Search

Lamellar features in naturally deformed hornblende are identical to (-1,01) mechanical twinning produced experimentally. Although plastic deformation features in amphiboles from tectonities are probably rare, where present, twinning may be a useful indicator of principal stress directions. (Author)

To provide a method for evaluating the future impact of ground traffic flow proposals for the Wright-Patterson Air Force Base, a computer program was described and constructed which simulates the normal vehicle movement situation for a 'typical' six A. M. to six P. M. Area B duty day. The model uses traffic data collected in an origin and destination study performed in 1970 as input to the computer program. The base is depicted through a complex array of one and two-way streets with accompanying intersections.

Photographic and infrared scanning surveys were made over Harper Lake, California, on three occasions during 1970 to evaluate the usefulness and limitations of aerial techniques for assessing ground conditions on dry lakebeds. The surficial geology of the lakebed was mapped and ground measurements were made for soil moisture, salt content, strength, and radiometric temperature. Infrared imagery in the wavelength region of from 1 to 5 micrometers is well-suited for detecting and mapping zones of soft or moist soils on playa surfaces, although spatial resolution is a limiting factor. The effects of surface soil conditions and micromorphological features on aircraft operations were also evaluated. (Author)

Amphibolite and hornblende were deformed in shear type apparatus, with over 200 tests run at conditions to 80 kb and 900C. Intragranular deformation was observed as undulatory extinction, deformation twins and kink bands. Kink band geometry tentatively establishes the slip system as T = (100), t = c. Shear strength at low temperatures, high pressures, and fast strain rates (27C, 40-50 kb, 0.10/sec), ranges between 11.6 and 12.8 kb for both hornblende and amphibolite. At 900C, shear strength decreases to less than 5 kb. Only thermally activated weakening manifests in shear tests. (Author)