The geology of the Grand Teton area consists of some of the oldest rocks and one of the youngest mountain ranges in North America. The Teton Range, partly located in Grand Teton National Park, started to grow some 9 million years ago. An older feature, Jackson Hole, is a basin that sits aside the range. The 2.5 billion year old metamorphic rocks that make up the east face of the Tetons are marine in origin and include some volcanic deposits. These same rocks are today buried deep inside Jackson Hole. Paleozoic rocks were deposited in warm shallow seas while Mesozoic deposition transitioned back and forth from marine to non-marine sediments with the Cretaceous Seaway periodically covering the area late in that era. Precambrian deposition, metamorphism, and intrusion Perhaps 3 billion years ago in Precambrian time, sand, limey ooze, silt and clay were deposited in a marine trough (accurate dating is not possible, due to subsequent partial recrystallization of the resulting rock). Between these layers were volcanic deposits, probably from an island arc. These sediments were later lithified into sandstones, limestones, and various shales. These rocks were 5 to 10 miles (8 to 16 km) below the surface when orogenies (mountain-building episodes) around 2.8 to 2.7 billion years ago intensely folded and metamorphosed them, creating alternating light and dark banded gneiss and schist. Today these rocks dominate the east side of the Teton Range with good examples easily viewable in Death Canyon and other canyons. The green to black serpentine created was used by Native Americans to make bowls. Sometime around 2.5 billion years ago, blobs of magma intruded into the older rock, forming plutons of granitic rock. Extensive exposures of this rock are found in the central part of the range. About 1.3 to 1.4 billion years ago in Late Precambrian, 5 to 200 foot (1.5 to 60 m) thick black diabase dikes intruded as well, forming the prominent vertical dikes seen today on the faces of Mount Moran and Middle Teton (the dike on Mount Moran is ). Some of the large dikes can be seen from the Jenny Lake and String Lake areas. More than 700 million years elapsed between intrusion of the black dikes and deposition of the first Paleozoic sedimentary rocks. The Precambrian rocks were uplifted during this gap in the geologic record known as an unconformity; exposed to erosion they were gradually worn to a