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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]
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).
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 ...
Stone has been used to make a wide variety of tools throughout history, including arrowheads, spearheads, hand axes, and querns. Knapped stone tools are nearly ubiquitous in pre-metal-using societies because they are easily manufactured, the tool stone raw material is usually plentiful, and they are easy to transport and sharpen.
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).
In the west, the Columbia River Basalts are just that: almost exclusively black basalt. Not so in the Snake River Plain, where relatively quiet eruptions of soupy black basalt lava flows alternated with tremendous explosive eruptions of rhyolite, a light-colored volcanic rock. [8] Cinder cones dot the landscape of the Snake River Plain.
In archaeology, a prismatic blade is a long, narrow, specialized stone flake tool with a sharp edge, like a small razor blade. [1] Prismatic blades are flaked from stone cores through pressure flaking or direct percussion. [2] This process results in a very standardized finished tool and waste assemblage.
Columbia River Basin. Wallula Gap (/ w ə ˈ l uː l ə /) is a large water gap of the Columbia River in the Northwestern United States, in Southeastern Washington.It cuts through the Horse Heaven Hills basalt anticlines in the Columbia River Basin, just south of the confluence of the Walla Walla and Columbia rivers.