#Variscan
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geosociety.bsky.social
How did Variscan granites form in NW Iberia?

This new #GSABulletin study identifies two distinct magmatic pulses driven by crustal melting, fertility loss, and later lithospheric delamination.

Read the article: geosociety.co/Gonzalez-Menendez_et_al
Image: Figure 16 from the paper.
January 21, 2026 at 6:01 PM
palaeokatie.bsky.social
rock and a hard place wait for me
between the devil and the deep blue sea
everything I ever did right or wrong
hid out of sight where I belong

happy winter solstice (and the promise of longer rock hunting days) x
Picture looking south on the Berwickshire coast showing a section of Carboniferous cliffs. Rocks are sandstones belonging to the Fell Sandstone Formation. They are composed of fluvial (river) sandstones with interbedded mudstones, deposited in a floodplain setting. The rocks are now dipping almost vertically due to tectonic activity associated with the variscan orogeny (mountain building event).
December 21, 2025 at 10:53 PM
geologica-acta.bsky.social
New published manuscript: Evolution of microstructure and texture in a small-scale hightemperature #marble shear zone from the Ossa-Morena Zone (Iberian #Variscan Belt) by M. Machek et al.
Link: revistes.ub.edu/index.php/GE...
A 33cm geological hammer for scale.
November 13, 2025 at 12:38 PM
gongudottir.bsky.social
NOW I've become wiser & therefore I want to make sure you don't 'die ignorant' either

Oslo lies on a rift valley created by volcanism ( en.wikipedia.org/wiki/Oslo_Gr... )

This is also the reason for earthquakes - here's a report www.jordskjelv.no/meldinger/li... with seismic diagrams, etc.,

