Search

Quarries between Old Radnor and Presteigne, Welsh Borderlands, expose a Silurian nearshore succession, which onlaps a rocky palaeotopography of the Neoproterozoic basement that had been uplifted along the Church Stretton Fault Zone. The succession documents the Aeronian to Sheinwoodian transgression of an island or islands, with the following sequence of events: deposition of shallow marine sandstones (Folly Sandstone Formation), regional uplift, preservation of a rocky shoreline and associated deposits (Dolyhir Rudite Member), deposition of limestones characterized by a profusion of coralline algae and the abundant remains of reefs (Dolyhir and Nash Scar Limestone Formation), and finally deposition of trilobitic silty mudstones (basal Coalbrookdale Formation). Facies analysis, carbon isotope (delta C-13(carb)) values, sequence stratigraphy, and collections of bryozoans, conodonts, thelodonts, and trilobites have been used here as a means of refining our stratigraphic understanding of this unique succession. The revised stratigraphy demonstrates many similarities with the adjoining Midland Platform and the wider Silurian world. Notable features include the globally recognized early Sheinwoodian carbon isotope excursion and sealevel changes of regional and global extent. As one of the best examples of its kind, the palaeoshoreline and nearshore succession of Old Radnor and Presteigne acts as a depositional model for ancient rocky shores worldwide.

Quarries between Old Radnor and Presteigne, Welsh Borderlands, expose a Silurian nearshore succession, which onlaps a rocky palaeotopography of the Neoproterozoic basement that had been uplifted along the Church Stretton Fault Zone. The succession documents the Aeronian to Sheinwoodian transgression of an island or islands, with the following sequence of events: deposition of shallow marine sandstones (Folly Sandstone Formation), regional uplift, preservation of a rocky shoreline and associated deposits (Dolyhir Rudite Member), deposition of limestones characterized by a profusion of coralline algae and the abundant remains of reefs (Dolyhir and Nash Scar Limestone Formation), and finally deposition of trilobitic silty mudstones (basal Coalbrookdale Formation). Facies analysis, carbon isotope (delta C-13(carb)) values, sequence stratigraphy, and collections of bryozoans, conodonts, thelodonts, and trilobites have been used here as a means of refining our stratigraphic understanding of this unique succession. The revised stratigraphy demonstrates many similarities with the adjoining Midland Platform and the wider Silurian world. Notable features include the globally recognized early Sheinwoodian carbon isotope excursion and sealevel changes of regional and global extent. As one of the best examples of its kind, the palaeoshoreline and nearshore succession of Old Radnor and Presteigne acts as a depositional model for ancient rocky shores worldwide.

Quarries between Old Radnor and Presteigne, Welsh Borderlands, expose a Silurian nearshore succession, which onlaps a rocky palaeotopography of the Neoproterozoic basement that had been uplifted along the Church Stretton Fault Zone. The succession documents the Aeronian to Sheinwoodian transgression of an island or islands, with the following sequence of events: deposition of shallow marine sandstones (Folly Sandstone Formation), regional uplift, preservation of a rocky shoreline and associated deposits (Dolyhir Rudite Member), deposition of limestones characterized by a profusion of coralline algae and the abundant remains of reefs (Dolyhir and Nash Scar Limestone Formation), and finally deposition of trilobitic silty mudstones (basal Coalbrookdale Formation). Facies analysis, carbon isotope (delta C-13(carb)) values, sequence stratigraphy, and collections of bryozoans, conodonts, thelodonts, and trilobites have been used here as a means of refining our stratigraphic understanding of this unique succession. The revised stratigraphy demonstrates many similarities with the adjoining Midland Platform and the wider Silurian world. Notable features include the globally recognized early Sheinwoodian carbon isotope excursion and sealevel changes of regional and global extent. As one of the best examples of its kind, the palaeoshoreline and nearshore succession of Old Radnor and Presteigne acts as a depositional model for ancient rocky shores worldwide.

Quarries between Old Radnor and Presteigne, Welsh Borderlands, expose a Silurian nearshore succession, which onlaps a rocky palaeotopography of the Neoproterozoic basement that had been uplifted along the Church Stretton Fault Zone. The succession documents the Aeronian to Sheinwoodian transgression of an island or islands, with the following sequence of events: deposition of shallow marine sandstones (Folly Sandstone Formation), regional uplift, preservation of a rocky shoreline and associated deposits (Dolyhir Rudite Member), deposition of limestones characterized by a profusion of coralline algae and the abundant remains of reefs (Dolyhir and Nash Scar Limestone Formation), and finally deposition of trilobitic silty mudstones (basal Coalbrookdale Formation). Facies analysis, carbon isotope (delta C-13(carb)) values, sequence stratigraphy, and collections of bryozoans, conodonts, thelodonts, and trilobites have been used here as a means of refining our stratigraphic understanding of this unique succession. The revised stratigraphy demonstrates many similarities with the adjoining Midland Platform and the wider Silurian world. Notable features include the globally recognized early Sheinwoodian carbon isotope excursion and sealevel changes of regional and global extent. As one of the best examples of its kind, the palaeoshoreline and nearshore succession of Old Radnor and Presteigne acts as a depositional model for ancient rocky shores worldwide.

