The Geologic Features of the Occurrence of Copper in North America

Copper is of such widespread natural occurrence in North America and there are so few metal-mining districts that have not contributed to its production that it is obviously necessary in any brief general treatment of the geology of the copper deposits of the continent to restrict the discussion to the districts in which copper is the dominant metallic product. Otherwise the summary would be unreasonably long. The copper deposits of North America may be classified in various ways--with respect to form, genesis, geologic age, distribution, and distinctive features of character or occurrence. On the whole, an areal grouping will probably be most satisfactory. To some extent this will coincide with a classification based on the form or character of the deposits, but there will be notable exceptions. Classification, after all, is merely a human-expedient for systematizing description and for facilitating studies of origin. It is essentially artificial and sets up class distinctions, the legality of which, at least so far as ore deposits are concerned, Nature does not recognize

Directions of progress in economic geology

The subject chosen for my address this morning is of rather general character and one that should permit a retiring president to exercise his privilege of indulging in retrospective as well as in prospective views and of expressing ideas which, although possessing little novelty, may, nevertheless, be worthy of consideration. My own work in economic geology has been mainly with ore deposits, and if in the present address that particular aspect of geology seems to receive disproportionate attention, this is due to the limitations of my own experience and not to any desire to minimize the significance of geology in relation to the occurrence of oil, coal and other non-metallic resources and to problems of engineering in connection with the construction of dams and reservoirs, the driving of tunnels, and other projects in which the character and structure of the rocks and the geologic history of the region may be of fundamental importance

The Geologic Features of the Occurrence of Copper in North America

Copper is of such widespread natural occurrence in North America and there are so few metal-mining districts that have not contributed to its production that it is obviously necessary in any brief general treatment of the geology of the copper deposits of the continent to restrict the discussion to the districts in which copper is the dominant metallic product. Otherwise the summary would be unreasonably long. The copper deposits of North America may be classified in various ways--with respect to form, genesis, geologic age, distribution, and distinctive features of character or occurrence. On the whole, an areal grouping will probably be most satisfactory. To some extent this will coincide with a classification based on the form or character of the deposits, but there will be notable exceptions. Classification, after all, is merely a human-expedient for systematizing description and for facilitating studies of origin. It is essentially artificial and sets up class distinctions, the legality of which, at least so far as ore deposits are concerned, Nature does not recognize

Thorough Geological Investigation is of Prime Importance When Selecting a Dam Site

To some readers of this brief article it may appear that unnecessary stress is laid upon considerations that are obvious. The failure of the St. Francis dam, however, is simply the latest of many disasters that have occurred because attention was not given to conditions that should have been clearly perceptible to those responsible for the project

Directions of progress in economic geology

The subject chosen for my address this morning is of rather general character and one that should permit a retiring president to exercise his privilege of indulging in retrospective as well as in prospective views and of expressing ideas which, although possessing little novelty, may, nevertheless, be worthy of consideration. My own work in economic geology has been mainly with ore deposits, and if in the present address that particular aspect of geology seems to receive disproportionate attention, this is due to the limitations of my own experience and not to any desire to minimize the significance of geology in relation to the occurrence of oil, coal and other non-metallic resources and to problems of engineering in connection with the construction of dams and reservoirs, the driving of tunnels, and other projects in which the character and structure of the rocks and the geologic history of the region may be of fundamental importance

Report of the Commission Appointed by Governor C. C. Young to Investigate the Causes Leading to the Failure of the St. Francis Dam Near Saugus, California

This report embodies the conclusions of the commission appointed to investigate the causes for the failure of the St. Francis Dam on March 12, 1928. California deplores the heavy loss of life and property that this disaster entailed. To prevent a recurrence of a like catastrophe, we believe it imperative that whatever lessons the failure of this dam may teach should be made public for the benefit of the people of our state. It was also our thought that the investigation into the causes of the failure of this dam should be made by an agency that was not in any way connected with the preparation of the plans, the construction, or the operation of the dam. Accordingly a commission of engineers and geologists of expert knowledge and eminent reputation was appointed to make this study. The instructions given its members appear in the body of their report. Despite the arduous service that the investigation required, the members of the commission served without personal compensation to them- selves, thus placing their report upon a high plane of unselfish public service. On behalf of the people of California, I extend to them the thanks of the state. As the future of California depends in a large measure upon the storage of water, and the construction of dams, it is gratifying to note that this report finds that such structures can be built with entire safety when due regard is paid to suitability of foundations and correctness of design. This is the great lesson of the disaster. C. C. Young, Governor of California

