Results 11 to 20 of about 755 (173)

Boulder of orbicular rapakivi in Taivassalo, southwestern Finland [PDF]

open access: yesBulletin of the Geological Society of Finland, 1983
A boulder of an orbicular rapakivi was found in Taivassalo, close to the southern contact of the Vehmaa rapakivi area in southwestern Finland. Many features, e.g.
N. Edelman
doaj   +3 more sources

A specialized topaz-bearing rapakivi granite and associated mineralized greisen in the Ahvenisto complex, SE Finland [PDF]

open access: yesBulletin of the Geological Society of Finland, 1991
The Ahvenisto rapakivi complex is a satellite northwest of the large Wiborg rapakivi batholith in Southeastern Finland. The rapakivi rocks are surrounded by rapakivi-age gabbros, anorthosites, monzodiorites and diabases.
P. Edén
doaj   +2 more sources

Weathering in the Wyborg rapakivi area, southeastern Finland

open access: yesFennia: International Journal of Geography, 1985
Field survey of weathering sites in the Wyborg rapakivi area indicates that saprolites are far more common in the central part of the massif than in the marginal areas. Many till‑covered saprolites and parautochthonous crust‑tills prove the weathering to
Aimo Kejonen
doaj   +2 more sources

Miarolitic cavities in rapakivi granite on Hästholmen, Loviisa, southeastern Finland [PDF]

open access: yesBulletin of the Geological Society of Finland, 1987
Miarolitic cavities are described from drill cores taken from rapakivi granite on Hästholmen, an island about 80 km east of Helsinki. The distribution of cavities between different textural types of rapakivi seems to favour the equigranular medium to ...
K. Lindqvist, V. Suominen
doaj   +2 more sources

Magmatic constraints on localization of natural stone deposits in the Vehmaa rapakivi granite batholith, southwestern Finland [PDF]

open access: yesBulletin of the Geological Society of Finland, 2011
The 1580–1570 Ma old Vehmaa rapakivi granite batholith was studied with the aim to define the geological constraints for localization of natural stone deposits in the batholith.
O. Selonen   +3 more
doaj   +2 more sources

Sediment Characteristics in Stonewort <i>Chara Tomentosa</i> Assemblages. [PDF]

open access: yesEcol Evol
The study investigated sediment characteristics associated with Chara tomentosa. The results show that sediment grain size and the concentration of the dissolved phosphate in the porewater differ in the seafloor areas characterised by C. tomentosa from adjacent areas at similar depth, but without charophytes.
Puttonen I   +3 more
europepmc   +2 more sources

Earth's anomalous middle-age magmatism driven by plate slowdown [PDF]

open access: yesScientific Reports, 2022
The mid-Proterozoic or "boring billion" exhibited extremely stable environmental conditions, with little change in atmospheric oxygen levels, and mildly oxygenated shallow oceans.
C. O’Neill   +3 more
doaj   +2 more sources

Surface weathering of rapakivi granite outcrops – implications for natural stone exploration and quality evaluation [PDF]

open access: yesEstonian Journal of Earth Sciences, 2008
Implications of surface weathering of rapakivi granite outcrops for natural stone evaluation were studied in the Wiborg rapakivi granite batholith in southeastern Finland.
Härmä, Paavo, Selonen, Olavi
doaj   +1 more source

Rapakivi K‐Feldspar Megacrysts in Monzogranitic Porphyry: Evidence for Magma Recharge and Mush Rejuvenation

open access: yesGeochemistry, Geophysics, Geosystems
The formation, storage, and evolution of granitic magmas are fundamental processes driving the growth of continental crust. While traditionally attributed to crystal fractionation in high‐melt fraction magma chambers, the model invoking low‐melt fraction
Wang Li   +5 more
doaj   +2 more sources

Fluid history from crystal cavities in rapakivi, Pyterlahti, southeastern Finland [PDF]

open access: yesBulletin of the Geological Society of Finland, 1987
The crystal cavities lined with quartz, feldspars, biotite, fluorite and a number of accessory phases occurring in the Haikonvuori pyterlite quarry in the Wiborg rapakivi massif were studied with mineralogical, petrographical and chemical methods ...
K. Kinnunen, K. Lindqvist, R. Lahtinen
doaj   +2 more sources

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