Results 41 to 50 of about 5,717 (242)

Continental weathering as the source of iron in Jurassic iron oolites from Switzerland

Swiss Journal of Geosciences, 2023
Iron is extremely insoluble in oxic seawater. The lack of a large aqueous reservoir means that sediments rich in authigenic iron are rare in the modern ocean.
Stefan Schunck, Jörg Rickli, Stephan Wohlwend, Helmut Weissert, Derek Vance   +4 more
doaj   +1 more source

Cosmogenic and Radiogenic Isotopes [PDF]

Nature, 1964
Radioactive Dating (Proceedings of the Symposium held by the International Atomic Energy Agency in co-operation with the Joint Commission on Applied Radioactivity (ICSU) in Athens, 19–23 November 1962.) (Proceedings Series.) Pp viii + 440. (Vienna : International Atomic Energy Agency; London: H.M.
openaire   +1 more source

The Capitanian Minimum: A Unique Sr Isotope Beacon of the Latest Paleozoic Seawater

Frontiers in Earth Science, 2021
The long-term trend in the Paleozoic seawater 87Sr/86Sr was punctuated by a unique episode called the “Capitanian minimum” at the end of the Guadalupian (Permian; ca. 260 Ma).
Tomomi Kani, Yukio Isozaki
doaj   +1 more source

Coupled Hf-Nd-Pb isotope co-variations of HIMU oceanic island basalts from Mangaia, Cook-Austral islands, suggest an Archean source component in the mantle transition zone [PDF]

, 2013
Although it is widely accepted that oceanic island basalts (OIB) sample geochemically distinct mantle reservoirs including recycled oceanic crust, the composition, age, and locus of these reservoirs remain uncertain. OIB with highly radiogenic Pb isotope
Arculus, Richard J., van Westrenen, W.; id_orcid, Wille, Martin, Eggins, Stephen M., Wille, M., Nebel-Jacobsen, Yona J., Nebel, Oliver, Eggins, S.M., Jenner, F.E., Arculus, R.J., van Westrenen, W., Woodhead, Jon D., Woodhead, J.D., Jenner, Frances E., Nebel, O., Nebel-Jacobsen, Y.J., van Westrenen, Wim   +16 more
core   +1 more source

Mg and Li Stable Isotope Ratios of Rocks, Minerals, and Water in an Outlet Glacier of the Greenland Ice Sheet

Frontiers in Earth Science, 2019
Magnesium and lithium stable isotope ratios (δ26Mg and δ7Li) have shown promise as tools to elucidate biogeochemical processes both at catchment scales and in deciphering global climate processes.
Ruth S. Hindshaw, Jörg Rickli, Julien Leuthold   +2 more
doaj   +1 more source

A normalised seawater strontium isotope curve: possible implications for Neoproterozoic-Cambrian weathering rates and the further oxygenation of the Earth [PDF]

, 2007
The strontium isotope composition of seawater is strongly influenced on geological time scales by changes in the rates of continental weathering relative to ocean crust alteration.
Shields, GA, Shields, G. A.
core  

A Reassessment of Petrochemistry of ~1.2 Ga Tonalitic Rocks of the Northern Tugela Terrane, Natal Metamorphic Belt, South Africa: Further Constraints on the Evolution of This Belt

Geological Journal, EarlyView.
Our petrochemical studies on ~1.2 Ga granitoids of the Natal Metamorphic Belt, South Africa, do not suggest any property similar to Phanerozoic‐style subduction‐related granitoids. Plot of Kotongweni Tonalite in Y versus Sr diagram (after Moyen 2011), note that most samples have Sr/Y < 50.
Palesa Leuta, Saumitra Misra, Thembiso O. Basupi   +2 more
wiley   +1 more source

(Table DR1) Argon isotope data and dating for individual >63 µm amphibole grains from Labrador Sea sediments, ODP Hole 105-647A [PDF]

, 2004
Variations of global and regional silicate weathering rates and paleo-ocean circulation patterns are estimated by using radiogenic isotope records, but the effects of changes in provenance are generally ignored.
Reynolds, Ben C, Burton, Kevin W, Kelley, Simon P, Simon P Kelley (7910837), Kevin W Burton (6965483), Ben C Reynolds (6983228), Sarah C Sherlock (7910834), Sherlock, Sarah C   +7 more
core   +1 more source

Apatite in Carbonatite Preserving Primary Magmatic, Post‐Magmatic Overgrowth, and Post India‐Asia Collision‐Related Hydrothermal Alteration: Evidenced From U–Pb Isotope and Trace Element Geochemistry

Geological Journal, EarlyView.
U–Pb isotope and trace element geochemistry of apatite from carbonatites of Peshawar Plain Alkaline Igneous Province, western Himalaya shows Permo‐Carboniferous magmatism, an additional magmatic pulse during Cretaceous, and post‐magmatic hydrothermal/metasomatism during Oligocene. ABSTRACT U–Pb isotope and trace element geochemistry of apatite combined
Mehboob ur Rashid, Hafiz U. Rehman, Hao‐Yang Lee, Sun‐Lin Chung, Kaushik Das, Kazumasa Aoki, Muhammad Jawad Zeb, Nasir Ahmad, Muhammad Hussain, Hiroshi Yamamoto   +9 more
wiley   +1 more source

(Table 2) Radiogenic, radioactive and stable isotope data for South East Rift samples plus six new Manus Spreading Centre samples [PDF]

, 2015
(Table 2) Radiogenic, radioactive and stable isotope data for South East Rift samples plus six new Manus Spreading Centre ...
Christoph Beier (6973508), S Turner (7997585), Woodhead, Jon D, Wolfgang Bach (6960488), D Niedermeier (6983003), Beier, Christoph, Krumm, Stefan H, Niedermeier, D, Bach, Wolfgang, Jon D Woodhead (6983006), Turner, Stephnie, Stefan H Krumm (6973514), Jörg Erzinger (6960626), Erzinger, Jörg   +13 more
core   +1 more source