Universidad Complutense de Madrid
E-Prints Complutense

Spanish palygorskites: geological setting, mineralogical, textural and crystal-chemical characterization

Impacto

Downloads

Downloads per month over past year

Suárez, Mercedes and García Rivas, Javier and Sánchez Migallón, Juan Morales and García Romero, Emilia (2018) Spanish palygorskites: geological setting, mineralogical, textural and crystal-chemical characterization. European Journal of Mineralogy, 30 . pp. 733-746. ISSN 0935-1221, ESSN: 1617-4011

[img]
Preview
PDF
Creative Commons Attribution Non-commercial.

11MB

Official URL: https://www.schweizerbart.de/papers/ejm/detail/30/89831/Spanish_palygorskites_geological_setting_mineralogical_textural_and_crystal_chemical_characterization



Abstract

A representative group of palygorskites from the six most important Spanish deposits and six other occurrences were studied comparing their mineralogy, textural features, crystal-chemistry, and surface properties. These palygorskites have different geological origin: (1) sedimentary in large Tertiary continental basins, (2) hydrothermally altered volcanic rocks in the southern Spanish Peninsula, also Tertiary in age; and (3) fault-hosted pure palygorskites. The most common impurities are quartz and carbonates, both calcite and dolomite, but also feldspar, illite, smectite, and sepiolite have been identified. The structural formulae obtained show great variability between samples, as well as with respect to the theoretical formula for palygorskite, as they range from magnesian to aluminous palygorskites. The most common fibre length ranges between 1 and 10 µm but the palygorskites of hydrothermal origin are much longer, with lengths over 10 µm. The shorter fibres give rise to tightened textures, while longer fibres usually generate more open textures. These properties, along with the degree of compaction, condition the porosity of the sample, which in turn influences its surface properties. The specific surface areas obtained range between 30 m2 g−1 and 263 m2 g−1, depending on the impurities content and on the texture and crystal-chemistry; the highest values correspond to Mg-rich palygorskite.


Item Type:Article
Uncontrolled Keywords:palygorskite, hydrothermal palygorskite, clay minerals, Tertiary Spanish basins, mineral assemblage, structural formula, texture, surface properties, SEM, adsorption of N2
Subjects:Sciences > Geology > Mineralogy
ID Code:50954
Deposited On:30 Jan 2019 19:20
Last Modified:07 Feb 2019 09:42

Origin of downloads

Repository Staff Only: item control page