|
|
 |
|||||||||||||||||
|
|||||||||||||||||
 |
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
1 Département de Géosciences, Géologie et Paléontologie, Université de Fribourg, Pérolles, CH-1700 Fribourg, Switzerland
Distinct parts of limestones within the upper Paleozoic Auernig Group of the Carnic Alps, Austria and Italy, are characteristic of cool-water carbonates. The Carnic Alps were between 5°N and 10°S paleolatitude during the late Carboniferous, a position confirmed by dasyclad algae and fossil plants. The floral association, occurrence of coal seams, and absence of evaporites indicate a humid tropical environment. The entire section lacks abiotic components of typical warm-water limestones: no ooids and no aggregates occur within the Auernig Group. Parts of the limestones show, surprisingly, a cool-water association of high-diversity bryozoans, brachiopods, crinoids, red algae, sponge spicules, and entomozoan ostracodes. The genesis of these limestones, atypical for a paleoequatorial setting, cannot be explained by changes in salinity, bathymetry, or terrigenous input. The water temperature, possibly linked with upwelling, nutrient supply, and paleoceanographic currents, is the most convincing cause of this unusual association. Paleoceanographic changes are interpreted as linked to contemporaneous glaciation-deglaciation cycles in Gondwana. This paper shows that cool-water carbonates in shallow-water environments are not necessarily nontropical, as generally interpreted. Future studies should consider water temperature, oceanic circulation, and availability of nutrients, supplementary to bathymetry, salinity, and latitude-related climate in interpretation of carbonate components.
Key Words: cool-water carbonates • cyclothems • paleoceanography • Pennsylvanian • Carnic Alps
This article has been cited by other articles:
|
|
 |
|
  G. S. Soreghan, M. J. Soreghan, C. J. Poulsen, R. A. Young, C. F. Eble, D. E. Sweet, and O. C. Davogustto Anomalous cold in the Pangaean tropics Geology, August 1, 2008; 36(8): 659 - 662. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Van Der Kooij, A. Immenhauser, T. Steuber, M. Hagmaier, J. R. Bahamonde, E. Samankassou, and O. Merino Tome Marine Red Staining of a Pennsylvanian Carbonate Slope: Environmental and Oceanographic Significance Journal of Sedimentary Research, December 1, 2007; 77(12): 1026 - 1045. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Songzhu, F. Qinglai, and H. Weihong The last Permian deep-water fauna: Latest Changhsingian small foraminifers from southwestern Guangxi, South China Micropaleontology, July 1, 2007; 53(4): 311 - 330. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. E. Buitron-Sanchez, C. Gomez-Espinosa, E. Almazan-Vazquez, and D. Vachard A late Atokan regional encrinite (early late Moscovian, Middle Pennsylvanian) in the Sierra Agua Verde, Sonora state, NW Mexico Geological Society, London, Special Publications, January 1, 2007; 275(1): 201 - 209. [Abstract] [PDF]
|
|
|
|
|
|
M. Pedley and G. Carannante Cool-water carbonate ramps: a review Geological Society, London, Special Publications, January 1, 2006; 255(1): 1 - 9. [Abstract] [PDF]
|
|
|
|
|
|
J. Halfar, L. Godinez-Orta, M. Mutti, J. E. Valdez-Holguin, and J. M. Borges Nutrient and temperature controls on modern carbonate production: An example from the Gulf of California, Mexico Geology, March 1, 2004; 32(3): 213 - 216. [Abstract] [Full Text] [PDF]
|
|
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
