Grand Teton N.P., WYO


While visiting and exploring Yellowstone National Park in 2010, it was an easy trek through the South-Gate of Yellowstone to visit the Grand Teton National Park.

The Official Public Domain Map of The Grand Teton National Park

The Grand Teton National Park protects some of the most stunning mountain scenery in the U.S.A.

Entering the Grand Teton National Park from the south near Jackson Hole, Wyoming.

The Teton Range, the highest mountains in Wyoming, rise abruptly from the Jackson Hole valley floor, their jagged peaks reflected in the valley’s lakes.

The northern end of Jackson Lake, looking south towards Mount Moran on the right, picture taken July of 2010.

The Tetons are one of the youngest mountain ranges in North America. They have been uplifting for less than 10 million years, making them young, compared to the “middle-aged” Rockies (50-60 million years old). Erosion has had muck less time to work on the Tetons, comparatively, so their jagged peaks remain standing high.

Looking West across the Teton Valley and the Grand Teton Peak July of 2010

A 2.7 billion-year old metamorphic rock called gneiss makes up much of the Teton Range. These rocks were formed when sea floor sediments and volcanic debris were buried up to 28 km deep as two tectonic plates collided. The intense heat and pressure at these great depths changed or metamorphosed the sediments into today’ rocks, separating different minerals into lighter and darker layers.

I’m posing in the “Grand Teton National Park” during June of 2010

Meanwhile, molten magma began squeezing into cracks in the gneiss 2.5 billion years ago, and it cooled and crystallized to form igneous granite. This granite with it’s interlocking crystals was harder than gneiss forming the highest peaks in the central Teton Range, (Grand Teton, Middle Teton, and Mount Owen. Other peaks, such as Teewinot and Mount Moran, show stripes of darker and lighter gray where the granite cross-cuts the gneiss.

The Grand Teton Peak, the Middle Teton Peak and the South Teton Peak; (Looking west) July of 2010

Roughly 775 million years ago, the region stretched north to south, cracking the deeply buried gneiss and granite and forming a series of vertical, east-west trending cracks.

The geological cross-section of Teton National Park after the 775 million year ago stretching episode. (A USGS public domain image)

As the Teton region stretches in an east-west direction, this stress builds to a breaking point and generates an earthquake, lifting the mountain block skyward while dropping the valley floor.

Looking east on the west-side of the Grand Teton Peak and the Middle Teton Peak, picture taken 2017.

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