Cambrian sponge spicules and Chancelloriid sclerites from the Argentine Precordillera: A review
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| Natura: | Artículo científico |
| Lingua: | en |
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Universitat de Barcelona
2003
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| author | M.S. Beresi |
| author_facet | M.S. Beresi |
| contents | Cambrian sponge spicules and Chancelloriid sclerites from the Argentine Precordillera: A review M.S. Beresi Ciencias de la Tierra Mendoza Cambrian San Juan Argentina Precordillera Spicules of sponges and sclerites of chancelloriids have been collected from in situ Cambrian sections of theLa Laja Formation (San Juan Precordillera). They have also been collected from carbonate olistoliths, whichwere emplaced from the Cambrian units in the Early Ordovician Los Sombreros Formation (San Juan Precordillera)and Empozada Formation (Mendoza Precordillera). The Cambrian La Laja Formation sequences weredeposited in a shallow carbonate platform in the eastern part of the Precordillera. The Cambrian carbonate rocks,which make up the olistoliths in the Los Sombreros and Empozada Formations, record deposition in the slopeenvironments which developed in the western Precordillera. Cambrian Porifera and sponge-like chancelloriidassemblages are known mainly from fragments of skeletal nets, dissociated spicules and sclerites, which enableus to define two assemblages. The first assemblage of spicules was defined from the upper Lower to MiddleCambrian sequences of the La Laja Formation. This assemblage consists of a variety of stauractines and scleritesof Chancelloria WALCOTT. The family Protospongiidae is represented by triradiate prodianes, pentactines andhexactines, all belonging to Kiwetinokia WALCOTT. The second assemblage, which consists of isolated hexactines,pentactines, monaxons and skeletal nets, was defined in the Cambrian derived olistholiths of the Los Sombrerosand Empozada Formations. Early hexactinellid Protospongiidae with body preservation (Diagoniella ?and Kiwetinokia) also occur. Demosponges have a very limited record in the Cambrian of the Precordillera. Anthaspidellidsponges had been reported from the La Laja Formation and now from the San Martín olistolith(Empozada Formation). The occurrences of these two assemblages of spicules and sclerites in both the Cambrianplatform and slope facies of the Precordillera contribute additional data for a better understanding of the relationshipsbetween the eastern and the western facies assemblages, which developed in the Precordillera duringthe Cambrian. Therefore, they are useful for paleoenvironmental and paleogeographical interpretations of theCambrian depositional framework. 2003 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50510107 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.1 Vol.1 |
| format | Artículo científico |
| id | redalyc_50510107 |
| institution | Redalyc |
| language | en |
| publishDate | 2003 |
| publisher | Universitat de Barcelona |
| spellingShingle | Cambrian sponge spicules and Chancelloriid sclerites from the Argentine Precordillera: A review M.S. Beresi Ciencias de la Tierra Mendoza Cambrian San Juan Argentina Precordillera Cambrian sponge spicules and Chancelloriid sclerites from the Argentine Precordillera: A review M.S. Beresi Ciencias de la Tierra Mendoza Cambrian San Juan Argentina Precordillera Spicules of sponges and sclerites of chancelloriids have been collected from in situ Cambrian sections of theLa Laja Formation (San Juan Precordillera). They have also been collected from carbonate olistoliths, whichwere emplaced from the Cambrian units in the Early Ordovician Los Sombreros Formation (San Juan Precordillera)and Empozada Formation (Mendoza Precordillera). The Cambrian La Laja Formation sequences weredeposited in a shallow carbonate platform in the eastern part of the Precordillera. The Cambrian carbonate rocks,which make up the olistoliths in the Los Sombreros and Empozada Formations, record deposition in the slopeenvironments which developed in the western Precordillera. Cambrian Porifera and sponge-like chancelloriidassemblages are known mainly from fragments of skeletal nets, dissociated spicules and sclerites, which enableus to define two assemblages. The first assemblage of spicules was defined from the upper Lower to MiddleCambrian sequences of the La Laja Formation. This assemblage consists of a variety of stauractines and scleritesof Chancelloria WALCOTT. The family Protospongiidae is represented by triradiate prodianes, pentactines andhexactines, all belonging to Kiwetinokia WALCOTT. The second assemblage, which consists of isolated hexactines,pentactines, monaxons and skeletal nets, was defined in the Cambrian derived olistholiths of the Los Sombrerosand Empozada Formations. Early hexactinellid Protospongiidae with body preservation (Diagoniella ?and Kiwetinokia) also occur. Demosponges have a very limited record in the Cambrian of the Precordillera. Anthaspidellidsponges had been reported from the La Laja Formation and now from the San Martín olistolith(Empozada Formation). The occurrences of these two assemblages of spicules and sclerites in both the Cambrianplatform and slope facies of the Precordillera contribute additional data for a better understanding of the relationshipsbetween the eastern and the western facies assemblages, which developed in the Precordillera duringthe Cambrian. Therefore, they are useful for paleoenvironmental and paleogeographical interpretations of theCambrian depositional framework. 2003 artículo científico 1695-6133 https://www.redalyc.org/articulo.oa?id=50510107 en http://www.redalyc.org/revista.oa?id=505 Geologica Acta: an international earth science journal application/pdf Universitat de Barcelona Geologica Acta: an international earth science journal (España) Num.1 Vol.1 |
| title | Cambrian sponge spicules and Chancelloriid sclerites from the Argentine Precordillera: A review |
| topic | Ciencias de la Tierra Mendoza Cambrian San Juan Argentina Precordillera |
| url | https://www.redalyc.org/articulo.oa?id=50510107 |