Mineralogical norm calculations applied to tropical weathering profiles

作     者：Voicu, G Bardoux, M Voicu, D 

作者机构：UNIV MONTREALDEPT INFORMATMONTREALPQ H3C 3J7CANADA 

出 版 物：《MINERALOGICAL MAGAZINE》 (矿物学杂志)

年 卷 期：1997年第61卷第2期

页      面：185-196页

核心收录：

学科分类：0709[理学-地质学] 070901[理学-矿物学、岩石学、矿床学] 07[理学] 

主　　题：mineralogical norm whole-rock analyses tropical weathering profile computer program 

摘      要：In contrast with igneous and metamorphic rocks, classical petrochemical calculation methods cannot be used for tropical weathering components (saprolite, bauxitic, ferruginous, siliceous and calcareous laterite) in converting whole-rock chemical analyses into normative mineralogical weight percentages. Weathering profiles are characterized by a mixture of primary and secondary minerals, which are not considered in the classical methods of mineralogical norm calculation. A new petrochemical calculation algorithm is proposed for the conversion of whole-rock chemical analyses into weathering norm (WN) for several components of the tropical weathering profiles. The normative minerals are represented by three primary minerals, six secondary minerals, four primary/secondary mineral pairs, and five minerals which can have both primary and secondary origin. This algorithm has been used in MINNOR, a WINDOWS application written in Visual Basic, which calculates the mineralogical norm. In order to test the program, several types of different chemical weathering profiles from South America and Africa have been selected. Special attention is paid to the weathering profile from Omai, Guyana, South America.