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Deep sea mining is the extraction of minerals from the seabed of the deep sea. The main ores of commercial interest are polymetallic nodules , which are found at depths of 4–6 km (2.5–3.7 mi) primarily on the abyssal plain .
Sphalerite has been found as a pseudomorph, taking the crystal structure of galena, tetrahedrite, barite and calcite. [13] [15] Sphalerite can have Spinel Law twins, where the twin axis is [111]. The chemical formula of sphalerite is (Zn,Fe)S; the iron content generally increases with increasing formation temperature and can reach up to 40%. [6]
However, new fossils found in 2007 and 2008 showed that the "chain mail" of tommotiids formed the tube of a sessile animal; one tommotiid resembled phoronids, which are close relatives or a subgroup of brachiopods, while the other tommotiid bore two symmetrical plates that might be an early form of brachiopod valves.
A diverse array of ichnofossils have also been found at Joggins, including vertebrate trackways, invertebrate trace fossils, tunnel structures, rhizoliths, and possibly wood borings. [ 12 ] Fish coprolites are abundant in the limestone of the Joggins Formation, averaging lengths of 2–3 cm (0.79–1.18 in). [ 12 ]
The researchers found to their surprise that the fastest gait was kangaroo-like hopping (maximum simulated speed of 17.3 metres per second (62 km/h; 39 mph)), which they regarded as unlikely based on the size of the animal and lack of hopping footprints in the fossil record, and instead interpreted the result as indicative of an inaccuracy in ...
Lapis lazuli is found in limestone in the Kokcha River valley of Badakhshan province in north-eastern Afghanistan, where the Sar-i Sang mine deposits have been worked for more than 6,000 years. [20] Afghanistan was the source of lapis for the ancient Persian, Egyptian and Mesopotamian civilizations, as well as the later Greeks and Romans.
Argentinosaurus (meaning "lizard from Argentina") is a genus of giant sauropod dinosaur that lived during the Late Cretaceous period in what is now Argentina.Although it is only known from fragmentary remains, Argentinosaurus is one of the largest known land animals of all time, perhaps the largest, measuring 30–35 m (98–115 ft) long and weighing 65–80 t (72–88 short tons).