Drilling and geophysical logging of Deccan basalt during groundwater exploration in Central India demonstrated that the Deccan lavas comprise a series of simple lava flows, 15–20 m thick, having a porous upper cooling surface with thin clay development and a layered structure. Geophysical logging has proved capable of resolving the layering and produced consistent log responses. Gamma-ray logs were especially useful to identify the weathered flow surfaces but further revealed certain lavas have distinctly higher radioactivity. The higher radioactivity flows were found to be of regional significance. The resolution of the layering and positive identification of flows by geophysical logging permitted individual lavas to be recognized and traced over distances of at least 100 km with no apparent displacement. The logs provided a framework for a detailed stratigraphic sub-division of the lava sequence, and also a key to investigate lateral and vertical variation in aquifer properties.

This essay presents a dissenting view of prevailing concepts of education and approaches to educational reform. Reforms currently directed at American schools are grounded in conceptual and institutional frameworks that fail to confront the most fundamental problems of our age. The authors outline the nature of these problems,suggest ways in which education in America both reflects and exacerbates the problems, and finally sketch an educational model they feel is more appropriate to the challenges of modern America.

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For many years, wireline tracer surveys have been used to determine the height of fractures created during hydraulic stimulation procedures. A recent advancement in fracture evaluation technology has been to tag different stages of a fracture operation with multiple radioactive tracers, providing the capability to discern between created and propped fracture heights in one or more zones of interest. In this research, a wireline instrumentation and data analysis system is implemented to identify and separate the individual yields from multiple radioactive tracers, with an additional feature that determines whether the tracer material is inside of the borehole or distributed throughout the created fracture zone. A single postfracture pass of the logging instrument is used to accumulate gamma ray spectra at each 7.6 cm interval along a borehole. A weighted least‐squares spectrum unfolding algorithm calculates the radioactive intensities as a function of depth, while the peak‐to‐Compton down‐scatter ratio determines the proximity of the tracer material to the wellbore. Field examples illustrate the effectiveness of the system for the evaluation of multistage fracture operations.

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