998 resultados para Uranium-series Dating
Resumo:
The first volume of the College Papers contains original documents dating from 1651 to 1763. It also contains documents dating from 1787, 1817, and 1889, a 1886 photograph of the Charter of 1650, 19th century manscript and 20th century photostat copies of original documents. The documents span the tenures of presidents Increase Mather, John Leverett, Benjamin Wadsworth, and Edward Holyoke.
Resumo:
The second volume of the College Papers contains original documents dating from 1764 to 1785, spanning the tenures of presidents Edward Holyoke, Samuel Locke, Samuel Langdon, acting president Edward Wigglesworth, and Joseph Willard, as well as treasurers Thomas Hubbard, John Hancock, and Ebenezer Storer. It also contains a document from 1793.
Resumo:
The third volume of the College Papers contains original documents dating from 1785 to 1796, spanning the tenures of president Joseph Willard and treasurer Ebenezer Storer. The series chiefly consists of incoming correspondence for Storer.
Resumo:
The fourth volume of the College Papers contains original documents dating from 1797 to 1805, spanning the tenures of president Joseph Willard, acting president Eliphalet Pearson, and treasurer Ebenezer Storer. It chiefly consists of incoming correspondence for Storer.
Resumo:
The fifth volume of College Papers contains original documents dating from 1805 to 1809, spanning the tenures of president Samuel Webber and treasurers Ebenezer Storer and Jonathan Jackson.
Resumo:
The sixth volume of College Papers contains original documents dating from 1809 to 1811, spanning the tenures of presidents Samuel Webber and John Thornton Kirkland, and treasurers Jonathan Jackson and John Davis. Much of the volume consists of general administrative correspondence exchanged between Kirkland and Davis.
Resumo:
The seventh volume of the College Papers contains original documents dating from 1811 to 1815, spanning the tenures of president John Thornton Kirkland and treasurer John Davis. Much of the volume consists of general administrative correspondence exchanged between Kirkland and Davis. It also contains one document from 1819.
Resumo:
The eighth volume of College Papers contains original documents dating from 1815 to 1819, spanning the tenures of president John Thornton Kirkland and treasurer John Davis. Much of the volume consists of general administrative correspondence exchanged between Kirkland and Davis. It also contains a document from 1820.
Resumo:
The ninth volume of College Papers contains original documents dating from 1819 to 1821, spanning the tenures of president John Thornton Kirkland and treasurer John Davis, as well as correspondence between Davis and Steward Stephen Higginson. Much of the volume consists of general administrative correspondence exchanged between Kirkland and Davis. It also contains an early 20th century typewritten document.
Resumo:
The tenth volume of College Papers contains original documents dating from 1821 to 1824, spanning the tenures of president John Thornton Kirkland and treasurer John Davis. Much of the volume consists of general administrative correspondence exchanged between Kirkland and Davis, as well as correspondence between Davis and Steward Stephen Higginson. It also contains a printed document from 1831, during the tenure of president Josiah Quincy.
Resumo:
This paper focuses on the different forms of action adopted by extreme right organizations (both political parties and non-party groups) in Italy and Spain during their recent mobilization and links them to the environmental conditions and internal organizational factors which might affect them. With particular attention paid to the actors’ perceptions of reality, the macro-level factors (such as the favourable or unfavourable political opportunities of the context, the availability of allies in power, the degree of repression by authorities, etc.) as well as the meso-level factors (such as the internal characteristics of extreme right groups and their dynamics) will be explored in order to understand the action strategies of extreme right organizations and their recourse to violence. This paper, drawing on a combination of qualitative and quantitative research techniques, will be based on 20 semi-structured interviews with extreme right representatives of the main right wing organizations in Italy and Spain as well as a protest event analysis of newspapers dating from 2005 to 2009.
Resumo:
A new chemical procedure for cleaning marine carbonates was applied to remove detritus as well as metaloxide contaminations of marine shells from Eemian deposits and adjoining succession of a sediment core from Dagebüll, Schleswig- Holstein. Hence, one can significantly reduce the contamination with detrital uranium and thorium. Thermal ionisation mass spectrometry was applied to determine the uranium and thorium activities used for 230Th/U dating of these shells. At least ten samples of marine bivalves of five different core sections were analysed. Samples located below a five meter thick clay layer at 19-24 m yielded an average age of 132±18 ka. Shells located above the clays at 15-20 m depth were strongly influenced by percolating groundwaters of an open system. Therefore, a reliable dating of these samples was not possible.
Resumo:
Absolute ages of plutonic rocks from mid-ocean ridges provide important constraints on the scale, timing and rates of oceanic crustal accretion, yet few such rocks have been absolutely dated. We present 206Pb/238U SHRIMP zircon ages from two ODP Drill Holes and a surface sample from Atlantis Bank on the Southwest Indian Ridge. We report ten new sample ages from 26-1430 m in ODP Hole 735B, and one from 57 m in ODP Hole 1105A. Including a previously published age, eleven samples from Hole 735B yield 206Pb/238U zircon crystallization ages that are the same, within error, overlap with the estimated magnetic age and are inferred to date the main period of crustal growth, the average age of analyses is 11.99 ± 0.12 Ma. Any differences in the ages of magmatic series and/or tectonic blocks within Hole 735B are unresolvable and eight well-constrained ages vary from 11.86 ± 0.20 Ma to 12.13 ± 0.21 Ma, a range of 0.27 ± 0.29 Ma, consistent with the duration of crustal accretion observed at the Mid-Atlantic Ridge. An age of 11.87 ± 0.23 Ma from Hole 1105A is within error of ages from Hole 735B and permits previous correlations made between zones of oxide-rich gabbros in each hole. Pb/U zircon ages > 0.5 Ma younger than the magnetic age are recorded in at least three samples from Atlantis Bank, one from Hole 735B and two collected along a fault scarp to the East. These young ages may date one or more off-axis events previously suggested from thermochronologic data and support the interpretation of a complex geological history following crustal accretion at Atlantis Bank. Together with results from the surface of Atlantis Bank, dating has shown that while the majority of Pb/U SHRIMP zircon ages record the short-lived (< 0.5 Ma) phase of crustal accretion on-axis, results from several samples precede and post-date this period by > 1 Ma suggesting a complex and prolonged magmatic/tectonic history for the crust at Atlantis Bank.
Resumo:
"U.S. AEC Contract No. AT-(40-1)-1337".