Quarries between Old Radnor and Presteigne, Welsh Borderlands, expose a Silurian nearshore succession, which onlaps a rocky palaeotopography of the Neoproterozoic basement that had been uplifted along the Church Stretton Fault Zone. The succession documents the Aeronian to Sheinwoodian transgression of an island or islands, with the following sequence of events: deposition of shallow marine sandstones (Folly Sandstone Formation), regional uplift, preservation of a rocky shoreline and associated deposits (Dolyhir Rudite Member), deposition of limestones characterized by a profusion of coralline algae and the abundant remains of reefs (Dolyhir and Nash Scar Limestone Formation), and finally deposition of trilobitic silty mudstones (basal Coalbrookdale Formation). Facies analysis, carbon isotope (delta C-13(carb)) values, sequence stratigraphy, and collections of bryozoans, conodonts, thelodonts, and trilobites have been used here as a means of refining our stratigraphic understanding of this unique succession. The revised stratigraphy demonstrates many similarities with the adjoining Midland Platform and the wider Silurian world. Notable features include the globally recognized early Sheinwoodian carbon isotope excursion and sealevel changes of regional and global extent. As one of the best examples of its kind, the palaeoshoreline and nearshore succession of Old Radnor and Presteigne acts as a depositional model for ancient rocky shores worldwide.

The techniques of photodissociation-spectroscopy and photofragment spectroscopy were developed and applied to characterize the excited states of a number of important molecular ions that occur in both natural and laboratory discharges and plasmas. Dissociative excited states in O2(+) and NO(+) were identified, together with their predissociation mechanisms, using photofragment spectroscopy techniques. This work yielded an order of magnitude improvement in resolution over conventional spectroscopic techniques, measurements of predissociation lifetimes, and several new observations of molecular dynamics and properties. In NO(+) a complicated band system was found to consist of transitions to predissociated levels of the previously unobserved 2 3 Pi state. These studies will have a major impact on current knowledge of NO(+) excited states. The structure of the OONO(-) isomer of NO3(-) was confirmed, and the probable mechanism for its stabilization in atmospheric reactions was identified as due to clustering with H2O, which preserves its structure and prevents conversion to NO3(-). The possibility that previous observations of CO3(-) photodissociation in a drift tube can be attributed to excited ions was investigated. The results showed that the drift tube CO3(-) ions are in the ground state, but were not able to resolve the discrepancy in the CO3(-) bond dissociation energy.

The transport properties, collisional dissociation, and photodissociation of N4(+) have been measured. The photodissociation cross section of CO3(-) has been interpreted to yield structural information on this ion, including vibrational frequencies, bond energy and electron affinity. A detailed study of the photodissociation of O2(+)(a 4Pi(u)) has been made, leading to the discovery of a new state F 4Pi(g), and of new techniques for high resolution spectroscopy of ions.

Production of negative ions has been identified in laser-generated plasmas containing nitric oxide, sulfur dioxide, or fluorinated benzenes. The mechanism for anion formation is assigned as dissociative attachment of photoelectrons to an excited electronic state of the parent molecule. Keywords: Multiphoton ionization; Capture.

Radiative lifetimes of N2(+)(A doublet Pi(u)) have been determined for vibrational levels v' = 1-8. A time-of-flight method was used to overcome collisional and diffusion effects that have affected most other measurements., Sponsored in part by DARPA.

Absolute cross sections for the deexcitation of He(2 singlet S) and of He(2 triplet S) metastables by N2 and Ar have been measured over the energy interval from 150 to 1600 eV using an optical technique. The (2 singlet S) cross sections are found to be as much as 50% larger than the (2 triplet S) cross sections are nearly equal at these energies. The cross sections all lie in the range of 7-20 sq A and decrease with increasing energy. The ionization total cross sections for He(2 singlet S) + Ar and He(2 triplet S) + Ar have been calculated. (Author)

https://egrove.olemiss.edu/west_union_med/1096/thumbnail.jpg

https://egrove.olemiss.edu/west_union_med/1096/thumbnail.jpg

https://egrove.olemiss.edu/west_union_med/1096/thumbnail.jpg

https://egrove.olemiss.edu/west_union_med/1096/thumbnail.jpg

https://egrove.olemiss.edu/west_union_med/1096/thumbnail.jpg

Correspondence from John Moseley to Dallas McLaren regarding Japanese-American students at Wayne University., The Japanese American Archival Collection documents the people, places, and daily life of Japanese Americans, primarily those who lived in the once thriving community of pre-war Florin in the Sacramento region, as well as the conditions in American incarceration camps during World War II. The approximately 7,000 original items include personal and official letters, photographs, diaries, arts and crafts, newsletters, textiles, camps artifacts, yearbooks and other publications.