Report of the Commission Appointed by Governor C. C. Young to Investigate the Causes Leading to the Failure of the St. Francis Dam Near Saugus, California

This report embodies the conclusions of the commission appointed to investigate the causes for the failure of the St. Francis Dam on March 12, 1928. California deplores the heavy loss of life and property that this disaster entailed. To prevent a recurrence of a like catastrophe, we believe it imperative that whatever lessons the failure of this dam may teach should be made public for the benefit of the people of our state. It was also our thought that the investigation into the causes of the failure of this dam should be made by an agency that was not in any way connected with the preparation of the plans, the construction, or the operation of the dam. Accordingly a commission of engineers and geologists of expert knowledge and eminent reputation was appointed to make this study. The instructions given its members appear in the body of their report. Despite the arduous service that the investigation required, the members of the commission served without personal compensation to them- selves, thus placing their report upon a high plane of unselfish public service. On behalf of the people of California, I extend to them the thanks of the state. As the future of California depends in a large measure upon the storage of water, and the construction of dams, it is gratifying to note that this report finds that such structures can be built with entire safety when due regard is paid to suitability of foundations and correctness of design. This is the great lesson of the disaster. C. C. Young, Governor of California

pi+ + d --> p + p reaction between 18 and 44 MeV

A study of the reaction pi+ + d --> p + p has been performed in the energy range of 18 - 44 MeV. Total cross sections and differential cross sections at six angles have been measured at 15 energies with an energy increment of 1 - 2 MeV. This is the most systematic data set in this energy range. No structure in the energy dependence of the cross section has been observed within the accuracy of this experiment.Comment: 20 pages, 7 Postscript figure

Growing old, yet staying young: The role of telomeres in bats' exceptional longevity

Understanding aging is a grand challenge in biology. Exceptionally long-lived animals have mechanisms that underpin extreme longevity. Telomeres are protective nucleotide repeats on chromosome tips that shorten with cell division, potentially limiting life span. Bats are the longest-lived mammals for their size, but it is unknown whether their telomeres shorten. Using >60 years of cumulative mark-recapture field data, we show that telomeres shorten with age inRhinolophus ferrumequinumandMiniopterus schreibersii, but not in the bat genus with greatest longevity,Myotis. As in humans, telomerase is not expressed inMyotis myotisblood or fibroblasts. Selection tests on telomere maintenance genes show thatATMandSETX, which repair and prevent DNA damage, potentially mediate telomere dynamics inMyotisbats. Twenty-one telomere maintenance genes are differentially expressed inMyotis, of which 14 are enriched for DNA repair, and 5 for alternative telomere-lengthening mechanisms. We demonstrate how telomeres, telomerase, and DNA repair genes have contributed to the evolution of exceptional longevity inMyotisbats, advancing our understanding of healthy aging

Phenomenology of the Deuteron Electromagnetic Form Factors

A rigorous extraction of the deuteron charge form factors from tensor polarization data in elastic electron-deuteron scattering, at given values of the 4-momentum transfer, is presented. Then the world data for elastic electron-deuteron scattering is used to parameterize, in three different ways, the three electromagnetic form factors of the deuteron in the 4-momentum transfer range 0-7 fm^-1. This procedure is made possible with the advent of recent polarization measurements. The parameterizations allow a phenomenological characterization of the deuteron electromagnetic structure. They can be used to remove ambiguities in the form factors extraction from future polarization data.Comment: 18 pages (LaTeX), 2 figures Feb. 25: minor changes of content and in Table