sednorm--a program to calculate a normative ...

Computers & GeosciencesVol. 17, No. 9, pp. 1235-1253, 1991 Printed in Great Britain. All rights reserved

0098-3004/91 $3.00+ 0.00 Copyright © 1991PergamonPress plc

S E D N O R M - - A PROGRAM TO CALCULATE A NORMATIVE MINERALOGY FOR SEDIMENTARY ROCKS BASED ON CHEMICAL ANALYSES DAVID COHENand COLIN R. WARD Department of Applied Geology, University of New South Wales, P.O. Box I, Kensington, N.S.W. 2033, Australia (Received 18 December 1990; accepted 25 June 1991) Abstract--A method for calculating a normative mineral distribution, based on the major oxide

percentages, has been developed specifically for elastic sedimentary rocks and coal ash. Unlike previous methods, SEDNORM allows some variation in the method of normative calculation depending on the sample type and the range of chemical data available. Options available include changing the clay chemistry, including or excluding certain minerals and, in the absence of certain component analyses, allowing sufficient CO2 and H20 to be added to the system to form selected phases such as calcite until the associated components are exhausted. The method has proved successful for a range of sediment types including sandstones, shales, and carbonate rocks. Key Words: Sedimentary norm, Chemical analysis.

INTRODUCTION Quantitative determination of mineral abundances in sedimentary rocks by point-counting techniques may be a difficult and tedious task. In fine-grained rocks it is hindered by the similarity between the optical properties of quartz, kaolinite, feldspar, and quartzkaolinite or quartz-feldspar intergrowths, as well as the irresolvable mineralogy of many lithic fragments and matrix components. Staining of fine-grained materials by secondary iron-oxides or carbonates compounds the difficulties of optical identification. In addition to problems of identifying minerals by optical microscopy, sample inhomogeneity may require extensive point counting on a large number of thin-sections to ensure representivity. Whereas scanning electron microscopy can provide a definite identification and composition for individual submicron-sized particles, its use in determining bulk proportions of minerals in rock samples would be time-consuming and expensive. X-ray diffraction methods are capable of identifying the minerals present in a statistically representative sample of rock powder derived from a homogenized bulk sample, but variations in mineral crystallinity, mixed-layering in phyllosilicates and spectral interferences generally allow only limited use of XRD as a quantitative analytical method. The problems of mineral identification and sample representivity mentioned were encountered in a detailed study aimed at relating the mineralogy of sedimentary rocks associated with coal measures to their potential for ignition of methane gas from

frictional effects (Ward and others, 1990). An alternative to these methods--calculation of a normative mineral distribution--was considered, but previously published procedures for normative calculation did not represent adequately the mineralogy indicated by microscopic and X-ray diffraction data. As a result, a more comprehensive procedure was developed to assist in these and other quantitative petrological evaluations. The normative method was applied originally to igneous rocks in the form of the CIPW norm (Cross and others, 1902; Kelsey, 1965). This involves the systematic distribution of elements to particular minerals in a sequence derived from observed petrographic relationships. It assumes the presence of certain minerals in the rock, not necessarily identical to those actually present, and allows a quantitative "theoretical" mineralogy to be determined uniquely from the chemical analysis data. It is used widely in igneous rock classification and petrogenetic studies, but has had limited application to sedimentary rock materials (Hopson, 1964, used CIPW procedures on a suite of metamorphic rocks to determine the normative mineralogy of the original sediments and hence the source rocks from which they probably were derived). The mixture of minerals brought together by sedimentation is seldom likely to have had an opportunity to reach mineralogical equilibrium appropriate to the sediment's bulk composition, as might be expected with crystallized igneous material. Potassium, for example, can occur in significant amounts in both feldspars and their weathered products--~lay

