What is a rock in geological terms?
rock, in geology, naturally occurring and coherent aggregate of one or more minerals. Such aggregates constitute the basic unit of which the solid Earth is composed and typically form recognizable and mappable volumes.
How do you describe rock layers?
Layered rocks form when particles settle from water or air. Steno’s Law of Original Horizontality states that most sediments, when originally formed, were laid down horizontally. Rock layers are also called strata (the plural form of the Latin word stratum), and stratigraphy is the science of strata.
What do geologists call the structure of rock?
Since the beginning of geologic studies more than 200 years ago, geologists have shown that rock layers in certain parts of the continents are folded, fractured, and deformed on a 167 gigantic scale.The large-scale shape, geometry, and deformation of rock bodies are part of what we call their structure.
Why do all rocks behave in the same way?
Rocks behave in the same way and deform in response to the forces applied to them. All of Earth’s rocks are under some type of stress, but in many situations the stress is equal in all directions and the rocks are not deformed.
Which is the most common type of rock without form?
Without form; applied to rocks and minerals which have no definite external crystalline structure. A mineral group that consists of common, dark-colored, rock-forming silicate minerals. The most common minerals are hornblende, tremolite, and actinolite.
Which is the best description of a rock mass?
A rock mass of large horizontal extent bounded by physically different material. a. Containing much organic, or at least carbonaceous matter, mostly in the form of the tarry hydrocarbons which are usually described as bitumen. b. Pertaining to bituminous coal.