Radiogenic Argon Released by Stepwise Heating of Glauconite and Illite: The Influence of Composition and Particle Size

A. A. Hassanipak and J. M. Wampler 717

Partitioning of Binary Solvents on Charged Expandable Clays

Joseph R. Feldkamp and Thomas B. Stauffer 727

Morphology of Lead(II) and Chromium(III) Reaction Products on Phyllosilicate Surfaces as Determined by Atomic Force Microscopy

Huamin Gan, George W. Bailey and Y. Shane Yu 734

Crystal Structure Modeling of a Highly Disordered Potassium Birnessite

Kerry L. Holland and Jeffrey R. Walker 744

Swelling Pressure of Montmorillonite Layers versus H-O-H Bending Frequency of the Interlayer Water

Laibin Yan, Philip F. Low and Charles B. Roth 749

Adsorption of Nitrilotriacetate (NTA), Co and CoNTA by Gibbsite

D. C. Girvin, P. L. Gassman and H. Bolton, Jr. 757

Polymerization of Benzene and Aniline on Cu(II)-Exchanged Hectorite Clay Films: A Scanning Force Microscope Study

Michael P. Eastman, Michael E. Hagerman, Jennifer L. Attuso, Edlin D. Bain and Timothy L. Porter 769

Preparation, Structural Characteristics and Catalytic Properties of Large-Pore Rare Earth Element (Ce,La)/Al-Pillared Smectites

Ernst Booij, J. Theo Kloprogge and J. A. Rob Van Veen 774

Effect of Heating on Swelling and Dispersion of Different Cationic Forms of a Smectite

M. Chorom and P. Rengasamy 783

Characterization of Soil Clay Minerals: Decomposition of X-Ray Diffraction Diagrams and High Resolution Electron Microscopy

Dominique Righi and Françoise Elsass 791

Submicroscopic Structure of Fe-Coatings on Quartz Grains in Tropical Environments

E. Padmanabhan and A. R. Mermut 801

X-Ray Diffraction Analysis of Thin Clay Films from Dilute Suspensions Using Glancing Incidence Diffraction

Katherine Ozalas and Benjamin F. Hajek 811

Inter-Basinal Comparison of the Diagenetic Evolution of Illite/Smectite Minerals in Buried Shales on the Basis of K-Ar Systematics

Norbert Clauer and Sam Chaudhuri 818

Experimental Transformation of Kaolinite to Halloysite

Balbir Singh and Ian D. R. Mackinnon 825

Illite Polytype Quantification Using WILDFIRE© Calculated X-Ray Diffraction Patterns

Georg H. Grathoff and D. M. Moore 835

Alunite, Natroalunite and Hydrated Halloysite in Carlsbad Cavern and Lechuguilla Cave, New Mexico

Victor J. Polyak and Necip Güven 843

Corrections 851