Complex sentence: The island, originated by the lifting of a submarine pluton, has a slightly elliptic shape, and is wholly mountainous, with several rock ledges rising steeply from the sea, and consists almost entirely of granodiorite with large crystals of orthoclase.
Split into simpler sentences: The island, formed by the lifting of a submarine pluton, has a slightly elliptic shape, and is wholly mountainous, with several rock ledges rising steeply from the sea. It consists almost entirely of granodiorite with large crystals of orthoclase.