Analytical studies will be made of the relationship between finestructure and microstructure, using data obtained from the Caribbean Sheets and Layers Transects Experiment (C- Salt) and from the Patch Experiment (PATCHEX). Optical observations in C-SALT revealed horizontal, rather than the expected vertical bands in regions favorable to salt fingers. Two analytical approaches will be used to investogate this phenomenon: fingers stretched and tilted by shear, and secondary instabilities due to horizontal intrusions. The larger scale CTD data set will be used to investigate the relationship between layer thickness and other staircase properties with the objective of better quantifying the vertical salt flux and larger scale properties. PATCHEX data will be used to investigate various aspects of shear instability and mixing, specifically the relationship between internal waves and the shear and strain fields.