2/4
The Oslo Graben or Oslo Rift is a graben formed during a geologic rifting event in Permian time, the last phase of the Variscan orogeny.[1] The main graben forming period began in the late Carboniferous, which culminated with rift formation and volcanism, with associated rhomb porphyry lava flows. This activity was followed by uplifting, and ended with intrusions about 65 million years after the onset of the formation. It is located in the area around the Norwegian capital Oslo. The lava production was high when the rhomb porphyry lavas were deposited. The lavas reflect a period of abundant earthquake-related movements, when tectonic forces tore the crust apart. In the Vestfold district, one lava flow was deposited on average every 250,000 years, resulting in a 3000-metre thick sequence of mainly volcanic material. In the Oslo area, lavas were deposited on average every 800,000 years. Only a few plant remains have been found between these lavas. The bedrock in this area, roughly from Skien to Oslo and Mjøsa, results in soil rich in nutrients important for plant growth. Since the Permian, erosion has removed the volcanic peaks and indeed most of the lava layer and laid bare the magma chambers and volcanic pipes deep below, allowing scientist a rare view of what goes on beneath a rift valley. This made it popular among early students of geology, among other Christian Leopold von Buch (1810). Several of the old magma plumes are now quarried, the rich black larvikite (named from Larvik, a town south of Oslo) being one. The Särna alkaline complex in western Sweden, also of Late Carboniferous age, is thought to be related to the Oslo Graben as it is aligned to it.[2] See also Kattsund-Koster dyke swarm – Large geological structure in Norway and Sweden
October 27, 2025 at 9:03 AM
ipaleopan.bsky.social
Brachiopods of the Variscan orogen link.springer.com/chapter/10.1...
#geologia #paleontologia #paleontology #paleobiologia #paleobiology
Rycina: The authors of the chapter with particularly large Devonian and Carboniferous brachiopods: (a) Bernard Mottequin (Royal Institute of Natural Sciences, Brussels, Belgium) showing two Lower Carboniferous brachiopods, a spiriferide and a productide (b) Adam T. Halamski (Institute of Paleobiology, Warsaw, Poland) showing a Gigantoproductus giganteus (the largest known brachiopod – Lower Carboniferous) in an outcrop in the Pennine Mountains (c) Ulrich Jansen (Senckenberg, Frankfurt am Main, Germany) showing a Stringodiscus giganteus (Middle Devonian).
October 13, 2025 at 8:47 PM
craiubcterra.bsky.social
#geoubcsic U-Pb-age from undeformed granite pebbles in Carboniferous Culm conglomerates: new geochronological constrains on the Variscan events in the Pyrenees. Casas, JM; González-Esvertit, E; ... LITHOS 216 [2025] doi.org/10.1016/j.lithos.2025.108227
October 13, 2025 at 11:28 AM
🧪⚒️I just posted an episode on the orogenies that shaped central Europe: the Cadomian and the Variscan. The former took place on the northern margin of Gondwana, rifting north later to dock to Europe. The latter marked the final assembly of Pangea. It's complex, but I hope you enjoy it! #geology
Map of Europe showing the main geological units as defined by their structural origin and presumed terrane provenance. As the map shows, practically all of central and southern Europe (shaded grey) was derived from Gondwana. These terranes contain Cadmonian and Lower Paleozoic basement rocks. The map also shows the main suture zones. A Alps, AM Armorican massif, B Balkans, BM Bohemian massif, BV Brunovistulia, CIZ Central Iberia Zone, D Dinarides, DO Dobrogea, EC Eastern Carpathians, H Hellenides, IM Iberian massif, IST Istanbul terrane, KB Kirsehir block, MC massif Central, MGCR Mid-German Crystalline Rise, MM Menderes massif, MP Malopolska block, MU Moldanubian unit, OMZ Ossa-Morena Zone, P Pyrenees, R Rhodope, S Schwarzwald, SC Scythian platform, SM Serbo-Macedonian massif, SPZ South Portuguese Zone, SX Saxothuringian unit, TBU Teplá–Barrandian unit, V Vosges. Sen, F. (2021), International Geology Review 64, 2416 There is a debate as to how far the Cadomian terranes, specifically the major Teplá–Barrandian unit of the central Bohemian Massif, traveled away from Gondwana before they accreted to Baltica, eventually to become part of Europe. These figures illustrate contrasting models that have been proposed. (a) In this model there is a large separation between the Teplá–Barrandian unit and Gondwana, and the unit forms a completely detached microplate called Perunica (P). (b)-(d) In these models, there is little separation, and the Teplá–Barrandian unit remains part of the hyper-extended Gondwana shelf. Žák, J et al. (2018), International Geology Review 60, 319 A paleogeographic model showing the break-up of the former northern Gondwanan Cadomian active margin in the late Cambrian and early Ordovician, opening of the Rheic Ocean, transition to an early Paleozoic passive margin, and, finally, the Laurussia-Gondwana collision to form the Variscan orogenic belt. The terranes discussed in the podcast form parts of Avalonia, the Saxothuringian and Ossa-Morena Zones, the Variscan Autochthon, and the Mid-Variscan Allochthon. The Saxothuringian Zone now makes up the northwestern part of the Bohemian Massif. The Ossa-Morena Zone now forms part of the Iberian Massif in Spain and Portugal. The Variscan Autochthon comprises geological units now mainly exposed in southern Europe. The Mid-Variscan Allochthon includes the Teplá-Barrandian and Moldanubian units of the present-day Bohemian Massif. Catalán, J.R et al. (2021), Earth-Science Reviews 220, 103700 Geological map of the present-day Bohemian Massif. The geological structure is complex, largely as a result of the Cadmonian and Variscan orogenies. The map covers a region stretching from southern Poland in the north to northern Austria in the south. It reveals a section across the Variscan orogen from the outer foreland basins (Rhenohercynian) through low-grade Cadomian basement terranes (Saxothuringian and Teplá-Barrandian) to the exhumed high-grade orogenic core (Moldanubian). Adapted from the Geological map of the Czech Republic 1:5,000,000 published by the Czech Geological Survey, Prague, 2007
October 6, 2025 at 2:02 PM
etiennemedard.bsky.social
Yes, that type of mantle (likely mica-bearing) occurs everywhere that has been "dirtied" by a subduction, so you can have them postcollisional (e.g., Variscan of central France, Turkey and Iran nowadays), or even intraplate
October 3, 2025 at 11:46 AM
craiubcterra.bsky.social
#geoubcsic Discussion on 'Oroclinal arcs of the Variscan Belt: a consequence of transpression during the consolidation of Pangaea', by Martinez Catalan et al . 2024 ( JGS, 181, jgs2024-007). Casas, JM; Guimerà, J; ... JOURNAL OF THE GEOLOGICAL SOCIETY 182:6 [2025] doi.org/10.1144/jgs2024-247
September 29, 2025 at 11:40 AM
aliball.bsky.social
I love the ruggedness of Sardinia.The largest part consists of a Variscan (Paleozoic) basement, made of metamorphic rocks and a Permo-Carboniferous granitic batholith, formed during the Variscan orogeny around 340 to 280 million years ago. #Sardinia 🇮🇹
Sardinia
September 17, 2025 at 7:44 AM
asxmktsensitive.bsky.social
Variscan Mines ( #VAR ) has released " Excellent Historic Surface Drilling Results on New Licences " on Tue 16 Sep at 08:20 AEST #today #government #Commodity #trading #Mining
Variscan Mines share price
Variscan Mines (ASX:VAR) is an asset listed on the ASX, and part of the Materials sector. Grafa’s asset page shows Variscan Mines’s share price, chart, trading
grafa.com
September 15, 2025 at 10:25 PM
dmontanes.bsky.social
Variscan da un nuevo paso para reactivar la extracción de zinc en Udías en 2027 | El Diario Montañés leer.eldiariomontanes.es/q...
Variscan da un nuevo paso para reactivar la extracción de zinc en Udías en 2027 | El Diario Montañés
Antes de lograr el permiso en todo el complejo, la compañía puede ya realizar sondeos y labores previas en la antigua mina de Novales tras aprobar el plan de restauración
leer.eldiariomontanes.es
September 6, 2025 at 4:00 PM
planetaryecologist.mastodon.social.ap.brid.gy
Variscan chain (Paleogeography 🦕)

The Variscan orogeny, Hercynian orogeny or Variscan chain was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica and Gondwana to form the supercontinent of Pangaea. It remains visible today as a series of […]
Original post on mastodon.social
mastodon.social
August 27, 2025 at 7:15 AM
nebogeo.post.lurk.org.ap.brid.gy
Variscan coast synthesis (chalcopyrite transistor)

Feeding vactrol (led -> light dependent resistor) controlled square wave fm through a chalcopyrite crystal acting as a 'transistor', fossicked from Carharrack Mine, Cornwall, interacting with a volca modular used for percussion.

