How could this pyramidal peak have been formed in Antarctica? Little is known about it as far as I know but what is known is that its miles away from any existing plate boundary and its shape is also highly atypical, hence I present the above question.
The question bases on two sub-questions really:
A) How did it form so far away from a plate boundary? B) How did it form in this unusual shape?
Such forms tend to be created by glacial activity, which, ahem, the ice-covered continent is known for. Much discussion of this in the related question in Skeptics: Are there three pyramids in Antarctica?
Here's the generic answer in Wikipedia:
A pyramidal peak, sometimes in its most extreme form called a glacial horn, is an angular, sharply pointed mountain peak which results from the cirque erosion due to multiple glaciers diverging from a central point. It may be an example of a nunatak.
Here's a diagram of the formation process posted on Ace Geography:
Not knowing the specifics of the featured peak, as I understand it there are two general mechanisms of glacial erosion that apply:
Assume we begin with some sort of mounded terrain, or a relatively small protrusion on a larger continental surface like Antarctica. In a very cold environment, precipitation will fall as snow, mound up, and turn into ice. Generally, more ice will form on whatever side of the mound that is sheltered from sunlight (north slopes in the northern hemisphere, south slopes in the southern. Eventually the ice will move under its own weight, abrading the surface as it goes in a manner that will tend to exaggerate the original geometry of the mound. If the mound starts with or develops a slight dip in the slope, ice flowing off the back and side walls will dig a cirque or bowl. Depending on the starting conditions, your mound may develop several cirques; as ice grinds away at the lower elevations, you may wind up with a central, relatively slender peak with several ridges and valleys.
A second mechanism is having a glacier coming down a broader slope and cutting through an existing ridge. (Your ridgeline may begin with a triangular cross-section, or may have developed one from the glacial processes mentioned above.) At some point, ice from a higher elevation will flow across or through your ridgeline (just as a river would), eroding a gorge through the ridge.
Inevitably, given enough material to work from, and even with a relatively smooth starting surface, the erosive power of ice will give you steep slopes and some pyramidal structures.
That mountain is mount Evans (3,950 m), located in the Sentinel Range in inner Antarctica (S 78.30698°, W 85.91698°), the highest mountain range in the continent.
(Map courtesy of @KeithMcClary see comments)
In general, geologic features become smoother by erosion (by water, glaciers or wind). These peaks are so high that there were never covered by glaciers and the area is so cold that liquid water almost doesn't exist. Therefore, there is no erosion by water (or freeze thaw cicles), neither the wind, because of the lack of dust/sand particles (the wind doesn't erode by itself, what do erode are the particle it carries). Consequently, those mountains are so sharp due to the lack of erosion. Take for example any rock: If you break it into pieces, those pieces will have sharp edges, with no erosion those sharp edges will persist. Similarly, at a larger scale, sharp ridges and edges on mountains can persist and withstand the pass of time.
This is me on mount Tyree camp one, during The Omega Foundation mapping expedition of 2005, mount Evans is in the background
