Results 51 to 60 of about 3,709 (226)

Anomalous supply of bioessential molybdenum in mid-Proterozoic surface environments [PDF]

open access: yes, 2016
We are grateful to A. Sandison and W. Thayalon for skilled technical support, and Mike Porter and an anonymous reviewer, who helped to clarify the manuscript.Peer ...
Lindgren, Paula, Parnell, John
core   +1 more source

The occurrence of rare earth elements in some Finnish mires [PDF]

open access: yesBulletin of the Geological Society of Finland, 1995
The content of the more abundant rare earths (RE) (Y, La, Ce, Pr, Nd and Sm) in the ash of 399 peat samples from 26 Finnish mires was determined by X-ray fluorescence spectrometry.
I. Yliruokanen, S. Lehto
doaj   +1 more source

Reconstructing Depositional Rates and Their Effect on Paleoenvironmental Proxies: The Case of the Lau Carbon Isotope Excursion in Gotland, Sweden

open access: yesPaleoceanography and Paleoclimatology, Volume 35, Issue 12, December 2020., 2020
Abstract Variations in depositional rates affect the temporal depositional resolutions of proxies used for paleoenvironmental reconstructions; for example, condensation can make reconstructed environmental changes appear very abrupt. This is commonly addressed by transforming proxy data using age models, but this approach is limited to situations where
E. Jarochowska   +5 more
wiley   +1 more source

Rapakivi granites [PDF]

open access: yesGeology Today, 2007
Rapakivi granites, especially the famous rapakivis from southern Finland, are some of the most attractive building and decorative stones, used world‐wide because of their striking textures and beautiful colours. But rapakivi granites are more than just building material, they have also been studied scientifically for over 100 years to try to explain ...
openaire   +1 more source

The 1.24–1.21 Ga Licheng Large Igneous Province in the North China Craton: Implications for Paleogeographic Reconstruction

open access: yesJournal of Geophysical Research: Solid Earth, Volume 125, Issue 4, April 2020., 2020
Abstract Detailed geochronological, geochemical, and paleomagnetic studies of mafic dyke swarms, often associated with mantle plumes, can provide unique constraints on paleogeographic reconstructions. Mafic dykes with baddeleyite U–Pb ages of 1,233 ± 27 Ma (SIMS), 1,206.7 ± 1.7 Ma (TIMS), 1,214.0 ± 4.9 Ma (TIMS), and 1,236.3 ± 5.4 Ma (TIMS) have been ...
Chong Wang   +7 more
wiley   +1 more source

The Proterozoic granitoids of Finland: Granite types, metallogeny and relation to crustal evolution [PDF]

open access: yesBulletin of the Geological Society of Finland, 1986
The granitoids are divided into four main groups: synkinematic (1860‒1930 Ma, most commonly 1870‒1890 Ma), late-kinematic (1800‒1850 Ma) and postkinematic (ca. 1800 Ma) Svecokarelian granitoids, and anorogenic rapakivi granites (1540‒1700 Ma).
P.A. Nurmi, I. Haapala
doaj   +1 more source

The crystalline basement of Estonia: rock complexes of the Palaeoproterozoic Orosirian and Statherian and Mesoproterozoic Calymmian periods, and regional correlations [PDF]

open access: yes, 2009
New data on the Fennoscandian Shield and the Baltic area suggest a need for reinterpretation of the stratigraphy of Estonian Precambrian rock complexes.
Kirs, Juho   +7 more
core   +1 more source

Rb-Sr whole-rock isotopic study of late Archaean and early Proterozoic granitoid intrusions, Kainuu, Eastern Finland [PDF]

open access: yesBulletin of the Geological Society of Finland, 1988
A tonalite-granodiorite-granite suite emplaced during the late Archaean D3 deformational phase yields a six point isochron age of 2,500 ± 270 Ma and an initial 87Sr/86Sr of 0.7044 ±0.0018.
A.N. Halliday   +2 more
doaj   +1 more source

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