Mountains are a famous feature of Middle-earth, with numerous rising peaks soaring above their neighbors. Caradhras in the Misty Mountains which stood high above the underground city of Moria; Mount Gundabad, birthplace of the dwarves and now a place occupied by legions of goblins; and other such mountains gained fame as set pieces for the stories of Tolkien’s world.
Three mountains stand out, however, as being lone peaks that seem to rise above the surrounding landscape, like great monuments that stand out in stark contrast to the lowlands at their feet. These are Meneltarma, the Sacred Mountain of Numenor; Orodruin which dominated the Plateau of Gorgoroth and was better known by the name of Mount Doom; and of course the Lonely Mountain, also known as Erebor, beneath which the dwarves built the Kingdom Under the Mountain, and was for a time occupied by the dragon Smaug.
So what causes mountains like this? These tall lonely monuments that stand above the crust of the earth. Well the answer is…they don’t really. Simply by description we can assume that all three of these mountains are likely volcanoes, though of them only Mt. Doom is regularly active. So we’re going to go through these one by one to try and make a little sense of them. Unfortunately, as this post is already quite long, I’ve had to break it up a bit. This post will focus on the great sea-going nation of Numenor and their Sacred Mountain.
To those of you most familiar with the Lord of the Rings and the Hobbit, the island of Numenor is something only mentioned in passing and likely escaped notice. It is, in short terms, Tolkien’s Atlantis. Though once noble and blessed, the people of Numenor were corrupted by Sauron’s influence and were spurred on to declare war upon the Valar. While some number of the faithful escaped, the great creator of all things, Eru Iluvatar, came down and sank Numenor beneath the waves. I’m not going to attempt to explain the destruction of Numenor geologically as it was explicitly divine intervention, but the island itself was made along with the rest of Arda, and that is something we can explore.
The island itself is technically named Elenna, but the name of the realm upon it was much better known. Although it created a vast maritime empire, the island of Elenna was roughly the same size as Sumatra according to Tolkien’s notes as well as the calculations done in the Atlas of Middle-earth (and corroborated by my own). So while it was certainly large it wasn’t quite a lost continent. The most notable feature of the island itself was Meneltarma, the Sacred Mountain. It was a massive mountain that rose high from the center of the five-pointed island. This gives Elenna a character and geography not unlike numerous tropical islands such as Kauai and Gran Canaria, with the island being formed a volcano created by an oceanic hotspot.
In short terms, in an area where a plume of hot magma from the mantle pushes through the crust, a volcanic hotspot forms which can lead to the creation of tall but broad “Shield” volcanoes. Multiple and frequent eruptions form the shield volcanoes (Which are non-explosive and produce copious lava) can create large islands, but these volcanoes become extinct when the tectonic plate moves the volcano away form the hotspot, leaving it to erode as new volcanoes rise up where it once was. In our modern tectonic ally active world this can create island chains such as the Hawaiian Islands and the Canaries.
Elenna’s five-pointed geology could indicate a past series of eruptions from Meneltarma (or at least it was created to idnicate such). However, this leads to an interesting issue. Meneltarma is never noted as being volcanically active, and if it was indeed a shield volcano then the people of Numenor would have noticed flows of lava running from their sacred mountain fairly often. The implication, of course, being that there had been some tectonic movement and the hotspot had moved. This is supported by the existence of a second smaller mountain on Elenna, Forontil.
Perhaps the island had moved from the hotspot entirely, and a new mountain would someday rise beside Numenor. Whether the sinking of Elenna put a stop to that, who can say? The Legends of Tolkien’s world say that some still believe that the peak of Meneltarma rises form the water where Numenor once dominated. Perhaps it is not the sacred mountain that explorers would find out there, but a newer younger mountain of hardened lava rising from the waves.