Publications

A smooth field over the central Pacific for a million years indicates a nonuniform lower mantle of the earth.

New data show that the Olduvai normal geomagnetic polarity event is represented in Olduvai Gorge, Tanzania, by rocks covering a time span of roughly from 0.1 to 0.2 my and is no older than 2.0 my. Hence the long normal polarity event of this age that is seen in deep-sea sediment cores and in magnetic profiles over oceanic ridges should be called the Olduvai event. The lava from which the

The Chilean earthquake sequence of May 21–22, 1960, was accompanied by linear zones of tectonic warping, including both uplift and subsidence relative to sea level. The region involved is more than 200 km wide and about 1000 km long, and lies along the continental margin between latitude 37° and 48° S. Significant horizontal strains accompanied the vertical movements in parts of the...

An ultrasonic method for determining velocity has been developed that is independent of phase‐change errors due to reflection of specimen waves from coupling films. The method also eliminates the possibility of error due to conditions of nonhydrostatic stress at a specimen‐transducer or specimen‐delay line interface. Preliminary data are given for Alcoa 2024‐T4 aluminum and are compared...

A network of 64 seismic-refraction profiles recorded by the U.S. Geological Survey in California and Nevada and adjacent areas of Idaho, Wyoming, Utah, and Arizona from 1961 to 1963 was re-interpreted. From record sections compiled for all profiles, a basic travel-time diagram can be derived. In addition to the first arrivals on profiles in the Snake River Plain, the northern Basin and...

Eleven samples of fluids which had been squeezed on board ship, and four, packaged sediment samples were received in our laboratories. As in Leg 2, the volumes of fluid available were scanty and did not permit multiple determinations of constituents in many of the samples; in Hole 21 the fluid available sufficed only for refractometer readings (a few tenths of a milliliter). Therefore...

Measurements of ground motion generated by nuclear explosions in Nevada were made for 37 locations near San Francisco Bay, California. The results were compared with the San Francisco 1906 earthquake intensities and the strong-motion recordings of the San Francisco earthquake of March 22, 1957. The recordings show marked amplitude variations which are related consistently to the geologic...

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In two separate events, Revelstoke and Allende, the air through which a fireball had been observed to pass was sampled for meteoritic debris. Particulate matter was collected on fibrous filters, which were mounted on aircraft and flown downwind from the site of the meteorite fall at altitudes of 10,000–12,000 m. From Revelstoke, a highly distinctive assemblage of particles was collected...

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