on April 16, 2022
Why are tectonic plates like the pieces of a jigsaw puzzle?
GeologyThe biggest jigsaw puzzle in the solar system has a split personality: The number and sizes of Earth’s tectonic plates can flip, according to a new study. Today, the pieces of Earth’s broken shell are unequal in size. Of about 50 plates, a mere seven account for 94 percent of the surface. How is plate
on April 16, 2022
What are the basic principles of plate tectonics?
GeologyThere are various basic principles underlying the theory of plate tectonics. The fundamental principles include: the plates; the Wilson cycle; convection; the lithosphere and the astehnosphere; and the plate tectonic boundaries. This constitutes the earth’s outermost layer, the crust and the upper mantle. What are three main concepts of the theory of plate tectonics? The
on April 16, 2022
Where does the name Terra come from?
GeologyTerra as a girl’s name is of Latin origin meaning “Earth”. In mythology, Terra is the Roman earth goddess and equivalent to the Greek Gaia. Where did the name Terra come from? From the Latin terra – with origins in the Proto-Indo-European ters-, meaning “dry” – the Romance languages derived their word for Earth, including
on April 16, 2022
Where does a fault occur?
GeologyFaults are defined by the kind of motion that happens where they are. Normal faults show cracks where one block of rock is sliding down and away from another block of rock. These faults usually occur in areas where the crust is very slowly stretching or where two plates are pulling away from each other.
on April 16, 2022
How is a gryke formed?
GeologyGrykes are formed by acid erosion from water percolating through existing cracks and joints in the alkaline rocks. Over time this erosion widens and deepens the cracks forming a distinctive flagstone-like formation [see also Clint]. What is the difference between a Clint and a gryke? Pavements are made up of two separate but integral parts
on April 16, 2022
How many times has Nevado del Ruiz erupted?
GeologyDuring the past 11,000 years, Nevado del Ruiz passed through at least 12 eruption stages, which included multiple slope failures (rock avalanches), pyroclastic flows and lahars leading to partial destruction of the summit domes. Is the Nevado del Ruiz volcano active? The Colombian volcano Nevado del Ruiz is an active stratovolcano with a history of
on April 16, 2022
What crystal system does halite belong to?
GeologyHalite is a common evaporite mineral, NaCl, used as table salt worldwide. It is arguably the most well-known mineral in the world. It has a formula unit composition of NaCl, and is in the cubic crystal system. What group does halite belong to? The halides group of minerals are salts of sodium, fluoride, and hydrochloric
on April 16, 2022
What are the different types plate boundaries?
GeologyMost seismic activity occurs at three types of plate boundaries—divergent, convergent, and transform. As the plates move past each other, they sometimes get caught and pressure builds up. What are 4 types of plate boundaries? Tectonic Plates and Plate Boundaries Convergent boundaries: where two plates are colliding. Subduction zones occur when one or both of
on April 16, 2022
What is abrasion and attrition?
GeologyAbrasion occurs as a result of two surfaces rubbing against each other resulting in the wearing down of one or both of the surfaces. However, attrition refers to the breaking off of particles (erosion) which occurs as a result of objects hitting against each other. What is attrition and abrasion in dentistry? Tooth wear is
on April 16, 2022
What started the Archean eon?
GeologyThe Archean Eon began about 4 billion years ago with the formation of Earth’s crust and extended to the start of the Proterozoic Eon 2.5 billion years ago; the latter is the second formal division of Precambrian time. Why did the Archean Eon start? The Archean Eon ( /ɑːrˈkiːən/ ar-KEE-ən, also spelled Archaean or Archæan)