Results 71 to 80 of about 3,972 (218)

Distinct Fracture Mineralogy That is Out of Equilibrium With Modern Groundwaters Provides Important Context for Subsurface Life

Journal of Geophysical Research: Biogeosciences, Volume 130, Issue 10, October 2025.
Abstract Rock fracture surfaces in the crust are essential habitat for microorganisms. Fracture‐groundwater interfaces provide physical substrates for biofilm growth and are sources of carbon, nutrients, and electron donors and acceptors. To better understand geochemical processes impacting fracture surfaces and the subsurface microbiome, we identified
Christopher J. Schuler, Sarah L. Nicholas, Ryan Tappero, Dean M. Peterson, Cara M. Santelli, Brandy M. Toner   +5 more
wiley   +1 more source

De Geer moraine internal architecture based on sedimentological and geophysical investigations and implications for ice‐marginal reconstructions

Boreas, Volume 54, Issue 4, Page 687-710, October 2025.
De Geer moraines may act as valuable ice‐marginal indicators; however, to date, their variable mode of formation has presented challenges for this utility. Here, we present sedimentological and ground penetrating radar data of DGMs located in southwest Finland.
Gwyneth E. Rivers, Robert D. Storrar, Antti E. K. Ojala, Joni Mäkinen, Camilla Holmroos, Naomi Holmes   +5 more
wiley   +1 more source

Formation mechanism of the Vaasa Batholith in the Fennoscandian shield: Petrographic and geochemical constraints [PDF]

Bulletin of the Geological Society of Finland, 2012
The ~1.88 Ga Vaasa Batholith in western Finland is a large granitoid area (8 000 km2) with gradational contacts against the garnet- and cordierite-bearing diatexite and metatexite migmatites of the Pohjanmaa Belt.
H. Mäkitie, P. Sipilä, H. Kujala, A. Lindberg, A. Kotilainen   +4 more
doaj   +1 more source

Use of LiDAR to derive a new model of glacial hydro‐dynamic events shaping southern Ontario landscapes, Canada

Boreas, Volume 54, Issue 4, Page 590-624, October 2025.
High‐resolution LiDAR data with field validation of inferred southern Ontario ice stream terrains indicate that steady‐state ice streaming is difficult to reconcile with our observations. Rather, these new observations show strong evidence of significant fluvial scouring across the area in which meltwater sheet flow overtopped the landscape.
David R. Sharpe, Chris C. Smart
wiley   +1 more source

Using a titanium-in-quartz geothermometer for crystallization temperature estimation of the Palaeoproterozoic Suursaari quartz porphyry [PDF]

Estonian Journal of Earth Sciences, 2012
The Suursaari volcanic sequence represents volcanic activity related to Wiborg Batholith rapakivi intrusions in the southern part of the Fennoscandian Shield. The estimated pressure conditions for batholith granitic rocks are 1–5 kbar and crystallization
Kairi Ehrlich, Evelin Verš, Juho Kirs, Alvar Soesoo   +3 more
doaj   +1 more source

CH4‐He‐H2‐Rich Fluids Associated With the Intrusive Rocks of the Mid‐Continent Rift System in Minnesota (USA)

Geochemistry, Geophysics, Geosystems, Volume 26, Issue 9, September 2025.
Abstract Several studies have shown that H2 and CH4 emissions are recorded within Precambrian areas, where the origin of gases has yet to be determined. The Mid‐Continent Rift (MCR) is an aborted rift aged from 1.1 Ga and composed of volcanic and (ultra)‐mafic rocks.
V. Combaudon, O. Sissmann, J. Guélard, S. Noirez, H. Derluyn, E. Deville   +5 more
wiley   +1 more source

Lithosphere-asthenosphere system in shield areas of North America and Europe

Annals of Geophysics, 1997
In previous papers surface dispersion data have been combined with the results of deep seismic refraction data to derive a regionalization of the lithosphere-asthenosphere system and to investigate the presence of significant heterogeneity down to depths
P. Pierri, V. Del Gaudio, G. Calcagnile
doaj   +1 more source

From Hydrocarbon to CO2 Storage: Unveiling the Potential of the Miocene Lille John Member in the Danish North Sea

Basin Research, Volume 37, Issue 5, September–October 2025.
Depositional evolution of the upper Miocene complex. ABSTRACT To achieve net‐zero carbon emissions by 2050, gigatonnes of CO2 must be captured and stored in the subsurface. Screening and exploration of prospective storage sites have thus gained momentum in recent years.
Zeenat Maniar, Florian Smit, Erik Skovbjerg Rasmussen, Kresten Anderskouv, Kenneth Bredesen, Lars Nielsen   +5 more
wiley   +1 more source

New evidence of the Vuoksi River origin by geodynamic cataclysm [PDF]

Bulletin of the Geological Society of Finland, 2018
The territory of investigations is located in the SE periphery of the Fennoscandian Shield. It served as an arena of periodic significant restructuring of the hydrographic network associated with the filling and discharge of large late-glacial and ...
D.A. Subetto, S.V. Shvarev, A.A. Nikonov, N.E. Zaretskaya, A.V. Poleshchuk, M.S. Potakhin   +5 more
doaj   +1 more source

Palaeoproterozoic magnesite: lithological and isotopic evidence for playa/sabkha environments [PDF]

, 2001
Magnesite forms a series of 1- to 15-m-thick beds within the approximate to2.0 Ga (Palaeoproterozoic) Tulomozerskaya Formation, NW Fennoscandian Shield, Russia.
Aharon P., Aksenov E.M., Al-Aasm I.S., Baker A.J., Botz R.W., Braithwaite C.J.R., Braithwaite C.J.R., Coshell L., Curtis R., Fairchild I.J., Fallick A.E., Hardie L.A., Hudson J.D., Joshi M.N., Karhu J.A., Kralik M., Kretz R., Lambert I.B., Last W.M., McCrea J.M., Melezhik V.A., Misra R.C., Muller G., Perry E.C., Pukhtel' I.S., Renaut R.W., Rosen M.P., Rosen M.P., Rubin D.M., Schidlowski M., Schroll E., Shearman D.J., Southgate P.N., Tucker M.E., Valdiya K.S., Veizer J., Veizer J., Veizer J., Von der Borch C.C., Walter M.R., Yudovich Ya. E.   +40 more
core   +1 more source