Mineral authigenic

Cavaretta, G., Gianelli, G. and Puxedolu, M. (1982) Formation of authigenic minerals and their use as... 

Shimazu, M. (1971) On the authigenic minerals in the spilitic basalts in the inner belts of northeastern Japan. Proc, IMA-IAGOD Meeting 70, IMA Vol. Mineralog. Soc. Japan, Spec. Paper 1, 134-139. 

Dequincey O, Chabaux F, Clauer N, Liewig N, Muller J-P (1999) Dating of weathering profiles by radioactive disequilibria contribution of the study of authigenic mineral fractions. CR Acad Sci Paris... 

FIGURE 3.3 Reduction in porosity in sandstone as a result of cementation and growth of authigenic minerals in the pores which affects the amount, size, and arrangement of the pores. (Modified after Ebanks, 1987.)... 

The sandstones studied contain different types of cements, such as clay, quartz and carbonate cements. Clay cements are often a mixture of alio- and authigenic minerals. Kaolinite is the main component... 

Isotopic composition of authigenic minerals in Haitian weathering profiies ... 

The isotope composition of biogenic and authigenic mineral precipitates from lake sediments can be used to infer changes in either temperature or the isotope composition of lake water. Knowledge of the factors that may have influenced the isotope composition of the lake water is essential for the interpretation of the precipitated phases (Leng and Marshall 2004). In many lakes the combined analysis of different types of authigenic components (precipitated calcite, ostracodes, bivalves, diatoms, etc.) may offer the possibility of obtaining seasonally specific information. 

Severmann S, Johnson CM, Beard BL, McManus J (2006) The effect of early diagenesis on the Fe isotope composition of porewaters and authigenic minerals in continental margin sediments, Geochim Cosmochim Acta 70 2006-2022... 

Coal contains detrital minerals that were deposited along with the plant material, and authigenic minerals that were formed during coalification. The abundance of mineral matter in coal varies considerably with its source, and is reported to range between 9.05 and 32.26 wt% (Valkovic 1983). Minerals found in coal include (Table 2) aluminosilicates, mainly clay minerals carbonates, such as, calcite, ankerite, siderite, and dolomite sulphides, mainly pyrite (FeS2) chlorides and silicates, principally quartz. Trace elements in coal are commonly associated with one or more of these minerals (see Table 2). 

Sedimentary rocks are composed of epigenetic minerals that have survived weathering and authigenic minerals formed in situ from low-temperature aqueous solution. Since authigenic minerals are formed from aqueous solution at low temperature, they are either amorphous or minute crystalline, and so the texture of sedimentary rocks is principally determined by the sizes and forms of epigenetic minerals. 

The problem is certainly more complex at conditions of low temperature and pressure where thermal energy is low and slight fluctuations in configurational energy can probably provide metastable crystallization as experienced often in the laboratory. However, we will retain the general principle that authigenic minerals will more closely represent equilibrium phases than will detrital minerals inherited from other geological cycles. 

Na and Ca to play equivalent roles in zeolites, as well as K, and if we consider A1 and Si as the major variables combined with K and Na in the phyllosilicates, we can adequately represent the phases in a (Ca-Na)-K-Al-Si system where H O is in excess in the fluid phase. If the system has four chemical variables and the natural assemblages are frequently found to contain four authigenic minerals, we must assume that most chemical variables are inert or extensive variables of the chemical system which controlled the crystallization of the zeolite-clay mineral containing sediments. ... 

When kdesorb is very slow (or even zero as when the compound is encapsulated in an authigenic mineral), [z]sorbed Ald[z]w so we can neglect the second term in the gradient driving transfer. In this case, we refer to the compound as experiencing sequestration. The parameter, (1 -fw), quantifies the extent of a compound s sequestration in a particular case of interest when we are justified to assume that the dissolved fraction is equal to the bioavailable fraction. Quantitative evaluation of desorb is taken up in Section 19.5. 

It is essential to understand the isotopic variability within authigenic minerals that form the basis of terrestrial paleoclimate records and between such samples that are isochronous within an outcrop of a stratigraphic formation. Except for variability studies in biogenic materials (teeth, bone, shells) (e.g., Kohn et al. 2002), we know of no paleoaltimetry studies that have examined this natural variability in authigenic or pedogenic proxy materials. Such variability studies should be conducted before any quantitative estimates of paleoelevation can be made. 

Chamberlain CP, Poage MA (2000) Reconstructing the paleotopography of mountain belts from the isotopic composition of authigenic minerals. Geology 28 115-118 Dickinson WR, Snyder WS (1979) Geometry of subducted slabs related to San Andreas transform. J Geology 87 609-627... 

Authigenic minerals minerals formed in situ such as carbonate fluoroapatite and pyrite. 

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