1235

1236

D. Col-mr~and C. R. WARO

minerals. Calcium may exist in feldspars, various clays, and carbonates. Many of the more abundant sedimentary rock minerals, such as the clays, have a wide range of possible chemical compositions. This factor complicates the allocation of oxide components to particular phases in normative calculations which are intended to replicate the actual mineralogy of the rock concerned. A range of normative methods for sedimentary rocks and other materials are discussed in some detail by Milner (1962), Nicholls (1962), and Garrels and Mackenzie (1971). Normative methods for determining the mineral proportions in coal ash, using a simplified theoretical mineralogy, also have been applied by Pollack (1979), Given, Weldon, and Shur (1981), and Siansky (1985). As in the situation of the CIPW norm, the argillaceous norm of Nicholls (1962) was designed to provide a standardized mineral assemblage to allow general comparisons within sample suites. The results also can be used to calculate the actual mineral composition, provided additional data on mineral phases present are available. By comparison, the norm developed here is designed specifically to provide an approximation to the actual mineralogy of the rock, but may be used also in similar fashion to the classical normative approach which fixes the normative calculations for a given sample suite. The method of Nieholls (1962) assigns sulfur to an iron sulfide (FeS), or in situations where Fe203 is deficient, to a mixture of FeS and pyrite (FeS2). CO2 is allocated sequentially to calcite, magnesite, and then siderite, P205 to apatite and SO3 to gypsum. The allocation of components to the alumino-silicates commences with the allocation of iron and magnesium to end-member chlorites. The subsequent distribution of potassium, sodium, silica, and alumina into pyrophyilite, illite (muscovite), paragonite, kaolinite, quartz, or corundum is controlled by the ratio of AI:O3 to SiO2 after chlorite is formed. In the final calculation, pyrophyllite, illite, and paragonite are grouped as "illite". Nicholls (1962) identifies a number of problems with the argillaceous norm: (1) The presence of feldspar in the sample causes significant over-estimation or under-estimation of the phyllosilicate minerals in the norm, and (2) The variability in sedimentary montmorillonite composition causes problems with smectite calculation. A combined normative and thermodynamic method for determining the quantitative ideal equilibrium salt composition for natural waters evaporated to dryness has been developed by Bodine and Jones (1986). This method incorporates 63 possible normative salts and is designed specifically to assess the composition and origin of natural waters. This method would seem to be the most suitable for determining normative mineralogies of evaporite deposits.

The normative method developed in this paper provides an increased level of both complexity and flexibility to previously published procedures for sedimentary norm calculations. The results derived may be refined by supporting optical microscopy and XRD data. Although the norm adopts an "average" chemical composition for certain phases (such as the smectitic clays), it provides an initial and useful estimate of the mineralogy for a number of different sediment types. It should be noted that the method is designed for sedimentary rocks with the range of minerals defined here and is unsuitable for various chemical sediments including most evaporites, manganiferous deposits, and some iron ores. CHEMICAL ANALYSIS DATA The application of normative methods has been facilitated by the capacity for modern instrumental methods to provide rapid and precise chemical analyses of silicate rocks. This has opened up the possibility of developing extensive geochemical databases for materials ranging from sandstones to fly ash. One problem in developing a widely applicable system of normative calculation for sediments is the variation in the chemical components actually analyzed, from which the norm is to be derived. As well as the percentages of major oxides, some chemical analyses of sedimentary rocks include separate determinations of H20- (moisture lost on drying at 105°C) and H20 + (which includes loss of hydroxyl groups on heating the dry rock to 1050°C). Some analyses, including those of coal ash, report only the composition of the calcined material with no H20 data provided. If CO2 data are available, they may be in the form of total carbon or divided into the contributions from organic matter and carbonate minerals. Data may be available occasionally for some important minor elements such as sulfur and chlorine. The need to derive useful normative mineralogies from an incomplete original data set was taken into account in developing the present calculation procedure. CALCULATION OF THE SEDIMENTARY NORM The great bulk of most sediments generally is made up of an assemblage drawn from the list of minerals in Table 1. In order to give the program some flexibility and applicability to a wide range of sedimentary rock types, the following procedures have been adopted to handle the different components in the normative calculation process.

Phosphorus Phosphorus is assumed to occur only as apatite. Although a number of other phosphorus-bearing minerals such as goyazite-gorceixite and crandallite may exist in soils and some kaolinitic sediments

Normative mineralogy for sedimentary rocks Table 1. List of minerals and chemical formulae used in normative calculations Mineral

Formula

Quartz SiO2 Anatase TiO2 K-feldspar KAISi30s Plagioclase (Cao_lNat_o)Alt_2Si3_2O8 Muscovite KAI2(Si2Al)Olo(OH)2 Kaolinite AI2(Si205)(OH)4 lllite* K t.5A14(Si6.5All.5)O20(OH)4 Smectite* (Na,Ca)([Mg,Fe]AI3)[Sis020](OH)4 Calcite CaCO3 Dolomite CaMg(CO3)2 Magnesite MgCO3 Siderite FeCO 3 Apatite Cas(PO4)3(OH) Gypsum CaSO4-2H20 Pyrite FeS2 Hematite Fe203 Gibbsite AI(OH)3 Halite NaCI Water H20 *As well as interstratified clays involving these and related minerals. (Loughnan and Ward, 1970; Triplehorn and Bohor, 1986), and both apatite and goyazite-gorceixite may occur in coal (Ward, 1978), apatite is the dominant phosphate mineral in most sedimentary rock types.

