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Ironstone (sandstone with iron oxides) from the Mississippian Breathitt Formation, Mile Marker 166, I-64, Kentucky. Ironstone is a sedimentary rock, either deposited directly as a ferruginous sediment or created by chemical replacement, that contains a substantial proportion of an iron ore compound from which iron (Fe) can be smelted commercially.
Iron formations can be divided into subdivisions known as: banded iron formations (BIFs) and granular iron formations (GIFs). [ 3 ] The above classification scheme is the most commonly used and accepted, though sometimes an older system is used which divides iron-rich sedimentary rocks into three categories: bog iron deposits , ironstones , and ...
The characteristic of an Iron Age culture is the mass production of tools and weapons made not just of found iron, but from smelted steel alloys with an added carbon content. [ citation needed ] Only with the capability of the production of carbon steel does ferrous metallurgy result in tools or weapons that are harder and lighter than bronze .
The Armenian Plateau has been called the "epicenter of the Iron Age", since it appears to be the location of the first appearance of Iron Age metallurgy in the late 2nd millennium BC. [22] In the Early Iron Age, the Kingdom of Van controlled much of the region, until it was overthrown by the Medes and Orontid dynasty.
The plateau has a slight slant towards the northwest, making it higher on the eastern side. [2] A large portion of the plateau is a coalfield, which was formed approximately 320 million years ago during the Pennsylvanian Age. [3] The plateau was subjected to glaciation during the Pleistocene ice age. As a result, the topography of this section ...
The Canadian Shield (French: Bouclier canadien [buklje kanadjɛ̃]), also called the Laurentian Shield or the Laurentian Plateau, is a geologic shield, a large area of exposed Precambrian igneous and high-grade metamorphic rocks. It forms the North American Craton (or Laurentia), the ancient geologic core of the North American continent.
One of the fragments was made of bloomery iron rather than meteoritic iron. [37] [38] The earliest iron artifacts made from bloomeries in China date to end of the 9th century BC. [39] Cast iron was used in ancient China for warfare, agriculture and architecture. [9] Around 500 BC, metalworkers in the southern state of Wu achieved a temperature ...
Satellite image of the Tibetan Plateau between the Himalayan mountains to the south and the Taklamakan Desert to the north. In geology and physical geography, a plateau (/ p l ə ˈ t oʊ, p l æ ˈ t oʊ, ˈ p l æ t oʊ /; French:; pl.: plateaus or plateaux), [1] [2] also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the ...