Results 41 to 50 of about 755 (173)
Rare metal granites and related rocks of the Ukrainian shield [PDF]
Two rare metal leucocratic granites, Perga and Kamennaya complexes, can be distinquished on the Ukrainian shield. The Perga complex consists of medium- and coarse-grained, mainly porphyric, biotite, riebeckite and aegirine granites, granite porphyries ...
K.Y. Esipchuk +2 more
doaj +1 more source
The occurrence of rare earth elements in some Finnish mires [PDF]
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
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
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
Geochronology of the Suomenniemi rapakivi granite complex revisited: Implications of point-specific errors on zircon U-Pb and refined λ87 on whole-rock Rb-Sr [PDF]
Multi-grain isotope dilution and secondary ion microprobe zircon U-Pb as well as wholerock Rb-Sr isotope dilution data on the late Paleoproterozoic Suomenniemi rapakivi granite complex (exposed on the northern flank of the Wiborg batholith in ...
O.T. Rämö, I. Mänttäri
doaj +1 more source
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 Proterozoic granitoids of Finland: Granite types, metallogeny and relation to crustal evolution [PDF]
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
This contribution presents complimentary mineralogical and whole-rock chemical data for the Mullnäset rapakivi massif. Three rock types occur: gabbro, syenite with associated granite and “normal” rapakivi granite, here denoted rapakivi-textured granite ...
Lindh, Anders
core +2 more sources
Rb-Sr whole-rock isotopic study of late Archaean and early Proterozoic granitoid intrusions, Kainuu, Eastern Finland [PDF]
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
In order to expand and popularize knowledge about the stone decoration of Saint Petersburg, we present new data on the mineralogy and petrography of the famous Thunder-Stone, the parts of which were the basis for the monument to Peter the Great – the ...
Andrei G. Bulakh +3 more
doaj +1 more source

