Late Lower Cambrian trilobite correlation between Spain and Jordan  

DIEs M. E., GOZALO R. AND LIÑAN, E.

The Bilbilian is a chronostratigraphic unit for the late Lower Cambrian of the Mediterranean region. It is represented mainly by siliciclastic ormixed facies where trilobites are not abundant. New Bilbilian trilobitefindings in the North of Spain have permitted us to compare the Bilbilian sequences from Spain with  those fromJordan.

Two trilobites assemblages may be distinguisedin the Spanish Bilbilian strata: the lower assemblage is composed of thetrilobite taxa Kingaspis (Kingaspidoides) c£ velatus Sdzuy,1961 and Realaspis strenoides Sdzuy, 1961 which are present in the sequences of Montes de Toledo (central Spain) and Cadenas Ibéricas (NE Spain). Theupper assemblage is composed of Kingaspis (Kingaspis) campbelli (King, 1923), Onaraspis altus (Liñán & Gozalo, 1986), Hamatolenus (Hamatolenus) ibericus Sdzuy, 1958 Protolenus (Hupeolenus) jilocanus (Liñán and Gozalo, 1986), Tonkinellasequei Liñán and Gozalo, 1999 and Sdzuyia sanmamesi Liñán and Gozalo, 1999.The first trilobite assemblage is considered as being of the Upper Marianian­Lower Bilbilian age (Sdzuy 1971) and the second trilobiteassemblage is considered as being of the Upper Bilbilian age. The Darocaregression took place between both assemblages.

In the late Lower Cambrian sequences of Jordan,two other trilobite assemblages have been considered by Rushton and Powell(1998). The lower assemblage contains Realaspis sp. nov. and Redlichops blanckenhorni Richter and Richter, 1941 while the upper assemblage contains K (K) campbelli and Palaeolenus antiquus (Chernysheva, 1956). Bothassemblages have also been assigned to the Bilbilian age by these authors.

The comparison between the late Lower Cambrian sequences and trilobitesfrom Spain and Jordan allow us to conclude that the assemblages with Realaspis may be considered as Lower Bilbilian and the assemblages withKingaspis (K) campbelli may be considered as Upper Bibilian. This new data improve thelate Lower Cambrian correlation between the Eastern and Western areas of the Mediterranean subprovince.  

Acknowledgements. We acknowledge support from the Dirección General de Enseñanza Superior, project PB96-0744. Ma Eugenia Dies receives a predoctoral research grant from the Departamento de Educación y Cultura of the Diputación General de Aragón.  

References  

Sdzuy, K.1971. Acerca de la correlación del Cambrico inferior en la Península Ibérica.  I CongresoHirpano­LusoAmericano de Geología Económica. Geología II., 753-768.

Rushton, A.WA. and Powell. J.H. 1998.  A Review of thestratigraphy and trilobite faunas from the Cambrian Burj Formation in Jordan. Bull nat. Hist. Mus. Lond.(Geol.), 54 (2), 131-146