## Abstract

At 25oC, silicate dissolution rates are pH dependent and vary widely from one mineral to another. At high T (300-700oC), however, the available data indicate that most minerals dissolve in aqueous and H_{2}O-CO_{2} fluids with similar rate constants if their rates are normalized to a constant number of oxygen gramme atoms. These observations suggest the presence of a compensation relationship between pre-exponential and activation energy terms in the Arrhenius equation. A semiempirical correlation is noted between 25oC dissolution rate constants and the entropy per unit volume (So/Vo) of the dissolving mineral. At T >300oC, the relationship is summarized by the equation log k = -2900/T - 6.85 g atom oxygen cm^{-2} s^{-1}. Uses of this equation show that isograd reactions go to completion with minimal T overstep (0.13oC for a 10oC/m.y. event) provided a fluid transporting medium is present.-R.A.H.

Original language | English |
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Pages (from-to) | 194-211 |

Number of pages | 18 |

Journal | Unknown Journal |

Publication status | Published - 1986 |