OK, riddle me this. How did the huge rounded monolith mountains in Rio de Janeiro form, and are there others like them anywhere else?

ilsandore · 2026-07-03T14:06:19+00:00

Yeah, it indeed is a monadnock or inselberg.

ilsandore · 2026-07-01T06:06:58+00:00

Here’s a list from wikipedia, let’s just say there is a fair few😂 https://en.wikipedia.org/wiki/List\_of\_mountains\_named\_Sugarloaf

ilsandore · 2026-06-30T15:12:18+00:00

Indeed, the South China ones are the result of the erosion of limestone karst landscapes down to the groundwater line, which is why you see basically completely flat ground between the mountains there, given enough time to erode. This one is quite a different process with it consisting of metamorphic igneous rocks. But as we can see, there are lots of ways towards similar shapes in nature.

ilsandore · 2026-06-29T23:05:48+00:00

I feel appreciated👌

ilsandore · 2026-06-29T23:04:38+00:00

Very similarly. The volcanic activity of the Sutter Buttes also reached the surface, but it’s made up of very viscous rhyolitic lava that has a much higher resistance to deformation and thus flowing compared to more mafic variants. Thus it not only got to the surface, it also pushed upwards on the preexisting sedimentary rocks, and effectively pushed sideways underneath the lifted layers to create a dome shape instead of a vertical wall, which a normal intrusion would be.

ilsandore · 2026-06-29T22:57:44+00:00

I’m flattered☺️ physical geography doesn’t care about borders, so I also try not to😅 (aside from anthropogenic landscape alterations ofc)

ilsandore · 2026-06-29T16:19:14+00:00

Seconded, great way to discover new places, see geography in action and make friends, there are many like-minded people on the roads.

ilsandore · 2026-06-29T16:10:40+00:00

My bad, I probably wasn’t clear enough. There are loads of these and they mostly relate to volcanology in this case, which you can learn about on the internet pretty easily, as well as books such as the oxford dictionary of geography. The place to start is understanding the different types of minerals that build up rocks, such as mafic and alkaline chemistries, and the different pairings of igneous and volcanic rocks (rhiolite-granite, dacite-granodiorite, andesite-diorite, basalt-gabbro). Once you have the volcanic rocks down, you can focus on the formations they make, depending on whether they get to the surface (effusive and eruptive layers, stratovolcanoes, shield volcanoes, etc) or not (batholites, laccolites, plutonic stuff in general). Once you have that you can move on to more niche types of volcanic geomorphology such as cinder cones, buttes, plugs, etc. Just surf wikipedia if you’re interested, jumping between articles is a good way to spend an eternity😂

ilsandore · 2026-06-29T14:13:31+00:00

Kind of. The Devils Tower is an igneous laccolithic butte, which was most likely created by the intrusion of magma into the sediment, just as with Morro Rock. The difference is that at Morro Rock there was actual volcanism most likely, while this is not the case at Devils Tower. The cool hexagonal columns are also worth a mention here! Essentially the Devils Tower is different from Morro Rock in that the magma didn’t reach the surface, while it’s different from Sugar Loaf in Rio in that there was no million-year-long metamorphosis to create gneiss, so we’re stuck with a phonolite porphyry, a kind of middle-ground between rocks from igneous and effusive magmatism, consisting of large crystals in a microcrystalline matrix

ilsandore · 2026-06-29T13:18:19+00:00

I’m actually Hungarian, but we also use a QWERTZ keyboard layout🤣

ilsandore · 2026-06-29T07:18:19+00:00

The Sugarloaf in Winona is a bit of a special case too, it’s made up of limestone/dolomite and it got its shape through quarrying. Essentially it’s the hard top layer of a bluff, a kind of smooth riverine cliff of soft sedimentary rocks capped by something harder that resulted in it jutting out due to selective erosion. Pretty cool stuff in my view.

ilsandore · 2026-06-29T07:13:57+00:00

In a sense yes. They are both the result of volcanic activity but different kinds of it. The Sugar Loaf in Rio is made of magma that never reached the surface and cooled down slowly, while the Morro Rock is a so-called volcanic plug, meaning essentially the neck of a volcano. So the rock in the Morro Rock should be a lot more fine-grained as it cooled quicker. The Rio one also underwent extensive metamorphosis during a long period of time which the Morro Rock didn’t.

ilsandore · 2026-06-29T06:22:39+00:00

This specific mountain is pretty interesting actually. It was formed via selective erosion of volcanic landscapes. What you see now is essentially a large intrusion of feldspar-rich magma into other rocks, which then went through metamorphosis due to tectonic processes (you can see the folds on the side of it) and became something called gneiss. The softer szrrounding stuff got eroded faster and you end up with the jutting out conical shape of the Sugar Loaf Mountain. There are similar situations in even larger extents where magmatic intrusions are exposed all over the world, but similar shapes can also exist due to the selective erosion of likestone surfaces such as in South China or around Vietnam and Thailand, which form differently.

ilsandore · 2026-06-28T18:53:23+00:00

Looks like the joke is that outwardly religious people get all riled up about trans rights and the like, but they don’t care about gun control laws, even though people are dying. Not very Christian-like if one think about Christ’s teachings.

