What are the three ways the crust is exposed to stress?
GeologyThe three main types of stress are typical of the three types of plate boundaries: compression at convergent boundaries, tension at divergent boundaries, and shear at transform boundaries. Where rocks deform plastically, they tend to fold. What cause the stress in Earth’s crust? When plates collide, move apart, and slide past each other, lots of
What are the types of volcano according to the shape of their cones?
GeologyThere are three types of volcanoes: cinder cones (also called spatter cones), composite volcanoes (also called stratovolcanoes), and shield volcanoes. Figure 11.22 illustrates the size and shape differences amongst these volcanoes. Shield volcanoes, which get their name from their broad rounded shape, are the largest. What are the 4 types of volcano based from its
How did Dr Wegener die?
Geologyheart failureheart failure brought on by overexertion. What happened to Alfred Wegener’s body? Wegener’s friends left his body as they found it and built an ice-block mausoleum over it. Later they erected a 20-foot iron cross to mark the site. All have long since vanished beneath the snow, inevitably to become part of the great
How does rockfall happen?
GeologyRockfalls typically occur in rock cut slopes when rock blocks become dislodged by weather, flowing water, or due to the surrounding rocks and soil being eroded. Because of the irregular, unpredictable nature of rock joints and weathering patterns, rockfalls cannot be precisely predicted. What causes rockfall landslides? Landslides can be initiated in slopes already on
What does Eocene Epoch mean?
GeologyWhat is the meaning of Eocene Epoch? Eocene Epoch, second of three major worldwide divisions of the Paleogene Period (66 million to 23 million years ago) that began 56 million years ago and ended 33.9 million years ago. It follows the Paleocene Epoch and precedes the Oligocene Epoch. What is the Eocene Epoch known for?
What is the group name for the mineral pyroxene?
GeologyPyroxene minerals crystallize in both the monoclinic and orthorhombic crystal systems. Monoclinic pyroxenes are known as “clinopyroxenes” and orthorhombic pyroxenes are known as “orthopyroxenes”.… Orthorhombic Pyroxenes (Orthopyroxenes) Hypersthene (Mg,Fe)SiO3 Protoenstatite Mg2Si2O6 Is among the pyroxene group mineral? Structure. Pyroxenes are the most common single-chain silicate minerals. (The only other important group of single-chain silicates, the
Who created the principle of faunal succession?
GeologyWilliam SmithWilliam Smith, that different strata each contain particular assemblages of fossils by which the rocks may be identified and correlated over long distances; and that these fossil forms succeed one another in a definite and habitual order. Who develops the principle of faunal succession? The concept was derived from an 1812 study of the
What was Harry Hess’s discovery?
GeologyHarry Hess was a geologist and Navy submarine commander during World War II. Part of his mission had been to study the deepest parts of the ocean floor. In 1946 he had discovered that hundreds of flat-topped mountains, perhaps sunken islands, shape the Pacific floor. What did Harry Hess invent? Henry (also known as Harry)
What rock type is found at Dartmoor National Park?
Geology– granitegranite. This granite was intruded during the late Carboniferous/ early Permian Period (around 280 million years ago) into the area we now know as Devon and Cornwall. What is Dartmoor granite? The Dartmoor granite is the classic igneous rock, composed of interlocking crystals of white orthoclase Page 2 Dartmoor National Park Authority Dartmoor granite
What does Aphanitic texture mean?
GeologyAphanitic – This texture describes very fine grained rock where individual crystals can be seen only with the aid of a microscope, i.e. the rock is mostly groundmass. An aphanitic texture is developed when magma is erupted at the Earth’s surface and cools too quickly for large crystals to grow. What has an aphanitic texture?