Sulfur Sulfur is assumed to occur as either pyrite or gypsum. The options in the program allow the user to nominate to which of these two forms the sulfur should be allocated. In situations where there is an insufficient amount of iron to use all the sulfur in the formation of pyrite, the residual sulfur is allocated to gypsum (as sulfate). Conversely, if there is insufficient calcium (after the allocation of Ca to apatite) to consume all the sulfur with the formation of gypsum, the excess sulfur is allocated to pyrite.

Chlorine With the exception of evaporites (a type of sediment not considered specifically in this program), significant concentrations of chloride-rich minerals are rare in most sedimentary deposits. In this norm all chlorine is allocated to halite and the apatite is assumed to be chloride-free. If an excess of chlorine is present after allocating sodium to halite, extra sodium is added to form additional halite. The amount of sodium added in this way is reported along with the normative mineralogy. Similarly, chlorine is added to form halite if excess sodium is present after the clays or feldspar are formed (see next).

Carbonate minerals The carbonates used in the normative calculation are siderite, calcite, and magnesite. An estimate of the dolomite content can be derived by combination of the normative calcite and magnesite contents. If CO2 data are available from the chemical analysis, CO2 is

1237

assigned first to calcite, then to magnesite, and finally to siderite. Any excess iron after that calculation may be assigned to "other clays" and finally to hematite. If a carbon dioxide percentage is not given in the chemical analysis, the user may either assign all of the CaO and MgO to the respective carbonates (adding the necessary CO2 to the chemical data in the process) or excluded carbonate minerals completely from the calculation and allow any excess calcium or magnesium after allocation to the clays and feldspar to be reported as free oxide components.

Potassium illite /mica, and the feldspars Potassium in sediments may occur in illite, muscovite of K-feldspar, with the former being dominant in finer grained deposits and the matrix of coarser grained materials and the latter two components as free mineral grains or constituents of lithic fragments in coarser grained deposits. The user may nominate either muscovite or a high-K illite as the potassiumbearing layer silicate for the normative calculation, and also can nominate whether feldspar of any type (K-feldspar or plagioclase) is to be included in the normative calculation. If feldspar is included, the user may nominate the initial distribution of potassium between K-feldspar and muscovite or illite. Excess potassium remaining after these constituents are formed is assigned to feldspar. Calcium remaining after formation of apatite and gypsum is assigned to calcite or "other clay" ("smectite", see next) in an order specified by the user, and finally to the anorthite (CaA12Si2Os) form of plagioclase. Sodium left over from computation of halite and smectite similarly is assigned as aibite (NaAISi30~) to plagioclase.

Other clay minerals ("smectite") Clay minerals other than illite or kaolinite, including nonillite components of any interstratified clay minerals, are reported as "smectite" in the normative mineralogy. Such clays are difficult to work with in normative calculations because of the highly variable nature of the cations in their tetrahedral, octahedral, and exchangeable or interlayer sites. The water content also may vary greatly, especially among the smectite group where up to 15% adsorbed or nonstructural water ( H 2 0 - ) may be present as well as the structural OH (H 20 + ) groups. X-ray diffraction may be used to identify the clay minerals present in each particular instance (Brown and Brindley, 1961), but substantial additional work usually is required to establish the chemical composition of each individual clay component. Although chlorites are abundant in argillaceous sediments as detrital or authigenic minerals (Deer, Howie, and Zussman, 1966), they generally are absent in other sediments and soils, and therefore an alternative method for allocating iron, magnesium potassium, and sodium to the phyllosilicates to that of Nicholls (1962) and Garrels and Mackenzie (1971) has been