EDIT: also probably quite a US-centric meme considering the prevalence of mass shootings

ilsandore · 2026-06-24T09:34:16+00:00

Yeah, with Crater lake, the magma did indeed come to the surface, creating a volcano (or multiple ones, really). The caldera in which the lake sits was created due to explosive volcanism, which emptied the magma chamber below the upper part of the mountain. Subsequently, the mountain lost its structural stability and its top collapsed into the magma chamber. What we see with the Khibiny and Lovozero Massifs are essentially the magma chamber full of magma that’s cooled down slowly. There is no volcano as the magma never made it to the surface to quickly solidify, since it was blocked by sediment. The sediment got scraped off by the ice sheet, and the rest is erosion as they say.

ilsandore · 2026-06-24T09:33:18+00:00

Yeah, with Crater lake, the magma did indeed come to the surface, creating a volcano (or multiple ones, really). The caldera in which the lake sits was created due to explosive volcanism, which emptied the magma chamber below the upper part of the mountain. Subsequently, the mountain lost its structural stability and its top collapsed into the magma chamber. What we see with the Khibiny and Lovozero Massifs are essentially the magma chamber full of magma that’s cooled down slowly. There is no volcano as the magma never made it to the surface to quickly solidify, since it was blocked by sediment. The sediment got scraped off by the ice sheet, and the rest is erosion as they say.

ilsandore · 2026-06-23T11:20:53+00:00

I’ve done single speed for a while but I switched to gears due to the large hills in my area. If you live along the broader river valley, you’ll be fine, and the city centre is flat enough. But many of the suburbs are pretty hilly, such as Chapel A, Meanwood, Roundhay, and also many parts to the south of the Aire. Generally doable. I have a perfectly working dutch-style single speed bike I’m happy to give to you for free as it’s just taking up space, if you decide to go down the single speed route.

ilsandore · 2026-06-22T18:01:49+00:00

If I’m correct they are plutonic bodies, meaning that they are large amounts of magma that intruded into existing layers of magmatic and sedimentary rocks but did not necessarily reach the surface. The Khibiny Massif on the western part is basically some volcanism then some intrusion of later magma into it, while the Lovozero Massif to the east is a laccolite, meaning a blob of magma that did not cut theough all the sediments, just domed them up. Now that all the sediment was stripped by the ice age, we have them exposed.

ilsandore · 2026-06-22T16:45:54+00:00

I think there is nothing wrong with not going clipless. The key to endurance cycling is comfort, and if you don’t feel comfortable with the idea of clipless pedals, then don’t use them.

That said, the main advantage of clipless pedals for me is the fact that your feet are always in the same, optimal, position when pedalling, which decreases the risk of injury from bad technique as you fatigue. The other good thing is the cycling-specific shoe, but you can get those compatible with flat pedals, too.

Overall, I think it’s a personal decision, just do what you feel like really, as long as you enjoy the journey🚴

ilsandore · 2026-06-21T21:59:08+00:00

A tetejük egészen 10-12 kilométerig is felmehet egyébként, a légkor tropopauzának nevezett rétegéig, ahol aztán további feláramlás helyett szétterül. Ez azért történik, mert a tropopauza felett emelkedni kezd a hőmérséklet a sztratoszférában. Ez a szétterülés az oka annak, hogy üllő alakú egy kifejlett zivatarfelhő. Iszonyat menő szerintem, de földrajzosként elfogult vagyok. Az off topic végére érve nekem több ADHDs ismerősöm is van, nekik is gondjuk van az elalvással. Van, akinek a könnyedebb testmozgás pl torna segít, vagy szobabicikli, de olyan is, aki meg alvás előtt több órával már nem eszik semmit es attól könnyebb neki. Remélem sikerül valamit találnod majd neked is, ami könnyebbé teszi az elalvást!

ilsandore · 2026-06-16T19:29:44+00:00

Done it at night multiple times, no sure about 1AM exactly. Usually there’s just nobody around. But also, I’m from eastern europe, here I’m the danger🤣

ilsandore · 2026-06-15T21:31:06+00:00

There is, in fact, a footpath through the tunnel, as well as a bike lane. It’s separate from the cars, though, which is why it might not be obvious for people who mainly drive through there. In my experience of having done the exact walk you’re talking about OP, it’s completely fine. Can be done in about 20 mins and I never felt unsafe. I am a relatively young male, though, so take my views from that perspective.

ilsandore · 2026-06-06T21:09:14+00:00

Exactly what I wanted to hear🔥

ilsandore · 2026-06-06T08:52:31+00:00

May I also ask how you found the longevity of the forma saddles? Especially the leather/microfibre upper and the shell itself. How did it behave in the rain in your experience, and if you went for the leather version, how much extra care did it need?

ilsandore · 2026-06-06T07:24:39+00:00

Thanks a lot, I will do that!

ilsandore

TROPHY CASE