ransmission electron microscopy of clay minerals in North Pacific deep-sea sediments has revealed the existence of intermediate states between montmorillonite, talc and palygorskite. During the earliest diagenetic stages of montmorillonite, short needles grow from the rim of montmorillonite films, and sometimes from rims of talc. The short needles, 0.1μE in length, are incorporated into the palygorskite. The electron diffraction patterns of the primitive palygorskite show well defined spots at 4.49, 2.61, 2.26 and 1.70Åsuggesting high crystallinity. The short needles precede formation of elongated fibres with sharp edges which eventually form lamellae aggregates and fibre bundles. EDX analysis shows that the major element concentrations of bundled palygorskite are Mg, Al, Fe and Si (1:1.2:1:5.1). XRD, DTA and SIMS data support these TEM results. The formation of magnesium-rich clay minerals during diagenetic processes in deep-sea sediments could be a significant sink in the marine magnesium cycle.

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Two types of landslide, namely bedrock and colluvial-soil slides, are found in the northern part (Kitamatsuura-gun) of Nagasaki Prefecture. The bedrock slide has a slip surface in the tuffaceous coal seams intercalated in the Miocene sediments composed of sandstone and mudstone. The colluvial-soil slide occurred in colluvial materials overlying bedrock and movement was for a relatively short distance. The samples were collected from sites undergoing bedrock or colluvial-soil slide and analyzed for physical, chemical and mineralogical properties. A large clay mineralogical difference was found between the samples of bedrock and colluvial-soil slides, while such properties as particle-size distribution and proportions of exchangeable cations were not substantially different. The sample from the site undergoing a bedrock slide was characterized by a high amount of smectite, and the samples from colluvial-soil slides contained mica, kaolinite, and less smectite. Such clay mineralogical difference may partly be related to the small scale of colluvial-soil slides compared to bedrock slides.

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Suspensions of sodium kaolinite flocs were sheared in a rotary-type, programmableviscometer. A sudden, irreversible, loss of shear stress, as recorded by a torsion spring attached to a bell-shaped rotor, indicated that a sensitivity to shearing forces occurred at low rates of shear (-25 s^-1). This sensitivity was at a maximumfor a 10% w/w concentration at pH 5.5 and could be reduced by: change of pH or concentration, treatment with ultrasonic vibration, successive cycles of shearing or addition of sodium chloride.
Scanning electron micrographs of flocs revealed a clustering of particles comprised of fine-sized kaolinite plates aggregated face to face. The combination of permanent charge on plate faces and pH dependent charge on edges of the aggregate led to the establishment of a network of clusters that entrained water. This clustering of particles was sensitive to weak shearing forces, much stronger forces would have been required to separate kaolinite plates that were aggregated face to face.

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The physical, chemical, mineralogical and firing characteristics of the grey clayshale of the Imo Formation and the overlying reddish-brown sandy and silty clay of the Ososun Formation were studied. X-ray analysis shows that montmorillonite is the dominant clay mineral in the clay-shale while kaolinite is dominant in the reddish-brown clay. The pH determinations indicate a marine environment of deposition for the clay-shale and a continental origin for the reddish-brown clay .
Various tests for economic evaluations indicate that the clay-shale can be used as components of drilling fluid and as a source of catalyst in the petrochemical industry, while the reddish-brown clay can be used in the manufacture of bricks, fl oor tiles and pottery.

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