Eolian Origin of Quartz in Soils of Hawaiian Islands and in Pacific Pelagic Sediments

The particle-size distribution and oxygen-isotopic composition of quartz isolated from Hawaiian soils, east-central Pacific sediments, and tropospheric dusts are remarkably uniform. A common origin and tropospheric transport from continental land masses is suggested.

Surface Features of Metallic Spherules

Metallic spherules of variable character have been recovered from Antarctic snow. Three types were recognized from their surface features: type 1, smooth, polished spherules, apparently produced by surface melting of the particles upon entry into the earth's atmosphere; type 11, spherules with a corrugated surface caused by differential hardness of internal, intersecting lamellae, but modified by superimposed pits; and type III, spherules with random, circular depressions or pits apparently resulting from impact with submicroscopic particles. Spherules of types II and III were too small to have suffered abrasion by impacts in the earth's atmosphere, and it is postulated that their surfaces may have been produced by erosion in space. Preservation of these surface details would have been possible if entry into the atmosphere took place at low velocities and low-angle trajectories.

Hydrogen-Aluminum Clays: A Third Buffer Range Appearing in Potentiometric Titration

Wyoming montmorillonite (bentonite, particles 2 to 0.2 micro in diameter) treated with hydrogen-ionsaturated resin shows, on titration in 1N KNO(3) with NaOH by a continuously recording instrument, a third buffer range between pH 5.5 and 7.6 in addition to the first range where exchangeable hydronium is neutralized and the second range where a reaction with exchangeable aluminohexahydronium, Al(OH(2))(6)(3+), occurs. The third range increases considerably when the hydrogen-ion-saturated clay is aged, and is attributed to basic aluminum compounds formed in the presence of negative charges of montmorillonite, comparable to "third range" buffering noted in aged, partially neutralized aluminum chloride solutions.

Specific Surface Determination of Expansible Layer Silicates

The vacuum-oven technique for quantitative sorption of a glycerol duointerlayer by montmorillonite at 35 degrees C is adapted to 130 degrees C to obtain a mono-inter-layer of glycerol, glycerol vapor relative pressure being controlled by temperature differential. Values obtained for montmorillonite agree closely with theoretical values based on liquid glycerol density, while vermiculite retains a mono-interlayer of somewhat less than liquid glycerol density.

Dissolution of Interlayers from Intergradient Soil Clays after Preheating at 400 C

Dehydroxylated interlayers have been removed from chlorite-vermiculite-montmorillonite intergrades by boiling the preheated sample in 0.5N NaOH for 2.5 minutes. Elements extracted can be conveniently analyzed spectrophotometrically. A convenient method of estimating the amount of elements present in interlayer positions and preparing the sample for analysis for expanding and nonexpanding mineral components is thus provided.