acid and basic rocks


acid and basic rocks
Division of igneous rocks on the basis of their silicate mineral content, these minerals usually being the most abundant in such rocks.

Rocks are described as acid, intermediate, basic, and ultrabasic, in order of decreasing silica content, because it was earlier thought that silica is present in rock magmas in the form of silicic acid. In modern usage the terms do not refer to acidity in the chemical sense. In general, the gradation from acid to basic corresponds to an increase in colour (i.e., light to dark).

* * *


Universalium. 2010.

Look at other dictionaries:

  • basic — /bay sik/, adj. 1. of, pertaining to, or forming a base; fundamental: a basic principle; the basic ingredient. 2. Chem. a. pertaining to, of the nature of, or containing a base. b. not having all of the hydroxyls of the base replaced by the acid… …   Universalium

  • acid — acidly, adv. acidness, n. /as id/, n. 1. Chem. a compound usually having a sour taste and capable of neutralizing alkalis and reddening blue litmus paper, containing hydrogen that can be replaced by a metal or an electropositive group to form a… …   Universalium

  • BASIC — /bay sik/, n. Computers. a widely adopted programming language that uses English words, punctuation marks, and algebraic notation to facilitate communication between the operator or lay user and the computer. [1965 70; B(eginner s) A(ll purpose)… …   Universalium

  • basic — /ˈbeɪsɪk/ (say baysik), Chiefly US /ˈbæsɪk/ (say basik) adjective 1. of, relating to, or forming a base; fundamental: a basic principle; a basic ingredient. 2. (of manufactured commodities) equipped with essential components, without optional… …   Australian English dictionary

  • Primary rocks — Primary Pri ma*ry, a. [L. primarius, fr. primus first: cf. F. primaire. See {Prime}, a., and cf. {Premier}, {Primero}.] 1. First in order of time or development or in intention; primitive; fundamental; original. [1913 Webster] The church of… …   The Collaborative International Dictionary of English

  • primitive rocks — Primary Pri ma*ry, a. [L. primarius, fr. primus first: cf. F. primaire. See {Prime}, a., and cf. {Premier}, {Primero}.] 1. First in order of time or development or in intention; primitive; fundamental; original. [1913 Webster] The church of… …   The Collaborative International Dictionary of English

  • Formation of rocks — This article discusses how rocks are formed. There are also articles on physical rock formations, also known as strata, and the formal naming of geologic formations. The three main ways rocks are formed: * Sedimentary rocks are formed through the …   Wikipedia

  • Timeline of Islamic science and engineering — This timeline of Islamic science and engineering covers the general development of science and technology in the Islamic world during the Islamic Golden Age, usually dated from the 7th to 16th centuries.From the 17th century onwards, the advances …   Wikipedia

  • Mathematics and Physical Sciences — ▪ 2003 Introduction Mathematics       Mathematics in 2002 was marked by two discoveries in number theory. The first may have practical implications; the second satisfied a 150 year old curiosity.       Computer scientist Manindra Agrawal of the… …   Universalium

  • Anthropology and Archaeology — ▪ 2009 Introduction Anthropology       Among the key developments in 2008 in the field of physical anthropology was the discovery by a large interdisciplinary team of Spanish and American scientists in northern Spain of a partial mandible (lower… …   Universalium


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.