Polystrate fossil: Difference between revisions

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===Yellowstone===

The upright fossil trees of the Gallatin Petrified Forest in the [[Gallatin Range]] and the Yellowstone Petrified Forest at [[Amethyst Mountain]] and [[Specimen Ridge]] in [[Yellowstone National Park]], occur buried within the [[lahar]]s and other volcanic deposits comprising the [[Eocene]] Lamar River Formation as the result of periods of rapid sedimentation associated with explosive volcanism. This type of volcanism generates and deposits large quantities of loose volcanic material as a blanket over the slope of a [[volcano]], as happened during the 1991 eruption of [[Mount Pinatubo]]. Both during and for years after a period of volcanism, lahars and normal stream activity wash this loose volcanic material downslope. These processes result in the rapid burial of large areas of the surrounding countryside beneath several meters of sediment, as directly observed during the 1991 eruption of Mount Pinatubo.<ref name=newhall>Newhall, C.G., and R.S. Punongbayan, 1996, ''Fire and Mud: Eruptions and Lahars of Mount Pinatubo, Philippines'', University of Washington Press. {{ISBN |0-295-97585-7}}</ref> As with modern lahar deposits, the sedimentary layers containing upright trees of the Yellowstone petrified forest are discontinuous and very limited in areal extent. Individual layers containing upright trees and individual buried forests occupy only a very small fraction of the total area of Yellowstone National Park.<ref name="Amidon, L. 1997">Amidon, L., 1997, ''Paleoclimate Study of Eocene Fossil Woods and Associated Paleosols from the Gallatin Petrified Forest, Gallatin National Forest, SW Montana''. unpublished Master's thesis, University of Montana.</ref>

===Fossil soils===

Geologists have recognized innumerable [[fossil soil]]s ([[paleosol]]s) throughout the strata containing upright fossils at Joggins in Nova Scotia, in the Yellowstone petrified forests, in the coal mines of the [[Black Warrior Basin]] of [[Alabama]], and at many other locations. The layer immediately underlying [[coal seam]]s, often called either "[[seatearth]]" or "[[underclay]]", typically either consists of or contains a paleosol. Paleosols are soils which were formed by [[subaerial]] [[weathering]] during periods of very slow or no accumulation of sediments. Later, renewed sedimentation buried these soils to create paleosols. These paleosols are identified on the basis of the presence of structures and microstructures unique to soils; animal burrows and molds of plant roots of various sizes and types; recognizable soil-profile development; and alteration of minerals by soil processes. In many cases, these paleosols are virtually identical to modern soils.

Geologists who have long studied upright fossils found in sedimentary rocks exposed in various outcrops for decades. have described the upright fossil trees as being deeply rooted in place and typically rooted in recognizable [[paleosol]]s. This is in sharp contrast to the claims made by creationists such as Harold Coffin and N. A. Rupke. Geologists, such as Falcon<ref>Falcon-Lang, H.J., 2003a, ''Late Carboniferous dryland tropical vegetation, Joggins, Nova Scotia, Canada'', Palaios 18:197– 211.</ref><ref>Falcon-Lang, H.J., 2003b, ''Early Mississippian lycopsid forests in a delta-plain setting at Norton, near Sussex, New Brunswick, Canada'', Journal of the Geological Society, London 161:969–981.</ref><ref name=falcon2005>Falcon-Lang, H.J., 2005, ''Small cordaitalean trees in a marine-influenced coastal habitat in the Pennsylvanian Joggins Formation, Nova Scotia'', Journal of the Geological Society 162(3): 485-500.</ref><ref name=falcon2006a>Falcon-Lang, H.J., 2006a, ''Latest Mid-Pennsylvanian tree-fern forests in retrograding coastal plain deposits, Sydney Mines Formation, Nova Scotia, Canada'', Journal of the Geological Society 163(1): 81-93.</ref><ref name=falcon2006b>Falcon-Lang, H.J., 2006b, ''Vegetation ecology of Early Pennsylvanian alluvial fan and piedmont environments in southern New Brunswick, Canada'', Palaeogeography, Palaeoclimatology, Palaeoecology 233(1-2): 34-50.</ref> and Rygel et al.,<ref>Rygel, M.C., M.R. Gibling, and J.H. Calder, 2004, ''[[Vegetation-induced sedimentary structures]] from fossil forests in the Pennsylvanian Joggins Formation, Nova Scotia'', Sedimentology 51:531– 552.</ref> have published detailed field-sketches and pictures of upright tree-fossils with intact root systems, which are rooted within recognizable paleosols. In the case of the upright fossil trees of the [[Yellowstone National Park|Yellowstone]] petrified forests, geologists – again in sharp disagreement with creationists like Harold Coffin – found that the upright fossil trees, except for relatively short stumps, are rooted in place within the underlying sediments. Typically, the sediments within which trees are rooted have paleosols developed within them.<ref name="Amidon, L. 1997"/><ref name=Retallack1981>Retallack, G.J., 1981, ''Reinterpretation of the depositional environment of Yellowstone fossil forest: Comment'', Geology 9:52-53.</ref><ref name=Retallack1997>Retallack, G.J., 1997, ''A Colour Guide to Paleosols.'' John Wiley and Sons. {{ISBN |0-471-96711-4}}</ref> Retallack (1981, 1997) has published pictures and diagrams of the Yellowstone upright fossil trees having intact root systems developed within paleosols found within these strata.<ref name=Retallack1981 /><ref name=Retallack1997 /><ref>Since 1997, geologists agree with Harold Coffin that his "organic levels" are not paleosols. Neither Harold Coffin nor other creationists discuss the layers which geologists currently recognize as being paleosols in their papers about the Yellowstone petrified forests. Geologists such as Amidon (1997) have documented the presence of structures, microstructures, profile development, and mineralogical alteration either characteristic or of consistent with a buried-soil profile within numerous thin layers, which are identified as paleosols, found within the strata containing Yellowstone petrified forests</ref>

===Formation by regeneration===