This […]
Original post on post.lurk.org
post.lurk.org
August 10, 2025 at 8:43 AM
pimientuco.bsky.social
Great Variscan (and more) meeting in Toulouse #GeoTolosa25
June 26, 2025 at 10:09 AM
geologiaoviedo.bsky.social
Javier Sanz y Silvia Blanco han participado en el 20th International congres son Carboniferous and Permian Variscan Meeting que se celebra en la Universidad de Tolouse (Francia).
Silvia Blanco ha sido designada como miembro con voto de la Subcommision on Carboniferous Stratigraphy. ¡Enhorabuena!
June 26, 2025 at 8:04 AM
lithospheric.jorgegines.com
#FridayFold!
Punta das Cabras, Galicia (Western Asturian-Leonese Zone of the Variscan orogen), where one can find many striking examples of high-strain folding within shear zones.
Recumbent to sheath fold in quartzites & micaschists in the basal part of the Cándana Gp. (Lower Cambrian)
#geology ⚒️🧪
A photo of a fold, recumbent to sheath. A coin for scale.
June 20, 2025 at 3:16 PM
doktrock.bsky.social
Beautiful porphyritic granodiorite, part of the Variscan basement, on the Costa Brava, Mediterranean Spain. ⚒️🧪 #geology
Rocky coastline with structures in the background Igneous rock with matrix of smaller crystals containing larger feldspar crystals. 1 Euro coin for scale Closer view of porphyritic igneous rock. 1 Euro coin for scale Plaque describing the local geology focusing on large crystals of feldspar
June 15, 2025 at 9:30 PM
palaeoclimate.bsky.social
Yesterday was our first look at the upper Carboniferous Coal Measures, and subsequent Variscan deformation.

Didn’t spot any lepidodendrons this time but saw lots of calamities (horsetails).
Thrusted folds at Broadhaven are always impressive!
Chatting about the plunging anticline we’re about to see at the Skeekstone, from the picturesque Den’s Door. Calamites (ancient horsetails) fossils in the dark fine grained sediment of the lower coal measures. Students sketching the always impressive thrusted fold at Den’s Door (Broadhaven)
May 6, 2025 at 7:06 AM
robsongfreire.bsky.social
Extração de ouro em Portugal...
Na época romana, o ouro foi extraído da Península Ibérica em 2 regiões geologicamente diferentes. Ambas são partes do cinturão Variscan, um cinturão de montanha colisório que atravessou a Europa central e, antes da abertura do Oceano Atlântico, seguia nos Apalaches
May 1, 2025 at 9:48 AM
gbifmorpho.bsky.social
New #checklist dataset in @gbif.org: New aquatic vertebrate and ichnological remains from the Upper Carboniferous of Decazeville (Aveyron, France): implications for the paleofauna of the French Variscan bas… (4 species occurrences) https://www.gbif.org/dataset/b0127c19-b6f7-4da4-9c25-a587ee0a58be
April 30, 2025 at 3:30 PM
cottonjenny.bsky.social
New aquatic vertebrate and ichnological remains from the Upper Carboniferous of Decazeville (Aveyron, France): implications for the paleofauna of the French Variscan basins - Scientific publications of the National Museum of Natural History, Paris sciencepress.mnhn.fr/fr/periodiqu...
New aquatic vertebrate and ichnological remains from the Upper Carboniferous of Decazeville (Aveyron, France): implications for the paleofauna of the French Variscan basins
Le bassin de Decazeville (Aveyron, France) est un bassin intra-varisque du Carbonifère supérieur de la partie méridionale du Massif central. Sa géologie et son contenu paléontologique (faune et flore)...
sciencepress.mnhn.fr
April 16, 2025 at 4:16 PM
asxmktsensitive.bsky.social
Variscan Mines ( #VAR ) has released " New Licences Expand Novales-Udias Project Area " on Mon 14 Apr at 08:24 AEST #Russia #government #Mining #Australia #media
Variscan Mines share price
Variscan Mines (ASX:VAR) is an asset listed on the ASX, and part of the Materials sector. Grafa’s asset page shows Variscan Mines’s share price, chart, trading
grafa.com
April 13, 2025 at 10:29 PM
stompdearth.bsky.social
Is the Variscan the most extensive fold belt of its kind?
April 11, 2025 at 11:34 AM
gizmotron.bsky.social
Lovely! We have similar chevron folds in Cornwall from the Variscan near Crackington Haven.
Tight chevron folds in rocks at Crackington Haven.
April 11, 2025 at 9:24 AM