I'm starting a #geology thread with #GlacialErratics I found in my region (Västerbotten, Sweden. Last glaciation: Weichsel, ended ca. 10ky ago).
The first one is a porphyry.
Found in: Umeå (esker)
Probably from: Arvidsjaur/Arjeplog area
Notes: contains magnetite.
New #GlacialErratics from Sweden/Västerbotten:
Fragment of gneiss leucosome with big cordierite crystal.
Found in: Umeå, Klockarbäcken (esker or till)
Probably from: Precambrian basement.
Notes: fresh fragment from a bigger gneiss boulder.
New #GlacialErratics !
Garnet amphibolite with plagioclase.
Found in: Umeå (esker).
Probably from: I've really no idea!
Notes: garnet amphibolite is relatively common in material I found here, but it's usually darker.
#Geology
#GlacialErratics lost siblings reunited?
#mafic rocks (metabasalt?)
Found in: Malå (left); Umeå, esker (right), ca. 170 Km apart.
Notes: they've very similar textures and contain magnetite (darker crystals/veinlets).
#GlacialErratics
#sedimentary sparagmite (arkose/sandstone), probably of ediacaran age.
Found: Umeå (esker)
Probably from: Sorsele/Arjeplog area.
#GlacialErratics
A fragment of feldspar with some rose quartz inclusions.
Found: Sörböle (Umeå), till.
Probably from: Precambrian Svecocarelian basement
Notes: it's my only rose quartz finding so far. #TeamQuartz
#GlacialErratics #Igneousrocks
A fragment of what looks like Revsundsgranite intruded by mafic rock (basalt?).
Found: Umeå, esker.
Probably from: Precambrian basement.
Note: notice the margins. Looks to me like the mafic rock is younger.
When I post rocks from "Umeå, esker", that's how it looks like. It's a esker cut by present days Umeälven river (after @sguSverige maps). It's possible to find fresh material bc of erosion.
New #GlacialErratics
Conglomerate, major clasts looking like shale/schist.
Found in: Sörböle, Umeå (moraine or esker, there's mixed material in that locality)
Probably from: Caledonides, eventually autochtone margin.
Notes: Only found conglomerate sample with such clasts.
Micaschist with staurolite xls.
Found in: Sörböle, Umeå (moraine).
Probably from: Caledonides
#garnet gneiss is this latest #GlacialErratics
Found in: Sörböle, Umeå (moraine)
Probably from: precambrian basement
Notes: much likely it hasn't travelled so long. Garnet paragneiss is common here.
A bigger boulder of #GlacialErratics with amphibolites (tremolite + actinolite?)
Found in: Sörböle, Umeå (moraine)
Probably from: good question.
Notes: this is one-of-a-kind boulder.
#Garnet and tourmaline schorl porphyroblasts in a matrix of quartz and feldspar.
Found in: Sörböle, Umeå (moraine)
Probably from: svecocarelian basement.
Notes: bigger boulders of similar composition, with almost euhedral crystals, are found in this locality.
Fresh hammered granite fragment.
Found in: Umeå, Klockarbäcken (moraine)
Probably from: Svecocarelian basement.
Notes: granites of different colours, xls dimension and compositions are relatively common in till here, almost as gneiss. Often w nice Carlsbad twins.
Boulder (ca. 30 cm) with what looks like magma mingling.
Found in: Umeå, Klockarbäcken (moraine)
Probably from: Svecocarelian bedrock. A lot of igneous rock are found in area between SW Norrbotten and N Västerbotten.
Notes: it decorates my garden now. One of my favourites.
Greenschist/phyllite.
Found in: Sörböle, Umeå (moraine).
Probably from: Caledonides.
"Ovary stone", very hard nodule, probably lithophysae (cut and wet surface on the left)
Found in: Sörböle, Umeå.
Probably from: precambrian bedrock, Duobblon area.
Notes: Lithophysae have been found in acid volcanic rocks near Sorsele (Vällingträsk).
This pebble is not "probably from", but surely from Sorsele area, bc it's Sorsele granite, sometimes cited as part of the Transscandinavian Igneous Belt.
It's a monzogranite w porphyritic texture and some magnetite, ca 1.7Ga old, travelled ca 270-300 km.
Found in: Umeå (esker).
#volcanic rock with some pumice clasts.
Found in: Umeå (esker)
Probably from: Precambrian bedrock.
Notes: some parts are light greenish fluorescent in SW-UV.
Another #Glacialerratics very likely to be #volcanic : probably a basalt with calcite filled vescicules. The weathered rock surface shows a flow pattern.
Found in: Sörböle, Umeå (moraine)
#geology
New #Glacialerratics : unakite.
Found in: Sörböle, Umeå (moraine or esker).
Probably from: Precambrian bedrock.
Notes: unakite has been found in some locations in our region and is not uncommon in glacial material. Epidote can be massive or in veinlets.
New wednesday #geology post with #Glacialerratics.
This time you got a phyllite.
Found in: Sorböle, Umeå (moraine?)
Probably from: Caledonides.
Notes: the pic isn't that good, but this sample shows nice crenulation.
#Glacialerratics found in Sörböle, Umeå (moraine).
Black, heavy pebbles with magnetite, I suppose mafic igneous rocks.
Mafic or intermediate #Glacialerratics with nice texture of rounded dark minerals.
Found in: Sörböle, Umeå (esker or moraine)
I've discovered that there's a thread about #stonesathome
My #glacialerratics are falling in this category.
This is a hammered bit of milky quartz with some bluish big xls. My guess is cordierite, but it can be wrong.
Unknown origin, found in Sörböle, Umeå (moraine)
#stonesathome : another #Glacialerratics
Small quartz crystals from a small vug in what looked like a granite/granitoid boulder.
Found in: Sörböle, Umeå (moraine).
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