Results 11 to 20 of about 59,536 (124)

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

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   +2 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

Igneous and metamorphic processes in the Shap Granite and its aureole [PDF]

open access: yes, 1986
The Shap Granite outcrops in eastern Cumbria, N.W. England and is a post—orogenic granite intruded during the Lower Devonian (ie 394 Ma) into rocks of Ordovician to Siturian age.
Caunt, Stephen Lloyd
core   +7 more sources

The origin of Proterozoic massif-type anorthosites: Evidence from interactions between crustal xenoliths and basaltic magma [PDF]

open access: yes, 1999
Plagioclase-rich reaction zones occur around numerous aluminous crustal xenoliths within a suite of Palaeogene sub-volcanic basic sheets on the Isle of Mull, NW Scotland.
Preston, R.J.   +2 more
core   +7 more sources

Secular Evolution of Continents and the Earth System

open access: yesReviews of Geophysics, Volume 60, Issue 4, December 2022., 2022
Abstract Understanding of secular evolution of the Earth system is based largely on the rock and mineral archive preserved in the continental lithosphere. Based on the frequency and range of accessible data preserved in this record, we divide the secular evolution into seven phases: (a) “Proto‐Earth” (ca. 4.57–4.45 Ga); (b) “Primordial Earth” (ca. 4.45–
Peter A. Cawood   +6 more
wiley   +1 more source

Review on geology and mineralization of North Korea (I: Precambrian)

open access: yesResource Geology, Volume 71, Issue 4, Page 492-513, October 2021., 2021
The Precambrian geotectonic provinces of North Korea contain continental cores and massifs, active continental margins, and rift zones. The Precambrian strata between the eastern North China Craton (NCC) and North Korea are newly correlated considering rearranged stratigraphy in this review.
Bum Han Lee   +3 more
wiley   +1 more source

Hybridization in the subvolcanic Jaala-Iitti complex and its petrogenetic relation to rapakivi granites and associated mafic rocks of southeastern Finland [PDF]

open access: yesBulletin of the Geological Society of Finland, 1995
The 1630 Ma Jaala-Iitti complex is an example of bimodal rapakivi granite magmatism in which the interaction of granite and diabase magmas have led locally to hybridization.
P.T. Salonsaari
doaj   +1 more source

Reconstructing craton‐scale tectonic events via in situ Rb‐Sr geochronology of poly‐phased vein mineralization

open access: yesTerra Nova, Volume 33, Issue 5, Page 502-510, October 2021., 2021
Abstract Fault‐ and fracture‐hosted multi‐stage mineral assemblages that formed by fracture reactivation and fluid migration, constitute archives of the tectonic evolution of Precambrian cratons. Complex intergrowth patterns of these mineral records often hinder absolute dating of mineralization events for geological models.
Mikael Tillberg   +5 more
wiley   +1 more source

Plagioclase-mantled K-feldspar in the Carboniferous porphyritic microgranite of Altenberg-Frauenstein, Eastern Erzgebirge / Krušné Hory [PDF]

open access: yesBulletin of the Geological Society of Finland, 2002
The Upper Carboniferous porphyritic microgranite of Altenberg-Frauenstein, formerly known as Granitporphyr (Dalmer 1896) and here abbreviated as GP, forms a 36 km long and up to 18 km wide complex of ring dykes related to the Teplice-Altenberg caldera in
A. Müller, R. Seltmann
doaj   +1 more source

Home - About - Disclaimer - Privacy