1238

D. Col-raNand C. R. WARD

adopted. A material described as "smectite" has been included with the composition: (Na,Ca) ([Mg,Fe]AI3) [Si8020] (OH) 4. This represents an iron-magnesium-bearing threelayer clay mineral without interlayer water (H20-), encompassing a hybrid of dehydrated montmorillonite, nontronite, vermiculite, and chlorite. It contains a somewhat higher proportion of exchangeable ions (Ca and Na in this instance) than the standard formula of Deer, Howie, and Zussman (1966), to allow for such elements being adsorbed onto illite or kaolinite and prevent the program from calculating an unduly high amount of smectite on the basis of the Ca and Na present. Inclusion of smectite in the normative calculation is optional, but if selected the user also can nominate the ratio of C a : N a in the ion-exchange layer and Mg:Fe in the octahedral layer, selecting between values of 0:1, 1: 1 and 1:0 in both situations. If this component is not selected, the Ca and Na are assigned to feldspar, along with the necessary A1 and Si, and the Fe and Mg to appropriate carbonate or oxide phases.

Kaolinite, gibbsite, and quartz The A! and Si left after calculation of the smectite percentage are assigned to kaolinite, and any remaining SiP2 is expressed as quartz. If AI~O3 rather than SiP2 is left after the kaolinite calculation, it is expressed in the normative mineralogy as the bauxite mineral gibbsite.

Water in normative calculations Where H20 + concentrations are not available, or where loss-on-ignition (LOI) data are given but the contributions from organic carbon, carbonate minerals, sulfur oxidation, and water (H20 + ) loss are unresolved, the user may allow the calculation process to add the H~O necessary to form hydrous mineral phases such as apatite and clays. The amount of H~O added in this situation is included subsequently with the summary of the normative mineralogy developed for each rock sample. If feldspars are excluded by the user from the normative calculation, as might be appropriate for shales and other fine-grained sediments, this procedure may be used to interpret a clay-based mineralogy by incorporating additional water (H20 + ) into the chemical components until the K20, CaO, and Na20 are fully accounted for as illite and smectite clays and the remaining A1203 and SiO2 as kaolinite. Further H20 + may be added to express the surplus Al~O3 as gibbsite.

Manganese Any manganese included in the chemical analysis data is assumed to be associated with iron (as pyrolysite inclusions) in hematite. This is consistent with the occurrence of Mn in many soils and sediments.

Some Mn may be present as a replacement of Fe in siderite or some of the clay minerals, but this is not accommodated by the normative calculation procedure.

Components not otherwise accounted for An excess of any element at the conclusion of the normative calculation is simply reported as the oxide. Such occurrences, however, are likely to be rare and in most situations the proportions involved are small. Elements such as sodium, calcium, or magnesium are unlikely to occur as oxides in sediments, but may occur as oxides or hydroxides in coal ash, representing residues of carboxylates and other organic phases in the original coal sample.

Calculation of volumetric percentages Estimates of mineralogy derived from normative calculation, similar to the analyses on which they are based, are expressed as percentages by mass of the sample in question. Mineral abundances determined by optical microscopy and point counting, on the other hand, usually are expressed as percentages by volume. To facilitate comparison to point-count data the program also reports the normative analysis on a volume basis, dividing the weight percent of each mineral by its density and recalculating the result to a sum of 100%.

Calculation sequence The sequence for allocation of oxides to the various minerals is summarized in Figure 1, and the individual options available to the user are described in Table 2. The sequence for calculating "smectite" and carbonate, as directed by the options selected, has

S-Pyr.e

fP-.ps.,,e

O,-.a,.e )

S-Gypsum

1o . . . . . . . .

f t Fe,Mg

o.-o=°..

,I

I

l [ I" "o'~ Fe-Siderite | I '/ I~ o I. .... ] ] CO2.Carbonates tt 4L 1 ' ®'

o

Smectite

K,Ca,Na-Feldspar ' Si-Quartz I AI- Gibbsite "~-"l Ti-Anatase Fe,Mn-Hematite, H20"Water I

J

K --Muscovite K-I te 1 AI,Si-Kaolinite ]

Figure 1. Outline of sequence for calculating sedimentary normative mineral composition.

