Search Results - "Horan, Mary F."

Preservation of Earth-forming events in the tungsten isotopic composition of modern flood basalts by Rizo, Hanika, Walker, Richard J., Carlson, Richard W., Horan, Mary F., Mukhopadhyay, Sujoy, Manthos, Vicky, Francis, Don, Jackson, Matthew G.

“…How much of Earth's compositional variation dates to processes that occurred during planet formation remains an unanswered question. High-precision tungsten…”
Get full text

Contributors to chromium isotope variation of meteorites by Qin, Liping, Alexander, Conel M.O’D., Carlson, Richard W., Horan, Mary F., Yokoyama, Tetsuya

“…We report the results of a comprehensive, high precision survey of the Cr isotopic compositions of primitive chondrites, along with some differentiated…”
Get full text

Chemical Separation of Tungsten and Other Trace Elements for TIMS Isotope Ratio Measurements Using Organic Acids by Peters, Bradley J., Mundl‐Petermeier, Andrea, Horan, Mary F., Carlson, Richard W., Walker, Richard J.

“…One requirement for isotope ratio measurement results with small measurement uncertainties is that the element of interest is effectively separated from the…”
Get full text

Chemical and chronologic complexity in the convecting upper mantle: Evidence from the Taitao ophiolite, southern Chile by Schulte, Ruth F., Schilling, Manuel, Anma, Ryo, Farquhar, James, Horan, Mary F., Komiya, Tsuyoshi, Piccoli, Philip M., Pitcher, Lynnette, Walker, Richard J.

“…Exposure of the ca. 6 Ma Taitao ophiolite, Chile, located ∼50 km south of the Chile Triple Junction, allows detailed chemical and isotopic study of rocks that…”
Get full text

Factors influencing the precision and accuracy of Nd isotope measurements by thermal ionization mass spectrometry by Garçon, Marion, Boyet, Maud, Carlson, Richard W., Horan, Mary F., Auclair, Delphine, Mock, Timothy D.

“…Taking the example of Nd, we present a method based on a 4-mass-step acquisition scheme to measure all isotope ratios dynamically by thermal ionization mass…”
Get full text

Tungsten-182 evidence for an ancient kimberlite source by Nakanishi, Nao, Giuliani, Andrea, Carlson, Richard W., Horan, Mary F., Woodhead, Jon, Pearson, D. Graham, Walker, Richard J.

“…Globally distributed kimberlites with broadly chondritic initial 143Nd-176Hf isotopic systematics may be derived from a chemically homogenous, relatively…”
Get full text

Residual platinum-group minerals from highly depleted harzburgites of the Lherz massif (France) and their role in HSE fractionation of the mantle by Luguet, Ambre, Shirey, Steven B., Lorand, Jean-Pierre, Horan, Mary F., Carlson, Richard W.

“…In order to constrain the highly siderophile elements (HSE: Re and platinum group elements (PGE: Os, Ir, Ru, Pt and Pd)) host mineral(s) in refractory, base…”
Get full text

Osmium-187 Enrichment in Some Plumes: Evidence for Core-Mantle Interaction? by Walker, Richard J., Morgan, John W., Horan, Mary F.

“…Calculations with data for asteroidal cores indicate that Earth's outer core may have a rhenium/osmium ratio at least 20 percent greater than that of the…”
Get full text

Subduction-modified oceanic crust mixed with a depleted mantle reservoir in the sources of the Karoo continental flood basalt province by Heinonen, Jussi S., Carlson, Richard W., Riley, Teal R., Luttinen, Arto V., Horan, Mary F.

“…The great majority of continental flood basalts (CFBs) have a marked lithospheric geochemical signature, suggesting derivation from the continental…”
Get full text

Hadean silicate differentiation preserved by anomalous 142Nd/144Nd ratios in the Réunion hotspot source by Peters, Bradley J., Carlson, Richard W., Day, James M. D., Horan, Mary F.

“…Neodymium-142 isotope data from young Réunion Island volcanic rocks reflect the effects of geological processes that occurred more than four billion years ago,…”
Get full text

History of crustal growth in Africa and the Americas from detrital zircon and Nd isotopes in glacial diamictites by Gaschnig, Richard M., Horan, Mary F., Rudnick, Roberta L., Vervoort, Jeffrey D., Fisher, Christopher M.

“…•Detrital zircon age and Hf isotope and whole-rock Nd isotope data are provided for Mesoarchean, Paleoproterozoic, Neoproterozoic, and Paleozoic glacial…”
Get full text

Rheniumum concentration and isotope systematics in group IIAB iron meteorites by Morgan, John W., Horan, Mary F., Walker, Richard J., Grossman, Jeffrey N.

“…Rhenium and osmium abundances, and osmium isotopic compositions were measured by negative thermal ionization mass spectrometry in thirty samples, including…”
Get full text

The komatiite testimony to ancient mantle heterogeneity by Puchtel, Igor S., Blichert-Toft, Janne, Horan, Mary F., Touboul, Mathieu, Walker, Richard J.

“…Komatiites are crystallized samples of high-temperature, high-MgO lavas that were common during the Archean, but became increasingly rarer in the Proterozoic…”
Get full text

Re–Os isotopic constraints on magma mixing in the Peridotite Zone of the Stillwater Complex, Montana, USA by Horan, Mary F., Morgan, John W., Walker, Richard J., Cooper, Roger W.

“…A study was undertaken to better constrain variation in Os initial isotopic ratios within and between chromite layers of the Peridotite Zone of the Stillwater…”
Get full text

Correlated cosmogenic W and Os isotopic variations in Carbo and implications for Hf–W chronology by Qin, Liping, Dauphas, Nicolas, Horan, Mary F., Leya, Ingo, Carlson, Richard W.

“…An obstacle for establishing the chronology of iron meteorite formation using 182Hf–182W systematics (t1/2=8.9Myr) is to find proper neutron fluence monitors…”
Get full text

Hadean silicate differentiation preserved by anomalous ^sup 142^Nd/^sup 144^Nd ratios in the Réunion hotspot source by Peters, Bradley J, Carlson, Richard W, Day, James M D, Horan, Mary F

“…Active volcanic hotspots can tap into domains in Earth's deep interior that were formed more than two billion years ago1,2. High-precision data on variability…”
Get full text

Hadean silicate differentiation preserved by anomalous 142Nd/144Nd ratios in the Runion hotspot source by Peters, Bradley J, Carlson, Richard W, Day, James M. D, Horan, Mary F

Get full text

Osmium isotopic constraints on the age of lithospheric mantle beneath northeastern China by Wu, Fu-yuan, Walker, Richard J., Ren, Xiang-wen, Sun, De-you, Zhou, Xin-hua

“…Northeastern China is composed of the Paleozoic Xing'an Mongolian Orogenic Belt (XMOB) in the north, and the Archean North China Craton (NCC) in the south…”
Get full text

Highly siderophile elements in chondrites by Horan, M.F., Walker, R.J., Morgan, J.W., Grossman, J.N., Rubin, A.E.

“…The abundances of the highly siderophile elements (HSE), Re, Os, Ir, Ru, Pt and Pd, were determined by isotope dilution mass spectrometry for bulk samples of…”
Get full text

The nature of metasomatism in the sub-arc mantle wedge: evidence from Re–Os isotopes in Kamchatka peridotite xenoliths by Widom, Elisabeth, Kepezhinskas, Pavel, Defant, Mark

“…We have performed Re–Os isotope measurements on a suite of 21 Kamchatka mantle xenoliths including 19 harzburgites and two lherzolites, from the northern arc…”
Get full text