摘要:

In the eighteenth century, as the Industrial Revolution gathered momentum, a new kind of researcher somewhere between scientist and technologist was appearing—the engineer. “Engineer” may be too elegant a word to describe some of these people. Most did not have degrees and belonged to no professional organizations. Yet they took on wide responsibilities. They were not members of guilds, for they stood above that level, and they were not financiers, though they did often invest their own money and searched for funds from the wealthy. In this article I deal with the mining industry, where, as nowhere else, there was a need for technical expertise and a necessity for organization on a relatively large

ISSN:0002-8606    

DOI:10.1029/89EO00363

年代:1989

数据来源: WILEY

摘要:

Paleomagnetic and rock magnetic research in Australia has for some time been among the best in the world, mainly through the work of groups at the Australian National University (ANU), the Bureau of Mineral Resources (BMR) and the Commonwealth Scientific and Industrial Research Organization (CSIRO). Environmental magnetism is a relatively new field, but one that is developing rapidly in Australia, as elsewhere. This report outlines both past and present research and suggests some future directions.Environmental magnetism in the Australian region began as an adjunct to paleomagnetic studies of lake sediments in the Highlands of Papua New Guinea (PNG) [Thompson and Oldfield, 1978; Oldfield et al, 1980] and in Western Victoria [Barton and Polach, 1980]. In both cases, magnetic susceptibility and some remanence measurements were used for core correlation.

ISSN:0002-8606    

DOI:10.1029/89EO00366

年代:1989

数据来源: WILEY

摘要:

The Third Annual Northeast Paleomagnetic Workshop was held September 23 at the University of Massachusetts, Amherst; Laurie Brown of the university's geology department was the organizer. On September 22, Sue Halgedahl of Lamont Doherty Geological Observatory, Palisades, N.Y., gave a lecture on magnetic domain structure and its relationship to paleomagnetic stability.

ISSN:0002-8606    

DOI:10.1029/EO070i048p01513-01

年代:1989

数据来源: WILEY

摘要:

The tectonic expulsion of fluids theory could explain the presence of lead‐zinc ores in sedimentary rocks. Originally proposed in 1986 by Jack Oliver, Cornell University, Ithaca, N.Y., the theory is based on the subduction of tectonic plates, where hot mineral‐bearing fluids would be expelled from the subduction zone to circulate in overlying sediments during a continent‐continent collision.The problem with Oliver's idea is that formation ages of some lead‐zinc deposits are older than the formation ages of mountains close to the deposits. According to the theory, the age of the mountains would equal the age of mineral

ISSN:0002-8606    

DOI:10.1029/89EO00372

年代:1989

数据来源: WILEY

摘要:

Ever since the recognition of plate tectonics as a major Earth process, maps of the orientation of stress in Earth's crust have given us one of the most direct clues to the forces that drive plate movements. We now know from these maps that stress orientations are consistent on a regional scale, that the boundaries between provinces of uniform stress direction generally coincide with major physiographic and structural boundaries, and that for many regions the orientation of the maximum compressive horizontal stress generally coincides with directions of plate motion [e.g., Zoback and Zoback, 1989].On a regional scale, maps of crustal stress have provided striking evidence of the low strength of plate margin at the San Andreas Fault in California [M. D. Zoback et al, 1988]. In industry, maps of stress orientations have been used to plan secondary recovery projects for oil and gas [Bell and Babcock, 1986]and evaluate seismic risk near critical facilities [e.g., Stock et al., 1985].

ISSN:0002-8606    

DOI:10.1029/89EO00375

年代:1989

数据来源: WILEY