1239

Normative mineralogy for sedimentary rocks Table 2. Options available within normative calculation sequence Option

Function

Value

Distribute K into muscovite Distribute K into illite Exclude feldspar from norm Include feldspar in norm Set distribution of K muscovite/illite:feldspar in ratio

1:0 1:1 0:1

Incorporate sulfur as sulfide (pyrite) Incorporate sulfur as sulfate (gypsum) (excess SO3is allocated to the alternate sulfur-bearing phase) Exclude smectite from norm Include smectite in norm Set ratio of Ca: Na in smectite in ratio

0:1 1:1 1:0 0:1 1:1 1:0

Set ratio of Mg:Fe in smectite in ratio 8

9 10

11

12

Distribute Mg initially into dolomite Distribute Mg initially into smectite Distribute Fe initially into siderite Distribute Fe initially into smectite Availability of COs data; COs data unavailable---excludecarbonates COs data unavailable---assignin Mg and Ca to carbonates (add COs to system) COs data available Fix H20 at the initial concentration Add HsO to system to produce daolinite if both SiO2and AlsO3 in excess at final stage or gibbsite if only AI203 in excess Add sufficientH20 to the system for the formation of hydrous phases such as clays Do not review options selected after each norm calculation Review options selected after each norm calculation

been simplified in these representations. The user may select the default option settings during creation of the input file. The default settings exclude muscovite, pyrite, and feldspar, set an intermediate composition for smectite, allocate calcium, magnesium, and iron to carbonates before smectite, and fix COs and H20 at the initial concentrations specified.

0 1 2 0 I 2 0 1

Line 3. Oxide concentrations in the order; SiO2, TiO2, A1203, Fe203, MnO, MgO, CaO, Na20, K20, P205, H20, COs, SO3, and CI The input data file may be created within SEDNORM using the question and answer option (including the selection of calculation options). Iron data may be specified as FeO or FesO3 and sulfur as S, SO3, or

THE PROGRAM The entire procedure for normative calculation is incorporated in a single executable program with associated input and message files. The SEDNORM program is written in standard F O R T R A N 77 and has been compiled under MS-FORTRAN 4.0 and IBM VS F O R T R A N version 2. Alternative procedures were tested using spreadsheets, but these provided insufficient flexibility in the method of calculation for different types of rock samples. As it is based to some extent on a fitting procedure, the program incorporates a series of questions and answers during the creation of the necessary input files.

Table 3. Composition of selected sampled used for normative calculations in Tables 4-6

Input

CaO

The input file (SEDNORM.INP) is free formatted, with the following set of input data lines repeated for each successive rock sample: Line 1. Sample Line 2. Options (1 to 12)

Analytical values (wt %) SiO2 TiOs A1203 Fe203 MnO

MgO NasO K20 PsO5 H20 COs SO3 C1

Carbonatealtered lithic siltstone Ward and o t h e r s (1990) 52.5 0.8 15.5 4.1 0.1 1.8 8.9 O.8 1.2 0.2 1.5 11.2 0.~ 0.0

Average sedimentary rock Garrels and N i c h o l l s Mackenzie (1962) (1971)

Bersham Mudstone

62.6 0.9 20.6 1.1 0.02 1.3 0.3 0.6 3.3 0.2 4.8 0.9 0.02 0.0

59.7 0.0 14.6 4.8 0.0 2.6 4.8 O.9 3.2 0.0 3.4 4.7 0.0 0.0

1240

D. Cot-m• and C. R. WARD

Table 4. Example input and output from SEDNORM for carbonate-altered lithic siltstone from Ward and others (1990). For details of options see Table 2

INPUT Carbonate-altered, lithic siltstone 0 1 2 1 1 1 1 0 0 2 1 0 52.48 0.75 15.47 4.08 0.09 1.84 8.92 0.79 1.19 0.18 1.54 11.23 0.04 0.0 OUTPUT (full mode) Carbonate-altered, lithic siltstone Analytical values (wt %) for oxide of: Mg Ca Na K P H C Step Si Ti AI Fe MB 1.9 9.0 0.9 1.2 0.2 1.6 11.4 53.2 0.8 15.7 4.1 0.0 !.9 8.8 0.8 1.2 0.0 1.6 ll.4 Apat 53.2 0.8 15.7 4.1 0.0 1.9 8.7 0.8 1.2 1.5 11.4 Gyp 53.2 0.8 15.7 4.1 1.9 0.0 0.8 1.2 1.5 4.5 Calc 53.2 0.8 15.7 4.1 0.0 0.8 1.2 1.5 2.4 Magn 53.2 0.8 15.7 4.1 0.8 1.2 1.5 0.0 Side 53.2 0.8 15.7 0.2 0.8 0.0 1.2 Musc 50.9 0.8 13.7 0.2 Feld 44.0 0.8 11.8 0.2 0.0 1.2 0.0 Kaol 30.2 0.8 0.0 0.2 Anat 30.2 0.0 0.2 Hm 30.2 0.0 Qtz 0.0 Normative mineral composition Optical point-count analysis Mineral % by mass % by volume % by volume Quartz 31.5 32.2 31 7 Feldspar 9.9 10.3 Kaolinite 26.7 27.4 26 (kaolinite + muscovite) Muscovite 5.0 4.9 Calcite 15.3 15.4 34 (total carbonates) Magnesite 3.8 4.2 Siderite 6.2 4.5 Apatite 0.4 0.4 2 (accessoryminerals) Hematite 0.3 0.1 Gibbsite O.1 O.1 Anatase 0.7 0.5

