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What is a fault line in geology?
A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the form of an earthquake – or may occur slowly, in the form of creep. Most faults produce repeated displacements over geologic time.
What 2 clues can geologists get from studying rock samples?
When studying a rock sample, geologists observe the rock’s color and texture and determine its mineral composition.
What clues tell geologists about extrusion?
Clues from Igneous Rocks: 1. Lava that hardens on the surface is called an Extrusion (example – an eruption would put a layer of igneous rock on top of sedimentary rocks. Rock layers below an extrusion are always older than the extrusion.
What can the geologist tell?
Geologists use these clues to figure out what is buried under the ground surface. This information can be used in many different ways. Geologists can look at how stones are lined up or the shape of ripples and tell which way the ancient river that deposited them was flowing.
What are the 5 types of faults?
There are different types of faults: reverse faults, strike-slip faults, oblique faults, and normal faults.
What 3 characteristics do geologists use to identify rocks?
To help with identification, geologists must look closely at the physical properties of a mineral. These properties can include: color, streak, hardness, cleavage, specific gravity, crystal form, and others.
Which is older intrusion or extrusion?
Lava that hardens on the surface is called an extrusion. The rock layers below an extrusion are always older than the extrusion. There, the magma cools and hardens into a mass of igneous rock called an intrusion. An intrusion is always younger than the rock layers around and beneath it.
What is the difference between intrusion and extrusion?
An intrusion is any body of intrusive igneous rock, formed from magma that cools and solidifies within the crust of the planet. In contrast, an extrusion consists of extrusive rock, formed above the surface of the crust.
Is being a geologist fun?
They study the history of the Earth in terms of materials, rocks, and minerals. It can be a very exciting and stimulating career choice for someone who is interested in the processes that shape the Earth’s surface such as volcanic eruptions, landslides, floods, and earthquakes.