A close-up view of Angels Window, the most accessible natural arch in the North Rim of the Grand Canyon, Arizona, USA. It is on the Cape Royal Trail.
Kaibab Limestone is the current top of the Grand Canyon and is composed mostly of a sandy limestone, with some sandstone and shale thrown in for good measure. This means that it was probably formed in a shallow sea and rose as the meeting of the the North American and Pacific Plates pushed the land up. During the uplift of the Kaibab Plateau, the pressures of the earth caused the rock to fracture, forming vertical joints that intersected with the horizontal bedding planes.
Weathering (rain, freezing, thawing) eroded along the vertical joints of the limestone and the horizontal bedding planes to form a hole and enlarged to form the arch itself, a natural bridge that extends out over the Canyon.
Geocaching
Visitors can walk along a paved trail over the top of the arch to a viewpoint offering what many people consider to be the best view over the Grand Canyon.
Both photos on this page are copyright © Liz Leyden. All rights strictly as agreed in writing with the author or her agent.
The main, close-up photo of Angels Window is available to license as a stock photo from iStock. The smaller, wider, view is also licensable from iStock.
