Skolithos pipe rock and associated ichnofabrics from the southern Rocky Mountains, Canada: colonization trends and environmental controls in an early Cambrian sand-sheet complex

Authors

  • PATRICIO R. DESJARDINS,

  • M. GABRIELA MÁNGANO,

  • LUIS A. BUATOIS,

  • BRIAN R. PRATT


Patricio R. Desjardins [patricio.desjardins@gmail.com], M. Gabriela Mángano [gabriela.mangano@usask.ca], Luis A. Buatois [luis.buatois@usask.ca] and Brian R. Pratt [brian.pratt@usask.ca], Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK S7N 5E2, Canada; manuscript received on 21/05/2009; manuscript accepted on 02/11/2009.

Abstract

Desjardins, P.R., Mángano, M.G., Buatois, L.A. & Pratt, B.R. 2010: Skolithos pipe rock and associated ichnofabrics from the southern Rocky Mountains, Canada: colonization trends and environmental controls in an early Cambrian sand-sheet complex. Lethaia, 10.1111/j.1502-3931.2009.00214.x

The Lower Cambrian Gog Group of the southern Rocky Mountains of western Canada offers an opportunity to explore animal–sediment relationships in a high-energy setting, during the early phase of Phanerozoic diversification. Its strata record a sand-sheet complex on the broad pericontinental shelf of West Laurentia. Six ichnofabrics are recognized: Skolithos IF-1 characterized by Skolithos linearis in planar cross-stratified sandstone; Skolithos IF-2 with Skolithos linearis and accessory Diplocraterion parallelum in ripple cross-laminated, and planar and trough cross-stratified sandstone; Skolithos IF-3 with S. linearis and Planolites montanus in wavy- and flaser-bedded sandstone, interfingering with bioturbated mudstone exhibiting P. montanus and Teichichnus rectus; Skolithos IF-4, characterized by abundant Skolithos linearis in planar and trough cross-stratified sandstone; Rosselia IF-1 consisting of Rosselia isp. in planar cross-stratified sandstone; and Rosselia IF-2 consisting of scattered small Rosselia isp. in hummocky, cross-stratified sandstone. The presence of contrasting ichnofabrics within a single early Cambrian sand-sheet complex illuminates how the colonization trends of suspension and detritus feeders were controlled by factors specific to the various sub-environments. □Gog Group, Ichnofabric, Lower Cambrian, Pipe Rock, Rosselia, Skolithos.

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