Scanning Electron Microscope Examination of Quartz Surface Textures from Kaolinized Granitic Rocks

Observation of surfaces of quartz in kaolinized granitic rocks by scanning electron microscopy was applied to provide information on the environmental conditions of kaolinization. Comparing with the quartz grain surfaces from kaolinite and halloysite specimens each other, quartz crystals from kaolinite specimens show extremely rough surfaces caused by deep dissolution pits, while the surfaces from halloysite are relatively smooth surfaces. Quartz surfaces in hydrothermal kaolinized granitic rocks are extremely rougher than those in weathered granitic rocks

Job sprawl, spatial mismatch, and black employment disadvantage

This paper examines the relationship between job sprawl and the spatial mismatch between blacks and jobs. Using data from a variety of sources, including the 1990 and 2000 U.S. Census and U.S. Department of Commerce's ZIP Code Business Patterns, I control extensively for metropolitan area characteristics and other factors. In addition, I use metropolitan area physical geography characteristics as instruments for job sprawl to address the problem of simultaneity bias. I find a significant and positive effect of job sprawl on mismatch conditions faced by blacks that remains evident in the twostage least squares models but not in first difference change regressions. The crosssectional effect is particularly important in the Midwest and West, and in metropolitan areas where blacks' share of the population is large and where blacks' population growth rate is relatively low. Among others, the results also reveal that the measures of mismatch and job sprawl used in this analysis are highly correlated with blacks' employment outcomes in the expected direction. © 2006 by the Association for Public Policy Analysis and Management