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Patagonia, South America
Introduction
Patagonia, a large plateau in southern Argentina, is home to vast expanses of Jurassic, Cretaceous, and Tertiary-aged fossil deposits (Derbach, 1996). Time and again large, forested, areas were overwhelmed by volcanic tuff, which entombed trees and cones. The volcanic tuff acted as a silica source helping to create beautifully preserved permineralized wood and cones. Two sites, Santa Cruz and Chubut, are particularly important to both scientists and collectors interested in well-preserved conifer cones.
In the province of Santa Cruz the Cerro Cuadrado Petrified Forest produces various coniferous woods with Araucaria-like being most common, Araucaria mirabilis conifer cones and Pararaucaria patagonica cones associated with the family Taxodiaceae are also found at this location.
The petrified forest of Cerro Cuadrado is underlaid by an Upper Triassic rock unit and overlaid by Upper Cretaceous strata. Sediments that seem to be associated with the tuffs that contain the wood and cones possess Jurassic aged vegetation. This geologic evidence suggests that the wood and cones from this forest grew during the Middle to Upper Jurassic period (Dernbach, 1992). Many of the Araucaria mirabilis cones exhibit excellent cellular detail with embryos visible in some of the seeds. Scientific studies of Araucaria mirabilis tissue organization indicate that these cones are closely related to the present day Araucaria bidwillii (Derbach, 2002).
Back to Patagonia, South America
Bibliography
Introduction
Patagonia, a large plateau in southern Argentina, is home to vast expanses of Jurassic, Cretaceous, and Tertiary-aged fossil deposits (Derbach, 1996). Time and again large, forested, areas were overwhelmed by volcanic tuff, which entombed trees and cones. The volcanic tuff acted as a silica source helping to create beautifully preserved permineralized wood and cones. Two sites, Santa Cruz and Chubut, are particularly important to both scientists and collectors interested in well-preserved conifer cones.
In the province of Santa Cruz the Cerro Cuadrado Petrified Forest produces various coniferous woods with Araucaria-like being most common, Araucaria mirabilis conifer cones and Pararaucaria patagonica cones associated with the family Taxodiaceae are also found at this location.
The petrified forest of Cerro Cuadrado is underlaid by an Upper Triassic rock unit and overlaid by Upper Cretaceous strata. Sediments that seem to be associated with the tuffs that contain the wood and cones possess Jurassic aged vegetation. This geologic evidence suggests that the wood and cones from this forest grew during the Middle to Upper Jurassic period (Dernbach, 1992). Many of the Araucaria mirabilis cones exhibit excellent cellular detail with embryos visible in some of the seeds. Scientific studies of Araucaria mirabilis tissue organization indicate that these cones are closely related to the present day Araucaria bidwillii (Derbach, 2002).
Back to Patagonia, South America
Bibliography
Dernbach, U. and Tidwell, W.D. 2002. Secrets of Petrified Plants: Fascination from Millions of Years. D’ORO: Germany.
Dernbach, U. 1996. Petrified Forests: The World’s 31 Most Beautiful Petrified Forests. D’ORO: Germany.
Dernbach, U. 1992. Araucaria. D’ORO: Germany