What is magnetic lineation?
In deformed rocks, magnetic lineations are generally considered to be the result of either bedding and cleavage intersection or they parallel the tectonic extension direction in high strain zones.
What is the difference between lineation and foliation?
Foliation is the result of the parallel arrangement of (micas, etc.) in a plane perpendicular to the maximum principal applied stress. A lineation is caused by a similar growth of elongate minerals (eg. Slate, schist, and gneiss are three common foliated metamorphic rocks.
What is lineation in structural geology?
Lineation is a general term to describe any repeated, commonly penetrative and parallel alignment. of linear elements within a rock (to envision lineation, imagine packages of spaghetti). A lineation. may be a primary igneous or sedimentary fabric element, such as an array of elongate K-feldspar.
What is Lineation foliation?
Foliation and Lineation. Foliation is a term used that describes minerals lined up in planes. If the minerals line up and point in a common direction, but with no planar fabric, this is lineation. When minerals lie on a plane AND point in a common direction; this is both foliation and lineation.
What is meant by Lineation?
1a : the action of marking with lines : delineation. b : outline. 2 : an arrangement of lines.
What are the three types of foliation?
There are three types of foliated rocks: slate, schist, and gneiss.
Why is lineation used?
Lineation is one of many devices poets use to emphasize or subordinate meaning, to orchestrate ambiguities, and to encourage the interpretations they desire while closing off unwanted avenues. Lineation shapes readers’ involvement in and understanding of a poem.
What are the two types of foliation?
There are three types of foliated rocks: slate, schist, and gneiss. Each type varies based on the size of the mineral grain and how foliation is characterized.
What is a lineation poem?
The technique of making lines of verse that involves also the rationale for breaking the lines, whether by closure (coming to the end of the phrase, clause, or sentence at the end of the line) or by enjambment (continuing the sentence beyond the line boundary, into the next line) (Kinzie, 1999).
How is Porphyroblast formed?
A large crystal that is surrounded by a finer-grained matrix in a metamorphic rock. Porphyroblasts form by the recrystallization of existing mineral crystals during metamorphism. They are analogous to phenocrysts in igneous rock.
Is there a strong lineation or weak foliation?
• There is no or only weak lineation L-tectonite- Alignment of linear fabric elements creates the dominant fabric, so the rock may split into rod-like shapes. • There is no or only weak foliation. L/S-tectonite- a strong foliation and a strong lineation.
How are foliation and lineation elements related in rock fabric?
Random- fabric elements (dark, elongate crystals) have long axes that are not parallel to one another. Preferred – Particular elements, such as long axes of elongate crystals are aligned with one another. Foliation- fabric elements are planar and essentially parallel to one another, creating a 2-dimensional fabric.
Which is an example of a lineation in a rock?
Lineation- fabric elements are linear; in this example, fabric elements are aligned in single planes L0, L1, L2 … Penetrative fabric; TectonitesFig. 11.3 10/21/2014© EarthStructure (2nded) 5 S-tectonite- Dominantly a foliation; rock may tend to split into sheets parallel to the foliation. • There is no or only weak lineation
What is the degree of foliation in a rock?
• The degree of foliation development, from compaction fabric to strong cleavage, can be characterized by distributions of a rock’s maximum and minimum magnetic-susceptibility axes. Disjunctive cleavage 10/21/2014© EarthStructure (2nded) 15