SO+, with the system converting the data to Fe203 and SO3 respectively. If option 12 (Table 2) is set at 1, all options may be reselected at the end of each successive norm calculation if required. A back-up of the previous input file (SEDNORM.BCK) is produced each time the main SEDNORM program is initiated.

Output Output from S E D N O R M may be presented at the user's selection in full or abbreviated form. The full

S 0.1 0.1 0.0

Cl 0.0 0.0

output gives residual oxide totals after each mineral is formed as well as the final mineral percentages (by weight and volume), whereas the abbreviated form simply gives the final mineral percentages. A series of three sets of rock data are presented in Table 3 and an example of a normative calculation is given in Table 4. This sample is a matrix supported quartz-carbonate sandstone from the Bowen Basin, Queensland, and contains quartz and lithic fragments in a clay/carbonate matrix with siderite nodules along some bedding planes (Ward and others, 1990).

lOO[

lOO

D

o o

D

%

I

2 8o

j.oL oo.

o o

eO o

•

- ~

20

r~ no 00

I

o

0

40 0

0

[]

0

o

oo

o

2O

0 0 i

0 A

20

i

40 60 Normative Quartz (~)

80

loo

01

0

i

i

i

i

i

10

20

30

40

60

i

i

eO 70

i

80

N~'matl~ Ouartz (%) B Figure 2. Comparison between normative quartz determined by SEDNORM and quartz content determined by (A) quantitative XRD and (B) petrological point-count methods, for range of sedimentary rocks from coalfields of eastern Australia (Ward and others, 1990).

i

i

90 100

Normative mineralogy for sedimentary rocks Table 5. Comparison of SEDNORM and argillaceous norm calculations (Nicholls, 1962) for Bersham Mudstone. Chemical composition is given in Table 3 Mineral

SEDNORM

Quartz Illite Kaolinite Smectite Calcite Magnesite Siderite Apatite Pyrite Hematite Anatase Excess of MgO

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normative model when compared to mineralogical analysis results of low temperature ash derived from the same coal sample.

Argillaceous norm (Nicholls,1962)

31.4 34.8 21.6 8.3 0.2 0.6 1.4 0.4 0.04 0.4 0.9 0.05%

TESTING OF METHOD

34.4 (quartz) 41.8 (illite) 12.6 (kaolinite) 5.2 (chlorite)

In the study by Ward and others (1990), it was demonstrated that the quartz content of samples is one of several critical factors in determining the capacity of sedimentary rocks to ignite methane in a surrounding atmosphere from fictional interactions. Quartz identified by point counting in these materials includes contributions from detrital quartz grains, secondary quartz (silica cement), and quartzose lithic fragments. Such identification, however, are only possible if the particles themselves are coarser than 5/am. Some quartz is also contained, but not able to be identified separately, in more aphanitic volcanic lithic fragments and fine-grained, quartz--clay intergrowths. Quartz contents were determined by semiquantitative X-ray diffraction methods, using the method of Ward (1977). This involved comparison of the intensity of the main quartz peak on the diffractograms to that of the main peak from a known mass of synthetic corundum spike. The normative method was applied to a wide selection of sedimentary rock samples in this project, and the results for quartz content are compared to those from point count and XRD methods in Figure 2. A reasonably close correlation was determined between the percentage of normative quartz and the

2.3 (siderite) 0.4 (apatite) 0.05(iron sulfide) 0.6 (hematite) 0.9 (anatase)

Options selected: exclude muscovite and include illite; exclude feldspar; include smectite with Ca: Na ratio 0:1 and Mg: Fe ratio 1:0; distribute Mg into smectite and Fe into siderite initially. The normative mineralogy also is compared to the point-count data obtained from optical microscope techniques. A reasonably close correlation exists in this sample between the quartz, feldspar, and minor components by normative and point-count methods. The carbonate mineral content, however, is higher in the point count data, a factor which also reduces the relative clay + muscovite percentage. As indicated, this may reflect problems in sample representivity for the single thin-section studied. Similar levels of variation were noted by Pollack (1979) from a more simplistic

