Results 11 to 20 of about 154 (139)

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

Ecol 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, Raitanen H, Nystrand M, Salovius-Laurén S.   +3 more
europepmc   +2 more sources

Hydrogeological Characterization of Crystalline Bedrock Using Borehole Magnetic Resonance

Groundwater, Volume 61, Issue 6, Page 793-815, November/December 2023., 2023
This study is one of the first to test the applicability of the borehole magnetic resonance (BMR) method in crystalline “hard rock” environment. The aim was to investigate whether the BMR measurements could constitute an effective method for investigating detailed permeability variations in the crystalline bedrock of the two study sites: Sakatti mining
Salla Eeva, Aino Karjalainen, Emilia Koivisto, Kirsti Korkka‐Niemi, Anne Rautio, Olli Räisänen, Ryan Gee, Benjamin Birt   +7 more
wiley   +1 more source

The interplay of bedrock fractures and glacial erosion in defining the present‐day land surface topography in mesoscopically isotropic crystalline rocks

Earth Surface Processes and Landforms, Volume 48, Issue 10, Page 1956-1968, August 2023., 2023
In this paper, we link natural fractures with outcrop morphologies and apply the findings in understanding the glacial erosion signatures in crystalline rocks. Abstract This paper addresses the effect of fractures within crystalline bedrock on glacial erosion processes in fast flowing hard bed glacier environments. In particular, we examine (i) whether
Pietari Skyttä, Nicklas Nordbäck, Antti Ojala, Niko Putkinen, Ismo Aaltonen, Jon Engström, Jussi Mattila, Nikolas Ovaskainen   +7 more
wiley   +1 more source

Induced Earthquake Source Parameters, Attenuation, and Site Effects From Waveform Envelopes in the Fennoscandian Shield

Journal of Geophysical Research: Solid Earth, Volume 128, Issue 4, April 2023., 2023
Abstract We analyze envelopes of 233 and 22 ML0.0 to ML1.8 earthquakes induced by two geothermal stimulations in the Helsinki, Finland, metropolitan area. We separate source spectra and site terms and determine intrinsic attenuation and the scattering strength of shear waves in the 3–200 Hz frequency range using radiative transfer based synthetic ...
Tom Eulenfeld, Gregor Hillers, Tommi A. T. Vuorinen, Ulrich Wegler   +3 more
wiley   +1 more source

Secular Evolution of Continents and the Earth System

Reviews 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, Priyadarshi Chowdhury, Jacob A. Mulder, Chris J. Hawkesworth, Fabio A. Capitanio, Prasanna M. Gunawardana, Oliver Nebel   +6 more
wiley   +1 more source

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

Resource 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, Sang‐Mo Koh, Namhoon Kim, Byoung‐Woon You   +3 more
wiley   +1 more source

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

Terra 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, Henrik Drake, Thomas Zack, Johan Hogmalm, Ellen Kooijman, Mats Åström   +5 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]

Bulletin 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

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

Bulletin 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

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

Bulletin 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