on April 16, 2022
Why do some geoscientists refer to focal mechanisms as beach balls?
GeologyWhen an earthquake occurs, seismologists create graphics of focal mechanisms, informally referred to as beach balls,to show the faulting motions that produce the earthquake. They use the patterns of compressions and dilatations received by seismometers. How do focal mechanisms work? A focal mechanism, or “beachball”, is a graphic symbol that indicates the type of slip
on April 16, 2022
How long did the last Ice Age last and when did it end?
GeologyThe last ice age is a period of global cooling, or glaciation, which characterizes the end of the Pleistocene on the whole planet. It began 115,000 years ago and ended 11,700 years ago, when the Holocene began. It corresponds to stages 2, 3, 4 and 5a-d of the isotopic chronology, developed at the end of
on April 16, 2022
What is the least understood era of Earth history?
GeologyThe Precambrian is the least understood part of Earth history, yet it is arguably the most important. Precambrian time spans almost nine- tenths of Earth history, from the formation of the Earth to the dawn of the Cambrian Period. It represents time so vast and long ago that it challenges all comprehension. What was the
on April 16, 2022
Is granite rock porous?
GeologyGranite is relatively non-porous compared to other common countertop materials, though it still has some porosity. Limestone and sandstone are highly porous and readily absorb liquids, and are particularly prone to etching, and wearing away when they come into contact with acids. Can granite be porous? Granite is a porous material—but this is not necessarily
on April 16, 2022
How do you think magma turns into extrusive igneous rock?
GeologyMagma that cools quickly forms one kind of igneous rock, and magma that cools slowly forms another kind. When magma rises from deep within the earth and explodes out of a volcano, it is called lava, and it cools quickly on the surface. Rock formed in this way is called extrusive igneous rock. How does
on April 16, 2022
What does lodestone mean in science?
Geologynoun. a variety of magnetite that possesses magnetic polarity and attracts iron. a piece of this serving as a magnet. something that attracts strongly. What is lodestone science? Abstract. The lodestone is an extremely rare form of the mineral magnetite (Fe3O4) that occurs naturally as a permanent magnet. It therefore attracts metallic iron as well
on April 16, 2022
What forms at a convergent subduction boundary?
GeologyIf two tectonic plates collide, they form a convergent plate boundary. Usually, one of the converging plates will move beneath the other, a process known as subduction. Deep trenches are features often formed where tectonic plates are being subducted and earthquakes are common. What does a subduction boundary form? Oceanic crust is denser than continental
on April 16, 2022
What are the 4 ways minerals are formed?
GeologyThe four main categories of mineral formation are: (1) igneous, or magmatic, in which minerals crystallize from a melt, (2) sedimentary, in which minerals are the result of sedimentation, a process whose raw materials are particles from other rocks that have undergone weathering or erosion, (3) metamorphic, in which … What are the 3 ways
on April 16, 2022
Is sandstone clastic or non clastic?
Geologyclastic sedimentary rocksclastic sedimentary rocks are sandstone and conglomerate. Some clastic sedimentary rocks (such as shale and mudstone) are fine enough that the individual grains cannot be distinguished. These fine-grained rocks are said to have an aphanitic texture. Is sandstone a clastic? Sandstone Basics The sediment particles are clasts, or pieces, of minerals and fragments
on April 16, 2022
When was Continental Drift accepted?
GeologyThe first truly detailed and comprehensive theory of continental drift was proposed in 1912 by Alfred Wegener, a German meteorologist. Bringing together a large mass of geologic and paleontological data, Wegener postulated that throughout most of geologic time there was only one continent, which he called Pangea. When did continental drift become accepted? Wegener first