [[Skamania County, Washington]], and Mount Pinatubo, Philippines; in the deltaic and fluvial sediments of the [[Mississippi River Delta]]; and in glacial deposits within the midwestern United States. These buried upright trees demonstrate that conventional geologic processes are capable of burying and preserving trees in an upright position such that in time, they will become fossilized.<ref name="DiMichele+2011a"/><ref name="KaroweOthers1987a)">Karowe, A.L. and T.H. Jefferson, 1987, ''Burial of trees by eruptions of Mount St. Helens, Washington: Implications for the interpretation of fossil forests'', Geological Magazine 124(3):191-204.</ref>

====Volcanic deposits====
At this time, the best documented occurrences of unfossilized buried upright trees occur within the historic and late-Holocene volcanic deposits of Mount St. Helens (Skamania County, Washington) and of Mount Pinatubo in the Philippines. At Mount St. Helens, both unfossilized and partially fossilized trees have occurred in many outcrops of volcanic debris and mud flows (lahars) and pyroclastic flow deposits, which date from 1885 to over 30,000 BP., along the South Toutle and other rivers. Late Holocene forests of upright trees also occur within the volcanic deposits of other [[Cascade Range]] volcanoes.<ref name="KaroweOthers1987a)"/><ref name="KaroweOthers1995a">Yamaguchi, D.K., and R.P. Hoblitt, 1995, ''Tree-ring dating of pre-1980 volcanic flowage deposits at Mount St. Helens, Washington'', Geological Society of America Bulletin 107(9):1077-1093.</ref> In the space of a few years after the eruption of [[Mount Pinatubo]] in 1991, the erosion of loose pyroclastic deposits covering the slopes of the mountain generated a series of volcanic lahars, which ultimately buried large parts of the countryside along major streams draining these slopes beneath several meters of volcanic sediments. The repeated deposition of sediments by volcanic lahars and by sediment-filled rivers not only created innumerable polystrate trees, but also "polystrate" telephone-poles, churches, and houses, over a period a few years.<ref name=newhall /> The volcanic deposits enclosing modern upright trees are often virtually identical in their sedimentary structures, external and internal layering, texture, buried soils, and other general character to the volcanic deposits containing the Yellowstone buried forests. As in case of modern forests buried by lahars, the individual buried forests of the Yellowstone Petrified Forest and the layers containing them are very limited in their areal extent.<ref name="Amidon, L. 1997"/><ref name="Retallack1981"/>

====Deltaic deposits====
Within excavations for [[Interstate Highway 10]] in the United States of America, and in [[borrow pit]]s, in landfills, and archaeological surveys, unfossilized upright trees have been found buried within late Holocene, even historic, [[fluvial]] and [[River delta|deltaic]] sediments underlying the surface of the [[Mississippi River Delta]] and the [[Atchafalaya Basin]] of [[Louisiana]]. In one case, borrow pits dug in the natural levees of [[Bayou Teche]] near [[Patterson, Louisiana]], have exposed completely buried, 4 to 6 feet (1.2 to 1.8 meters) high, upright trunks of [[Taxodium|cypress]] trees. Northeast of [[Donaldsonville, Louisiana]], a borrow pit excavated for fill used to maintain nearby artificial levees, exposed three levels of rooted upright tree trunks stacked on top of each other lying completely buried beneath the surface of Point Houmas, a patch of floodplain lying within a meander loop of the current course of the Mississippi River.<ref>Heinrich, P.V., 2002, ''Buried forest provide clues to the past'', Louisiana Geological Survey News 12(2):1</ref><ref>Heinrich, P.V., 2005, ''Significance of buried forests exposed in the Lemannville cutoff road pit, St. James, Louisiana.'' Louisiana Geological Survey News 15(2):8-9.</ref>  While searching for buried archaeological sites, archaeologists excavated a 12&nbsp;ft (3.6 meter) high upright rooted cypress tree completely buried within a natural levee of the [[Atchafalaya River]] within the Indian Bayou Wildlife Management Area just south of [[Krotz Springs, Louisiana]]. Radiocarbon dates and historic documents collected for this archaeological survey, during which this and other upright trees were found, of the Indian Bayou Wildlife Management Area demonstrated that these upright trees were buried in the 1800s, during the initial diversion of [[Mississippi River]]'s flow into the Atchafalaya River.<ref>Godzinski, M., R. Smith, B. Maygarden, E. Landrum, J. Lorenzo, J.-K, Yakubik, and M.E. Weed, 2005, ''Cultural Resources Investigations of Public Access Lands in the Atchafalaya Basin Floodway, Indian Bayou South Project Area, St. Landry and St. Martin Parishes, Louisiana''. Report submitted by Earth Search, Inc., New Orleans to the U.S. Army Corps of Engineers under contract number DACW29-02-D-0005, Delivery Order 05</ref>

====Glacial deposits====
Unfossilized, late [[Pleistocene]] upright trees have been found buried beneath [[glacial deposit]]s within North America along the southern edge of the [[Laurentide Ice Sheet]]. These buried forests were created when the southern edge of the Laurentide Ice Sheet locally dammed valleys. As a result, meltwater lakes filled these valleys and submerged forests within them. Sediments released by the melting of the adjacent ice sheet rapidly filled these lakes, which quickly buried and preserved the submerged forests lying within them. One forest of ''in situ'', 24,000-year-old unfossilized upright trees was exposed by excavations for a quarry near [[Charleston, Illinois]].<ref>Hansel, A.K., R.C. Berg, A.C. Phillips, and V. Gutowski, 1999, ''Glacial Sediments, Landforms, Paleosols, and a 20,000-Year-Old Forest Bed in East-Central Illinois'', Guidebook 26. Illinois State Geological Survey.</ref>  Excavations for a tailings pond about [[Marquette, Michigan]], exposed an ''in situ'' forest of unfossilized trees, which are about 10,000 years old, buried in glacial lake and stream sediments.<ref>Pregitzer, K.S., D.D. Reed, T.J., Bornhorst, D.R. Foster, G.D. Mroz, J.S. Mclachlan, P.E. Laks, D.D. Stokke, P.E. Martin, and S.E. Brown, 2000, ''A buried spruce forest provides evidence at the stand and landscape scale for the effects of environment on vegetation at the Pleistocene/Holocene boundary". Journal of Ecology 88(1):45-53
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Illustrated articles about unfossilized upright trees found within glacial deposits of North America include： (1.) [http://www.museum.state.il.us/muslink/forest/htmls/how_bury.html ''How Do We Know?:Buried Forests'']; (2.) [http://www.admin.mtu.edu/urel/breaking/2000/forest.html ''Researchers Study 10,000-Year-Old Buried Forest'']; and (3.) [http://www.geo.msu.edu/geogmich/chippewa.html ''Glacial Lake Chippewa and Stanley''].
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