000086187 001 __ 86187
000086187 024 8_ $9 driver $9 artpubuab $a oai:ddd.uab.cat:86187
000086187 035 __ $9 articleid $a 16965728v1n1p73
000086187 035 __ $9 doi $a 10.1344/105.000001593
000086187 041 __ $a eng
000086187 100 __ $a Beresi, M.S.
000086187 245 1_ $a Cambrian sponge spicules and Chancelloriid sclerites from the Argentine Precordillera : a Review
000086187 520 3_ $a Spicules of sponges and sclerites of chancelloriids have been collected from in situ Cambrian sections of the La Laja Formation (San Juan Precordillera). They have also been collected from carbonate olistoliths, which were 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 were deposited 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 slope environments which developed in the western Precordillera. Cambrian Porifera and sponge-like chancelloriid assemblages are known mainly from fragments of skeletal nets, dissociated spicules and sclerites, which enable us to define two assemblages. The first assemblage of spicules was defined from the upper Lower to Middle Cambrian sequences of the La Laja Formation. This assemblage consists of a variety of stauractines and sclerites of Chancelloria WALCOTT. The family Protospongiidae is represented by triradiate prodianes, pentactines and hexactines, 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 Sombreros and 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. Anthaspidellid sponges 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 Cambrian platform and slope facies of the Precordillera contribute additional data for a better understanding of the relationships between the eastern and the western facies assemblages, which developed in the Precordillera during the Cambrian. Therefore, they are useful for paleoenvironmental and paleogeographical interpretations of the Cambrian depositional framework.
000086187 540 __ $a Tots els drets reservats $u http://www.europeana.eu/rights/rr-f/
000086187 594 __ $a Article de fons
000086187 653 1_ $a Sponge spicules
000086187 653 1_ $a Chancelloriids
000086187 653 1_ $a Cambrian
000086187 653 1_ $a Precordillera
000086187 653 1_ $a San Juan
000086187 653 1_ $a Mendoza
000086187 653 1_ $a Argentina
000086187 655 _4 $a info:eu-repo/semantics/article
000086187 655 _4 $a info:eu-repo/semantics/publishedVersion
000086187 710 1_ $a IANIGLA, CRICYT
000086187 773 __ $g Vol. 1, Núm. 1 (2003), p. 73-84 $t Geologica acta $x 1696-5728
000086187 856 40 $p 12 $s 3368399 $u http://ddd.uab.cat/pub/geoact/geoact_a2003v1n1/geoact_a2003v1n1p73.pdf
000086187 973 __ $f 0073 $l 84 $m  $n 1 $v 1 $x geoact_a2003v1n1 $y 2003
000086187 980 __ $a ARTPUB $b UAB $b GEOACT