Radioactive Methods for Determining Geological Age

Ahrens, L.H.

doi:10.1088/0034-4885/19/1/303

Cited by 11 publications

(2 citation statements)

References 132 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5 In the 1950s and early the 1960s numerous publications appeared in Russian on the results of K-Ar dating and geochronology. In a review of dating methods in 1965, 10 it was noted that the first K-Ar dating was accomplished by Gerling and Yashchenko 11 ''who obtained nine argon ages (mainly on microcline) and who reported satisfactory agreement between argon ages and those of associated minerals determined by the lead and helium methods. ''…”

Section: Historical Aspectsmentioning

confidence: 99%

Gas Source Isotope Ratio Mass Spectrometry for the Analysis of Noble Gases

Assonov

Prohaska

2014

Sector Field Mass Spectrometry for Elemental and Isotopic Analysis

View full text Add to dashboard Cite

Geological processes result in redistribution of noble gases on Earth, with some isotopes being accumulated due to radioactive decay and cosmic irradiation. Therefore noble gas isotope and concentration ratios can be used as tracers of geological processes and geologic age. Analytical techniques for measuring noble gases are complex and differ substantially from the techniques used for stable isotopes. This chapter describes the historical development of noble gas isotope ratio mass spectrometry, sampling requirements, noble gas extraction techniques and sample gas purification and also gives the overview of modern commercially available instruments. Next the referencing strategy and calibration approaches are considered. The only international reference for noble gas isotope ratios is the Earth atmosphere reservoir – an artifact-based scale. In contrast to stable isotopes, noble gas applications require not only relative determinations vs. the international scale but mostly numerical values of isotope and elemental ratios. Up to date many publications refer to the noble gas isotope ratios determined in 1940s. Since then several re-determinations have been reported, being mostly based on commercially available noble gases. Unsolved discrepancies in the isotope ratios, e.g. for atmospheric Ar imply not well-identified uncertainty component for noble gas data which needs more attention. Finally an overview of applications is given.

show abstract

Section: Historical Aspectsmentioning

confidence: 99%

Gas Source Isotope Ratio Mass Spectrometry for the Analysis of Noble Gases

Assonov

Prohaska

2014

Sector Field Mass Spectrometry for Elemental and Isotopic Analysis

View full text Add to dashboard Cite

show abstract

“…THE LEAD-ISOTOPE EVIDENCE Ahrens (1956) and Rankama (1954) gave. summary reports on the use of lead isotopes in dating.…”

Section: Main Period Of Mineralization Age Of the Main Periodmentioning

confidence: 99%

Ore deposits of the Coeur d'Alene district, Shoshone County, Idaho

Fryklund¹,

Weis²

1964

Professional Paper

View full text Add to dashboard Cite

The Coeur d'Alene district of this report is that area in northern Idaho between the Montana State line and longitude 116°17', and between latitudes 47°26'15" and 47°33'45".The country rock of the area consists of the Prichard, Burke, Revett, St. Regis, Wallace, and Striped Peak Formations of the Precambrian Belt Series. These formations are composed of fine-grained quartz-rich rocks that have been mildly regionally metamorphosed and which, in conse• quence now belong to the green schist facies. The ubiquitous sericite was oriented during the folding and metamorphism and the rocks now consist of quartzose slate, sericite phyllite, sericite quartzite, and in a few areas, schistose quartzite and sericite schist.Igneous rocks of the area include monzonite stocks and related monzonite dikes, which were probably intruded at the same time as the Idaho batholith, and biotite lamprophyre, diabase, and porphyritic hornblende-augite-olivine-dikes, the latter perhaps varieties of the diabase dikes. The two stocks are part of a line of northeastward-striking intrusives that apparently lie along a major fracture. This fracture is probably one of the controlling factors in the origin of the Coeur d'Alene district.Several sets of faults can be recognized; there is no certainty that any are older than the shear zones that contain ore deposits, but the great strike-slip faults-the Osburn and Placer Creek faults-have offset mineral belts.Idaho, within which the Coeur d'Alene district is the only important mining area, has ranked second in lead and in zinc production for many years. The first recorded production from the Coeur d'Alene district proper was

show abstract

Some aspects of radiogeology

Davidson

1961

Geological Journal

View full text Add to dashboard Cite

SUMMARYWithin recent years studies of the natural distribution pattern of the radioactive elements have been developed as a prerequisite to explorations for the raw materials of atomic energy. One imponant result of this activity is an improvement of our geochronological knowledge of the stratigraphical succession. Memorable bench-marks are Lower Cambrian at 600 million years, Upper Carboniferous at 300 my., Middle Cretaceous at I00 m.y. S o -d e dProterozoic rocks may locally be more than 2,000 m.y. old (Witwatersrand System) and may pre-date several orogenies in so-called Archaean rocks elsewhere. Some ore deposits provide factual evidence for theories of reworking: for example, ores apparencly of late Mesozoic age can derive from Hercynian granites. Radiogeological studies now play an important p m in prospecting for ore deposits and for coal and oil fields, and they can be of much significance in evaluating the health hazards arising from artificial radioactiviry.In a centenary lecture to a learned society it is customary to review the progress made in some relevant branch of science throughout the preceding hundred years. Manifestly your Council's request for an address on radiogeology cannot be dealt with in this orthodox manner, for the Liverpool Geological Society whose centenary we now celebrate was far from being in its first flush of youth when the phenomenon of radioactivity was discovered in the closing years of last century. But no scientific investigation in the history of mankind has set off a greater chain reaction of derivative researches than the Curies' epoch-making studies on the properties of uranium and thorium minerals; and the advances in our knowledge of the earth stemming directly or indirectly from this discovery of radioactivity are such that the relatively new field of radiogeology (or, as it is sometimes termed, nuclear geology) has become a science in its own right, certainly with no less influence on human affairs than have its cousins nuclear physics, radiochemisq, and radiobiology.The term radiogeology was introduced into geological literature in 1924 by the Russian geochemist Vernadsky, to denote the branch of knowledge concerned with the distribution pattern of the radioactive elements throughout the earth's crust and with the role of radioactive processes in geological phenomena. Consequent to the world-wide explorations for uranium initiated twenty years later, interest in these topics has so expanded and flourished that today the literature of the subject extends to close on a hundred text-books and well over 10,000 papers. Since I am enjoined not to exceed 10,000 words in this review, 312 C. P. DAVIDSON I can do no more than lay before you a few disjointed observations sufKciently diverse in their nature to have more than a specialized appeal. One cannot of course write on radiogeology without reference at some length to the part it has played in establishing the age of the earth and the geochronology of the stratigraphical succession; but in addition radioactivity stud...

show abstract

Radioactive Methods for Determining Geological Age

Cited by 11 publications

References 132 publications

Gas Source Isotope Ratio Mass Spectrometry for the Analysis of Noble Gases

Gas Source Isotope Ratio Mass Spectrometry for the Analysis of Noble Gases

Ore deposits of the Coeur d'Alene district, Shoshone County, Idaho

Some aspects of radiogeology

Contact Info

Product

Resources

About