Difference between revisions of "Basic rock"

'''basic rock''' ([[Category:Noun]][[:Category:Noun|noun]], ''pl.'' basic rocks; [[Category:Ecology term]][[:Category:Ecology term|ecology term]], [[Category:Substrate term]][[:Category:Substrate term|Substrate term]]) – (1) ''mineralogical:'' a rock with a low content of acidic minerals, i. e., containing only small amounts or entirely lacking SiO2; (2) ''chemical:'' a rock with a high pH. ''Note:'' an ambiguous term; sometimes imprecisely used to refer only to the pH of a rock [[substrate]]; the mineralogical definition should be preferred because it includes the chemical composition of a rock; if the pH reaction needs to be emphasized it should be referred to as "a rock with a high pH" not as a "basic rock"; the two definitions are often ''not'' identical, e. g., the ''mineralogy'' of a basalt is ''basic'' because it has a low content of SiO2-minerals, nevertheless a basalt has a low (or neutral) but never a high, "basic" pH. In lichenology the definition has often erroneously been used to refer to [[calcareous]] rocks, i. e., rocks characterized by the presence of [[calcite]]s (testing positive ("bubbling") if a 10% solution of HCl is applied top the surface).