Felsic - Wikipedia
In geology, felsic is a modifier describing igneous rocks that are relatively rich in elements that form feldspar and quartz. [1] It is contrasted with mafic rocks, which are relatively richer in magnesium and iron .
Felsic and mafic rocks | Igneous, Granitic & Rhyolitic Types
Felsic rocks are commonly oversaturated and contain free quartz (SiO 2), intermediate rocks contain little or no quartz or feldspathoids (undersaturated minerals), and mafic rocks may contain abundant feldspathoids. This broad grouping on the basis of mineralogy related to silica content is used in many modern classification schemes.
Quartz - Wikipedia
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO 4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO 2.
Igneous Rocks – Types, Properties, and Examples - Science Notes …
2024年1月31日 · 1. Felsic Igneous Rocks. Definition: Felsic rocks are rich in silica (over 65%) and contain a high proportion of lighter minerals like quartz and feldspar. The term “felsic” derives from “feldspar” and “silica”. Characteristics: These rocks are generally light in color, ranging from white to pink or light grey. They have a high ...
4.1: Classification of Igneous Rocks - Geosciences LibreTexts
Felsic refers to a predominance of the light-colored (felsic) minerals feldspar and silica in the form of quartz. These light-colored minerals have more silica as a proportion of their overall chemical formula.
3.4 Classification of Igneous Rocks – Physical Geology
If we focus on the non-ferromagnesian silicates, it is evident that felsic rocks can have from 0% to 35% K-feldspar, from 25% to 35% quartz (the vertical thickness of the quartz field varies from 25% to 35%), and from 25% to 50% plagioclase (and that …
5.3: Igneous Rock Classification - Geosciences LibreTexts
2024年4月11日 · Felsic refers to a composition with a majority of the light-colored minerals feldspar and quartz. Minor amounts of dark-colored (ferromagnesian) minerals like amphibole and biotite mica may be present as well.
Felsic Rock Composition and Examples | Geology Base
2023年12月10日 · Felsic rocks are silica-rich rocks high in minerals like quartz, feldspars, or muscovite and relatively low iron and magnesium minerals. Usually, rocks classified as felsic have at least 75% felsic minerals. These minerals are orthoclase, quartz, and plagioclase. Those with more than 90% are leucocratic. Felsic rocks are usually light-colored.
4.3 Classification of Igneous Rocks – Principles of Earth Science
Igneous rocks can be divided into four categories based on their chemical composition: felsic, intermediate, mafic, and ultramafic. The diagram of Bowen’s reaction series (Figure 4.6) shows that differences in chemical composition correspond to differences in the types of minerals within an igneous rock.
4.3 Classification of Igneous Rocks
Igneous rocks are classified into four categories: felsic, intermediate, mafic, and ultramafic, based on either their chemistry or their mineral composition. The diagram in Figure 4.3.1 can be used to help classify igneous rocks by their mineral composition.