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The Columbia River Basalt Group (including the Steen and Picture Gorge basalts) extends over portions of four states. The Columbia River Basalt Group (CRBG) is the youngest, smallest and one of the best-preserved continental flood basalt provinces on Earth, covering over 210,000 km 2 (81,000 sq mi) mainly eastern Oregon and Washington, western Idaho, and part of northern Nevada. [1]
In contrast to the production of core tools like handaxes, where cores themselves were the end product shaped and trimmed down by removal of flakes, in prepared-core technique large flakes are the product and the core is used to produce them. This shift made it faster and more resource-efficient, as multiple tools could be struck from a single ...
The earliest stone tools to date have been found at the site of Lomekwi 3 (LOM3) in Kenya and they have been dated to around 3.3 million years ago. [1] The archaeological record of lithic technology is divided into three major time periods: the Paleolithic (Old Stone Age), Mesolithic (Middle Stone Age), and Neolithic (New Stone Age).
Chopping tools. In archaeology a chopping tool is a stone tool. Stone tools are usually dated by determining the age of the find context e.g. by carbon-14 dating and potassium–argon dating. The oldest stone tools are about 3 million years old. Chopping tools mainly occur in the Olduwan (2.9 to 1.6 million years ago).
The Ringold Formation represents sand and gravel placed by the Columbia River between 9 and 3 million years ago. These deposits overlay cooled lava erupted as part of the Columbia River Basalt Group, a type of volcanic eruption known as flood basalts erupting from fissures across eastern Washington and Oregon that were unrelated to the Cascade Range. [11]
Moses Coulee in the US showing multiple flood basalt flows of the Columbia River Basalt Group. The upper basalt is Roza Member, while the lower canyon exposes Frenchmen Springs Member basalt A flood basalt (or plateau basalt [ 1 ] ) is the result of a giant volcanic eruption or series of eruptions that covers large stretches of land or the ...
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To create this tool, one would have to use a hammerstone to chip away flakes on the stone to create a side of the stone with a very sharp edge, allowing for the cutting and hacking of an object. This is a unique type of lithic reduction, as only a single side of the stone is retouched to produce the cutting surface of the stone. The side that ...