Pre-1.91 Ga deformation and metamorphism in the Palaeoproterozoic Vammala Migmatite Belt, southern Finland, and implications for Svecofennian tectonics [PDF]
A metamorphic event in the Vammala Migmatite Belt (VMB) at ~1.92 Ga, revealed by SHRIMP U-Pb analyses of both zircon overgrowths and monazite, is interpreted as post-depositional and is correlated with the development of the early high-grade schistosity.
R.W.R. Rutland +2 more
doaj +1 more source
The age of the ferropicritic volcanics and comagmatic Ni-bearing intrusions at Pechenga, Kola Peninsula, U.S.S.R. [PDF]
Sm-Nd, Pb-Pb and U-Pb isotopic results are presented for samples from the Pilgujärvi Suite of the Pechenga Series. Whole rock samples and clinopyroxenes of ferropicritic volcanics yield a Sm-Nd isochron age of 1990 ± 66 Ma with εNd + 1.6 ± 0.4.
E. Hanski +3 more
doaj +1 more source
A note on a thermokarst feature on the North Slope of Alaska [PDF]
A thermokarst depression with active thermal erosion on one margin and a drainage way to the Sagavanirktok River is described with the aid of a sketch plan and sections.
R.G. West, J.J. Donner, T. Kankainen
doaj +1 more source
SIMS zircon ages and Nd isotope systematics of the 2.2 Ga mafic intrusions in northern and eastern Finland [PDF]
Using the SIMS, ID-TIMS and Sm-Nd isotopic methods and the electron microprobe, we have studied several differentiated mafic intrusions of the c. 2.2 Ga gabbro-wehrlite association (GWA) from four Paleoproterozoic schist belts and the Archean Kuhmo ...
E. Hanski, H. Huhma, J. Vuollo
doaj +1 more source
U-Pb zircon geochronology of selected Archaean migmatites in eastern Finland [PDF]
U-Pb SIMS data on eight samples (four mesosome-leucosome pairs) from migmatites in gneiss complexes are presented from the western part of the Archaean Karelian craton, eastern Finland. Most zircon grains in the mesosomes yield ages between 2.84 Ga and 2.
A. Käpyaho +2 more
doaj +1 more source
Age and isotopic fingerprints of some plutonic rocks in the Wiborg rapakivi granite batholith with special reference to the dark wiborgite of the Ristisaari Island [PDF]
The mid-Proterozoic, locus classicus Wiborg rapakivi granite batholith of southeastern Finland and adjacent Russia comprises a varying, bimodal (silicic-basic) sequence of plutonic, subvolcanic, and volcanic rocks. At the current level of erosion silicic
O.T. Rämö +5 more
doaj +1 more source
Temporal and Hf isotope geochemical evolution of southern Finnish Lapland from 2.77 Ga to 1.76 Ga [PDF]
The southern Finnish Lapland area in the central part of the Fennoscandian shield is a geologically complex zone comprising several Archean blocks and Paleoproterozoic supracrustal belts all of which are intruded by voluminous Paleoproterozoic granites ...
L.S. Lauri +3 more
doaj +1 more source
Absolute mean forecast errors (daily admissions) in England by age band (lowest errors in each age band highlighted in bold).
Andre Charlett (125456) +7 more
core +1 more source
Absolute Value Equations [PDF]
We investigate existence and nonexistence of solutions for NP-hard equations in- volving absolute values of variables: Ax ? |x| = b, where A is an arbitrary n n real matrix.
Mangasarian, Olvi +3 more
core +1 more source
A pilot Rb-Sr dating of the Suomusjärvi ultramylonite: evidence for major post-Svecofennian deformation in SW Finland [PDF]
The Suomusjärvi shear zone in the West Uusimaa area in the Proterozoic Svecofennides of SW Finland belongs to a group of late, post-peak metamorphic structures comprising vertical shear zones and folds with vertical fold axes.
M. Ploegsma
doaj +1 more source

