Clay minerals origin

W. D. KeUer, "Processes of Origin of the Clay Minerals," Proceedings of the Soil Clay Mineral Institute, Virginia Polytechnic Institute, Blacksburg, Va., 1962. 

Shimoda, S., Kohyama, N. and Ichikawa, Y. (1974) Some problem on the origin of interstratified mica clay minerals. J. Mineral. Soc. Japan, 11, 169-179. 

Many gums and resins that ooze out of the trees also behave like plastic. Sealing Wax when warmed becomes plastic can be impressed with a seal. Glass and clay are also plastic material of mineral origin. By early nineteenth century, man had learned to mould many articles from natural gums and resins and make protective films of varnish from Shellac. 

Cairns-Smith, A. G. Hartman, H. Clay Minerals and the Origin of Life Cambridge University Press Cambridge, 1986. 

The clay minerals of aeolian origin comprise 25 to 75% of the mass of pelagic sediments. The large range in composition reflects the latitudinal nature of the dust belt as well as dilution by other locally important particle types such as clay minerals of volcanogenic origin and biogenic hard parts (calcite and opaline silica). 

The abyssal clays are composed primarily of clay-sized clay minerals, quartz, and feldspar transported to the siuface ocean by aeolian transport. Since the winds that pick up these terrigenous particles travel in latitudinal bands (i.e., the Trades, Westerlies, and Polar Easterlies), the clays can be transported out over the ocean. When the winds weaken, the particles fell to the sea siufece and eventually settle to the seafloor. Since the particles are small, they can take thousands of years to reach the seafloor. A minor fraction of the abyssal clays are of riverine origin, carried seaward by geostrophic currents. Despite slow sedimentation rates (millimeters per thousand years), clay minerals, feldspar, and quartz are the dominant particles composing the surface sediments of the abyssal plains that lie below the CCD. Since a sediment must contain at least 70% by mass lithogenous particles to be classified as an abyssal clay, lithogenous particles can still be the major particle type in a biogenous ooze. 

Montmorillonite An iron-rich clay mineral that has a very high cation exchange capacity. Unlike the other clay minerals, a significant amount of sedimentary montmorillonite is hydrothermal in origin. 

Effect of RAMEB on Water Vapor Adsorption on Soils. Experimental adsorption isotherms for the RAMEB-treated soils are presented in Figure 1 [see p. 127]. As pure RAMEB sorbs a very high amount of water (ca. 1 g g" at p/po = 0.99), an increase in water sorption was expected after RAMEB addition to all soils. However, the isotherms for RAMEB-treated clay-rich S6 and S7 soils showed lower adsorption than the original soils, which is illustrated for S7 soil with 49% clay. This potentially indicates that RAMEB decreases the amount of water-available surfaces in clay-rich soils, similar to what was observed for pure clay minerals (20). In sandy soils (S1-S4), the water sorption markedly increased, particularly at higher RAMEB doses, as is illustrated for S2 soil. 

Mullite is almost twice as abundant in low-Ca fly ash when compared to high-Ca fly ash, mainly due to differences in the Al content of the clay minerals associated with the coal (McCarthy et al. 1990). Using atomic absorption spectroscopy (AAS) and scanning electron microscopy /electron microprobe analyses (SEM/ EMPA) Stevenson Huber (1987) found a correlation between the elemental composition of ash particles and the clay mineral species in the raw coal. They concluded that the geologic origin of the coal had a significant impact on the microchemical composition of the ash. 

It is often observed in tiny crystals of micrometer order, such as clay minerals, that the entire surface of a crystal face is covered by elementary spiral layers originating from one screw dislocation (Fig. 5.3). Figure 5.10(a) shows such an exceptional case observed on a (0001) face of a SiC crystal synthesized by the Acheson method. However, such a situation is almost exceptional on crystal faces larger than millimeter size, and is encountered only on crystals synthesized under very precisely controlled conditions. In general, there are many growth centers on one crystal face, and steps from these centers bunch together to form macro-steps, which constitute the step patterns of the face. 

---