The figure symbolically  presents a section through both oceanic crust and uppermost mantle, a so-called ophiolite sequence. Most of these rocks are found at Leka, which makes the area so special. Sedimentary rocks are found on Skeisnesset (locality 4), pillow lava is be found just north of the island Leka, layered peridotite and rocks from the mantle, and the boundary between, the Moho, can be studied at locality 6. Gabbro is found for example southwest on Leka.