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Mt. Cayley massif, south aspect. The volcano resides in the middle of a north–south trending zone of volcanism called the Mount Cayley volcanic field. [3] It consists predominantly of volcanoes that formed subglacially during the Late Pleistocene age, such as Pali Dome, Slag Hill, Ring Mountain and Ember Ridge, but activity continued at Pali Dome and Slag Hill into the Holocene epoch.
John Day Fossil Beds National Monument is a U.S. national monument in Wheeler and Grant counties in east-central Oregon.Located within the John Day River basin and managed by the National Park Service, the park is known for its well-preserved layers of fossil plants and mammals that lived in the region between the late Eocene, about 45 million years ago, and the late Miocene, about 5 million ...
Debris flows with volumes ranging up to about 100,000 cubic meters occur frequently in mountainous regions worldwide. The largest prehistoric flows have had volumes exceeding 1 billion cubic meters (i.e., 1 cubic kilometer). As a result of their high sediment concentrations and mobility, debris flows can be very destructive.
Tell Barri, northeastern Syria, from the west; this is 32 meters (105 feet) high, and its base covers 37 hectares (91 acres) Tel Be'er Sheva, Beersheva, Israel. In archaeology, a tell (from Arabic: تَلّ, tall, 'mound' or 'small hill') [1] is an artificial topographical feature, a mound [a] consisting of the accumulated and stratified debris of a succession of consecutive settlements at the ...
Brokeoff Volcano was active from 590,000 to 387,000 years ago, during which period it erupted numerous flows with compositions ranging from basaltic andesite to dacite. At its peak, Brokeoff Volcano reached an estimated height of 3,350 metres (10,990 ft) and had a basal circumference of approximately 12 kilometres (7.5 mi).
He then compared the counts and weights of experimental samples with debris from two prehistoric workshop sites in western North Dakota. The result shows the experimental data sets can explain the technological composition of archaeological samples. Samples from several other sites also are applied this method and derive clear discriminant results.
Prehistoric sector collapses are stored in the geological record [1] in the form of debris avalanche deposits [2] and collapse scars. Debris avalanche deposits can be found up to 20 km from the site of collapse. [3] Studying avalanche deposits informs on the time scale of the collapse and the volcano from which it originated. [2]
The 1st to 13th lobes were named in the order they were formed. Collapsing of the lava dome began to occur when the lobes, pushed out by the newly supplied magma, started to give way on the slope, causing a phenomenon known as pyroclastic flows (in which debris and volcanic gasses flow down the mountainside at speeds of 100 km/h).