Origin and Mineralogy of Sepiolite and Palygorskite From the Tuluanshan Formation, Eastern Taiwan

Abstract

The Tuluanshan Formation of the eastern Coastal Range of Taiwan overlies an andesitic core complex presumed to be the source of hydrothermal fluids responsible for the Si- and Mg-rich mineralization of sepiolite and palygorskite (attapulgite) which are found in veins within fissures and in fracture zones of the volcanic rocks of the region. This study was undertaken in order to understand these relationships better by characterizing sepiolite and palygorskite in this Formation and by examining their occurrence and distribution in the Tungho (TH) and Chunjih (CJ) areas. Samples were analyzed using X-ray diffraction (XRD), thermal analysis, Fourier-transform infrared (FTIR) spectroscopy, and petrographic, scanning (SEM), and transmission (TEM) electron microscopic methods. Sepiolite and palygorskite are blocky and earthy-type materials that display fibrous characteristics when viewed using TEM and SEM and occurred alone or with chalcedony in veins. The fibers of blocky sepiolite are commonly intercalated with smectite but the earthy type of sepiolite and palygorskite observed in this study displayed precipitation from fluid enriched in Si, Al, Mg, and minor Fe and depleted in other ions at an earlier stage of offset of the andesitic veins. Continuation of reverse faulting and high shearing stress caused the precipitation of a significant quantity of interlaminated sepiolite. Sepiolite and palygorskite were formed at an earlier stage of fluid interaction relative to smectite in the Tuluanshan Formation.

Thermal and rheological effects of sepiolite in linear low‐density polyethylene/starch blend

“…Spectrum (i) shows the characteristic absorption bands at 2840 and 2930 cm À1 , which correspond to CH 2 stretching modes of vibration of polyethylene. 23 The important adsorption bands of starch and sepiolite were also found in both non-crosslinked (LS4/30) and crosslinked formulations (XLS4/30) as shown in Figure 1(B) (v, vi) It was observed that the siloxane SiAOASi and SiAOAC bands was not clearly differentiated in XLS4/30 because sepiolite bands overlap these bands in this region. 21,22 Additionally, band corresponding to SiAOASi symmetric vibrations were also observed at 800 cm À1 .…”

A microscopic approach to the pedogenic formation of palygorskite associated with Quaternary calcretes of the Adana area, southern Turkey

“…Palygorskite [Si 8 Mg 2 Al 2 O 20 (OH) 2 (OH 2 ) 4 .4H 2 O] is a common phyllosilicate known from marine and continental sediments, soils, and hydrothermally affected rocks (Singer, 1989;Suárez et al, 1994;Wang et al, 2009). Its occurrence is also reported from calcretes as a minor component (Wright and Tucker, 1991;Verrecchia and Le Coustumer, 1996;Eren et al, 2008;Kaplan et al, 2013).…”

Hybrid pigments from fibrous clays and chromophores inspired by the color of fruits, flowers and wine

“…The sepiolite (SEP) used in this work was SepSp-1 reference clay from the Clay Minerals Society Source Clay Minerals Repository; this material was manually ground to a powder that passed freely through a 40 mesh wire sieve but otherwise used with no additional purification. The chemical composition, characterization and properties of this clay have been described (Gionis et al, 2007;He et al, 1996;Madejová et al, 2017;Vogt et al, 2002;Wang et al, 2009;Weir et al, 2002).…”