Animal and even plant horror are familiar categories: you can find entries for horror films featuring mammals, reptiles, amphibians, insects, birds, and plants, for instance, on Wikipedia (check out the List of Natural Horror Films). So far, however, you’ll be hard-pressed to find anything about geological horror. So where are the horror films about rocks and minerals? (That’s not a rhetorical question: if you know of any, please let me know!) My main purpose in this post is to suggest a candidate for the horror genre that features a boulder. The film is 127 Hours (2010), directed by Danny Boyle of 28 Days Later (2002) fame. It depicts the (real) ordeal of Aron Ralston (James Franco), whose arm becomes trapped by a boulder as he’s climbing in Blue John Canyon in Utah: as the title suggests, he spent 127 hours in the canyon before freeing himself by amputating his arm and stumbling across the desert to find help.
There are, of course, a multitude of films about natural disasters (tsunamis, volcanoes, earthquakes, avalanches etc.), but these films tend not to be horror films (they’re routinely classified as action)—and natural disasters are typically not exploited in the horror genre—except sometimes as plot devices to trap characters in places where they have to face other monsters. 127 Hours is a horror film. The film is not wholly horror; indeed, it swerves away from horror near the end. But in and by that swerve it demonstrates what actually makes a horror film (and what doesn’t).