The Tablelands, found between the towns of Trout River and Woody Point in south west of Gros Morne National Park, look more like a barren desert than traditional Newfoundland. This is due to the ultramafic rock – peridotite – which makes up the Tablelands. It is thought to originate in the Earth's mantle and was forced up from the depths during a plate collision several hundred million years ago. Peridotite lacks the usual nutrients required to sustain most plant life, hence its barren appearance. The rock is very low in calcium, very high in magnesium, and has toxic amounts of heavy metals. Peridotite is also high in iron, which accounts for its brownish colour (rusted colour). Underneath this weathered zone, the rock is really a dark green colour.