Geochemistry of Radiolarites from the Betic Cordillera: Implications for Source Determination of Raw Material in Archaeology
In the Betic Cordillera (Subbetic Zone) radiolarian bearing sequences of the Middle to Late Jurassic age have been studied from a petrological and geochemical point of view. The objective of this paper is stablish the differentiating characteristics among the six chosen sections (AB, AG, SP, JH, SE...
| Autores: | , |
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| Tipo de recurso: | otro |
| Fecha de publicación: | 1997 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/160718 |
| Acceso en línea: | http://hdl.handle.net/10261/160718 |
| Access Level: | acceso abierto |
| Palabra clave: | Radiolarite Archaeology Geochemistry Source provenence |
| Sumario: | In the Betic Cordillera (Subbetic Zone) radiolarian bearing sequences of the Middle to Late Jurassic age have been studied from a petrological and geochemical point of view. The objective of this paper is stablish the differentiating characteristics among the six chosen sections (AB, AG, SP, JH, SE and ZG) to use them as criteria for determination sources of the archaeological artefacts found in this area. The radiolarite beds are largely composed of quartz (50%-80%), with lesser amounts of calcite (≤ 30%), clay minerals (smectite, illite, and occasionally kaolinite) (10% to 35%) and hematites (≤ 5%). Analysis of major, minor, traces and rare earth elements is the best method to separate radiolarites among the studied sections. According to this, biogenic and total silica let us define two groups of sections: (a) AS and AG, and (b) ZG, SP and JH, and the SE section is not clearly defined. In the first group, AG and AS sections differentiate themselves when the percentage of biogenic silica (greater than 64%) is compared to the percentage of CaO. The AG samples adapt themselves to a typical regression line, and the AS samples are distant from the regression line. Furthermore the samples of the AB section clearly characterize themselves by Ce/Ce* and Lun / Lan indexes. In relation to the second group (≤ 61% of biogenic silica), the samples from the SP and JH sections are defined by a typical regression line when the percentage of biogenic silica is compared to the percentage of AI2 O3 or K20. |
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