Underclay Un"der*clay`, n. (Geol.) A stratum of clay lying beneath a coal bed, often containing the roots of coal plants, especially the {Stigmaria}. [1913 Webster]

The Collaborative International Dictionary of English. 2000.

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  • Stigmaria — Stig*ma ri*a, n. [NL. See {Stigma}.] (Paleon.) The fossil root stem of a coal plant of the genus {Sigillaria}. [1913 Webster] …   The Collaborative International Dictionary of English

  • Stigmaria — are a type of branching tree root found fossil in Carboniferous rocks. They were the roots of coal forest lycopsid trees such as Sigillaria and Lepidodendron . Each trunk tended to have four of those roots …   Wikipedia

  • Stigmarĭa — Stigmarĭa, s. Lykopodinen …   Meyers Großes Konversations-Lexikon

  • Stigmaria — Stigmarĭa, Pflanzengattg., s. Sigillaria …   Kleines Konversations-Lexikon

  • stigmaria — stig·mar·ia …   English syllables

  • stigmaria — …   Useful english dictionary

  • Polystrate fossil — [ Nova Scotia, Canada (printed 1868).] Polystrate or upright fossil describes fossils of single organisms (such as tree trunks) that run through more than one geological strata. Entire fossil forests have been discovered [… …   Wikipedia

  • Lepidodendrales — Lepidodendron lycopodioides Zeitraum Devon bis Perm Systematik Reich …   Deutsch Wikipedia

  • Steinkohlenformation — (Geogn.), der Inbegriff einer Anzahl neptunischer Gesteinsbildungen, deren Entstehung zwischen die Ablagerung der devonischen Grauwacke u. des Rothliegenden fällt; sie hat ihren Namen von den fast niemals in ihr fehlenden, oft sehr mächtigen… …   Pierer's Universal-Lexikon

  • CARBONIFÈRE — Compris entre le Dévonien et le Permien, le Carbonifère (terme proposé par William Daniel Conybeare en 1822 pour l’ensemble des terrains qui, en Angleterre, renferment de la houille) s’étend sur environ 100 millions d’années (Ma) si l’on y inclut …   Encyclopédie Universelle

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