what is "gneissic banding"? course hero

What does it mean when a rock is banding?

Banding means that the rock consists of alternating, thin layers (typically 1 mm to 1 cm) of two different mineral compositions. Normally, the two types of layers have the same kinds of minerals, but in different proportions, giving the rock a striped appearance.

What is compositional banding?

Abstract. Compositional banding produced by metamorphic differentiation has long been understood to result from mass transport by either dissolution or diffusion under the influence of a non-hydrostatic stress field.

What process causes banding?

Banding is caused by segregation of the alloying elements during solidification. Subsequent hot-working operations result in segregation aligned in the direction of working, which results in the banded appearance delineated in the microstructure.

What is a foliated rock with gneissic banding composed of feldspar mica and quartz?

Gneiss is a foliated metamorphic rock that has a banded appearance and is made up of granular mineral grains. It typically contains abundant quartz or feldspar minerals.

What is gneissic banding?

Gneiss is a metamorphic rock form characterized by banding caused by segregation of different types of rock, typically light and dark silicates. Rather than an indication of specific mineral composition, the term is an indication of texture. The "gneissic texture" refers to the segregation of light and dark minerals.

What is gneissic foliation?

Foliation among the gneisses appears as distinct alternating bands of platy minerals and coarse-grained minerals; however, gneisses do not split, or cleave, along their planes as schists do. Few contact-metamorphic rocks (which form when an intrusion of igneous rock meets an existing rock mass) are foliated.

What is technology banding?

Technology banding is a methodology for ensuring that future equipment and systems are equivalent to those the client site has contracted for.

How do Foliations and banding develop?

As the minerals that form this foliation grow, they begin to break up the original beds into small pods. As the pods are compressed and extended, partly by recrystallization, they could eventually intersect again to form new compositional bands parallel to the new foliation.

What is banding in igneous rocks?

Banding is common in silicic volcanic rocks and preserves a record of deforma- tion associated with magma ascent, eruption, and emplacement. Alternating light and dark bands ranging in width from tens of microns to decimeters are usually caused by differences in composition, crystallinity, or bubble content.

What is the difference between foliated and non-foliated rocks?

​Foliated metamorphic rocks​ exhibit layers or stripes caused by the elongation and alignment of minerals in the rock as it undergoes metamorphism. In contrast, ​nonfoliated metamorphic rocks​ do not contain minerals that align during metamorphism and do not appear layered.

How does the banding in gneiss form?

Gneiss (from Old German, ''gneist'' for spark) is a metamorphic rock that is characterized and define by its bands. These bands are created by foliation when extreme pressure aligns the platy and elongated crystals from the parent rocks.

What type of rock is banded gneiss?

metamorphic rockGneiss is a coarse to medium grained banded metamorphic rock formed from igneous or sedimentary rocks during regional metamorphism. Rich in feldspars and quartz, gneisses also contain mica minerals and aluminous or ferromagnesian silicates.

What causes banding in hair?

It may seem like the right thing to do, but waiting an extra week to touch up your roots can result in a weird color effect called banding. This phenomenon, also known as the halo effect, happens when new hair has grown out too far from the scalp resulting in an uneven dye job.

What is banding in human resource?

Banding refers to the procedure of grouping test scores into ranges and treating scores within a particular range as equivalent when making personnel decisions. After an organization collects test scores from candidates who applied for a job, a hiring decision must be made using these scores.

What is called banding?

banding - an adornment consisting of a strip of a contrasting color or material. stripe, band. adornment - a decoration of color or interest that is added to relieve plainness.

What does banding mean in medical terms?

Banding is a medical procedure which uses elastic bands for constriction. Banding may be used to tie off blood vessels in order to stop bleeding, as in the treatment of bleeding esophageal varices.

What Is Gneiss?

Gneiss is a metamorphic rock, characterized by its bands as seen in the image below. The banded appearance of gneiss is what defines it.

The Formation of Gneiss

Gneiss is a metamorphic rock, a type of rock formed by high amounts of heat and pressure that occur deep in the Earth's crust. Gneiss is known as a high-grade metamorphic rock, which means that is exposed to high amounts of heat and pressure compared to other types of metamorphic rock that are lower grade.

Mineral Composition and Classification

Gneiss is defined by its banding but there are certain minerals that are typically found in gneiss. These minerals form as gneiss because of the parent rock composition and they include:

Uses of Gneiss

Because gneiss does not usually split along planes of weakness like other metamorphic rocks, it is typically used for things like crushed stone. The crushed stone can be used in construction of roads or buildings or in landscaping projects.

What is course hero?

Conceived by students at Cornell, Course Hero provides access to old tests, homework problems, textbook answers and class notes. It also offers the ability to form study groups where you can share files and exchange ideas. It’s basically a forum where you can put up old schoolwork you’ve done and see the old schoolwork of your peers from your own school and around the nation.

What are the problems with Course Hero?

One of the big problems with Course Hero is that if a student wants to cheat, the website offers all the tools they need to do so. It provides a temptation to students who are looking for exam answers and want to cheat in class.

How does Course Hero help you?

You can choose to study through the internet, or meet at a physical table and chairs on campus. In this way, Course Hero allows you to make connections with others who you can help, and who can help you.

Is Course Hero free?

Course Hero isn’t really free. While you can create an account for no cost, you can’t view anything until you pay in one of two ways: By posting materials (40 documents = 1 month free) By paying a monthly, 6 month, or yearly fee.

Can you track someone on Course Hero?

You also can’t track who is using Course Hero. Often, notes are posted anonymously, so the individual who posted them cannot be tracked down. This means that it’s harder to punish those who are blatantly cheating or difficult to tell if the resources available can really be trusted.

Is plagiarizing a violation of the Honor Code?

Many teachers define it in their syllabi and it is common knowledge that copying answers and plagiarizing are violations of the Honor Code and considered “unauthorized” assistance. But where is the line? Working in groups often facilitates learning in students, and contributes to the cohesiveness of a class. When working in groups, students often share answers, methods, notes and their understanding—all things that would be shared on Course Hero.

Why does Course Hero give correct answers?

Course Hero gives out correct answers because they involve tutors to provide solutions, especially for paid subscriptions. They have experienced tutors who answer all your questions correctly. However, some answers may be wrong since they are uploaded by students to get unlocks. This may compromise the quality of answers for other users.

Why is Course Hero used?

Course Hero, being used by many students, makes it possible for many students to submit an identical paper. When instructors come across similar papers submitted by different students, they are likely to know that the papers have been obtained from a similar source.

How to use Course Hero without cheating?

Students can use the content they get from Course Hero without cheating using the following ways: 1. Paraphrasing the answer. Paraphrasing involves using formulating an answer of your own. You will first read the answer provided on Course Hero, understand it, and try writing what you have understood on your own. 2.

What is copying from Course Hero?

When copying from Course Hero, you are also plagiarising. This is a form of academic dishonesty that can land you into trouble as well.

Why is course hero important?

Course Hero is a very important feature in every student’s academic life. This is only if it is used for the right reasons.

When answers are stated in short summaries, and not explained, can you use the points to come up with an?

When answers are stated in short summaries, and not explained, you can use the points to come up with an explanation of your own.

Can you use Course Hero against your instructor's will?

In institutions where the use of Course Hero is not specified, various instructors may be against the use of Course Hero. Using Course Hero against the will of your instructors is cheating. You will not be evaluated on the basis that the given test, assignment, or research was supposed to.