resumo
Several cross-sections carried out in the Bit M'Cherga area (northern Tunisia) provided a complete Triassic-Miocene stratigraphic sequence, rather representative of the whole Tunisian Ridge Field located in the northern Atlas. Mineralogical analysis revealed a predominance of illite in the Early Cretaceous, while smectite is dominant in the Late Cretaceous and Tertiary. In terms of Atterberg limits, the Bit M'Cherga samples can be divided into two groups: one of moderately plastic clay samples until the Early Cretaceous, and another represented by the Late Cretaceous and Tertiary clays, which are the most plastic. As expected, the Atterberg limits increase with the amount of phyllosilicates present in the sample, which is dependent on the amount of smectite. This analysis was complemented by the use of the equivalent basal spacing (EBS) parameter, which gives a good correlation between the mineralogical characteristics of the clays and their plasticity. Using EBS, we can predict the mechanical/plastic behaviour of any clay sample according to its mineralogical composition. (C) 2009 Elsevier Ltd. All rights reserved.
palavras-chave
SEPIOLITE-PALYGORSKITE DEPOSITS; LIQUID LIMIT; SURFACE-AREA; SOILS
categoria
Geology
autores
Hajjaji, W; Hachani, M; Moussi, B; Jeridi, K; Medhioub, M; Lopez-Galindo, A; Rocha, F; Labrincha, JA; Jamoussi, F
nossos autores
João António Labrincha Batista
Professor Associado com Agregação
Walid Hajjaji
Bolseiro de pós-Doutoramentoagradecimentos
This research received financial support from the Ministry of Higher Education, Scientific Research and Technology (Tunisia) according to contract-programs and with foreign research and development institutes in the field of materials science (Agencia Espanola de Cooperacion Internacional, Group RNM-0179 of the Junta de Andalucia). We wish to express our gratitude to Prof. Ian MacCandless (Department of English and German Philology, University of Granada) for assisting us with the English version of the text.