Fe³⁺-Rich Montmorillonite-Beidellite Series in Ayvacik Bentonite Deposit, Biga Peninsula, Northwest Turkey

Abstract

Abstract--The Ayvaclk bentonites, products of Miocene calc-alkaline volcanic rocks, are composed of smectite of the montmorillonite-beidellite series. Fault-related hydrotherrnal solutions have altered andesitic rocks to dioctahedral smectites. Differences in the micro-morphology of the two end-members are distinguished by scanning electron microscopy (SEM) studies. The beidellite particles are of delicate ribbons and rosette habits, whereas montmorillonite particles are very thin, curled sheets and flakes. Clay size (<2 txm) fractions contain (in wt. %) 54.90-56.80 Sit 2, 19.65-28.54 Al=Oj, 0.45-6.28 Fe203, 0.10-1.72 Cat, 0.80-4.15 MgO, 0.55-1.88 K2 O, and 0.08-1.15 Na20, which confirm that the beidellites are Fe-rich (5.06-6.28 wt. %), except for one sample (0.45 wt. % Fe2Oj). The Greene-Kelly test (Li-saturation and heating) gave very good results for the measurement of the d(001) of the two end-members. Nickel, Ti, and Cr enrichment in smectite is related to the chemical composition of hydrothermal solutions that passed through the ophiolite complex.

Study of interactions between rhodamine B and a beidellite-rich clay fraction

“…Elemental analysis of the Na-Bd clay (Table 1), in agreement with the XRD analysis, showed that the minor K 2 O content might be ascribed to illite (Bergaya et al, 1986;Çoban & Ece, 1999). In addition, the Fe and Mg contents are too small to account for nontronite (Fe-rich smectite) and saponite (Mg-rich smectite) (Suquet et al, 1987;Casal et al, 1997;Köster et al, 1999), which is in accord with the predominance of beidellite in the Na-Bd clay fraction.…”

“…The CEC of the Na-Bd clay was 71 meq 100 g -1 . This value is relatively low compared to beidellites of other origins (Goodman et al, 1976;Bergaya et al, 1986;Suquet et al, 1987;Çoban & Ece, 1999); this difference might be mainly due to the presence of illite and kaolinite in the fine fraction; those have low CEC values. Typical CEC values are 3-15 meq 100 g -1 for kaolinites and 10-40 meq 100 g -1 for illites (Caillère et al, 1982).…”

Origin of the Basoren (Kutahya, W Turkey) bentonite deposits

“…These data suggest that the second group of smectites are montmorillonites, while Cayırlık smectite has a significant beidellitic component. A comparison between Basoren montmorillonites and beidellites and other montmorillonites and beidellites (Lim & Jackson, 1986;Coban & Ece, 1999;Post et al, 1997) is shown in Table 2.…”

Bentonite electrical conductivity: a model based on series–parallel transport

“…Bentonite is a type of clay consisting predominantly of smectite minerals, usually montmorillonite and beidellite, described by Coban and Ece [1] and Sposito [2] and was first described by Knight [3] as a highly plastic and highly weathering resistance material. This particular type is highly swelling in the presence of moisture, and its large double-layer (DL) is convenient for the retention of cations, toxins, etc.…”