Table 6. Variations in normative mineral assemblage for average sedimentary rock of Garrels and Mackenzie (1971) determined using different options in SEDNORM. Chemical composition is given in Table 3 Run

Options Include illite or muscovite Include feldspar Initial % K20 distribution Illite Feldspar Include smectite Ca: N a in smectitc Mg: Fe in smectite InitialM g distribution InitialFe distribution SEDNORM output Mineral

Quartz Feldspar Illite Kaolinite Smectite Calcite Magnesite Siderite Hematite H20 + Excess M g O Excess Na20 Excess K20 Excess C02

CAOIEO IT/9---E

1

2

3

4

5

6

7

Illi Yes

Illi Yes

Illi Yes

Illi Yes

llli Yes

Illi Yes

Illi Yes

Muse Yes

0 100

50 50

Yes I :I I:I Smec Smcc

Yes I :l I:I Smec Smec

100 0 Yes 1:1 1:! Smcc Smec

100 0 Yes 0:1 0:1 Smec Smec

100 0 Yes 1:0 1:0 Smec Smec

100 0 Yes --

100 0 No 1:1 I:1 ---

100 0 Yes

--

Dolo Side

8

Smec Smcc

~rcent ~ m ~ s

26.2 18.3 0.0

27.8 9.1 16.4

17.5

8.5

23.8 7.3

23.6 7.3

3.1

3.1

0.0 3.7 0.2 0.0

0.0 3.6 0.6 0.0

0.0

0.0

0.0

0.0

0.0

0.0

29.5 0.0 32.2 0.0 23.5 7.2 3.1 0.0 3.6 0.9 0.0 0.0 0.0 0.0

34.5 0.0 33.1 5.4 11.9 8.9 1.8 0.0 3.7 0.7 0.5 0.0 0.0 0.0

23.6 0.0 20.3 0.0 ~.5 3.1 0.0 8.0 0.0 0.6 1.8 0.9 1.2 0.4

35.3 7.8 33.0 7.2 0.0 8.8 1.8 0.0 5.0 1.0 0.0 0.0 0.0 0.0

35.3 7.8 33.0 7.2 0.0 8.8 1.8 0.0 5.0 1.0 0.0 0.0 0.0 0.0

34.3 0.0 27.0 0.0 23.5 7.2 3.1 0.0 3.6 1.3 0.5 0.0 0.1 0.0

1242

D. Col-raNand C. R. WARD

percentage of quartz indicated by point-count data. Samples which lie away from the line-of-best-fit generally contain high proportions of fine-grained, lithic fragments with mixtures of quartz, feldspar, and clays, or are sandstones with significant proportions of fine-grained, optically indeterminate matrix. The correlation between the normative quartz and the total quartz indicated by X-ray diffraction is high. The deviation in the trend at lower quartz contents is partially a function of the X-ray diffraction method. Some problems exist in the situation of poorly crystalline silica in cherty fragments, which has a lower X-ray diffraction effect than quartz. In addition a slight bias was noted in the standard calibrations, which reduces the calculated quartz content at low quartz levels. In a second example, the results from S E D N O R M are compared with an argillaceous norm from Nicholls (1962) applied to chemical data for a mudstone (Table 5). Using options designed to approximate the argillaceous norm method, the results in both situations are similar, although S E D N O R M produced more kaolinite and less illite than the argillaceous norm method. This is partly because of the elevated K contents in the illite formula used in the argillaceous norm. The "smectite" and "chlorite" contents of the respective methods are similar. The effects of altering the options for S E D N O R M are demonstrated in Table 6 for the average sedimentary rock of Garrels and Mackenzie (1971). In general, illite is formed at the expense of feldspar and kaolinite, whereas quartz, illite, and hematite are developed at the expense of smectite. For the purposes of comparing the normative mineralogy of a set of samples, a uniform set of options normally would be used.

Acknowledgments--This work was initiated as part of an assessment of frictional incendivity of Australian coal mine rocks, funded under the National Energy Research, Development and Demonstration Program (Project 1083) administered by the Commonwealth Department of Primary Industries and Energy. The authors wish to thank Drs. P. C. Rickwood and F. I. Roberts for critical review of the manuscript and Dr. P. K. Dutta for assistance in the project. REFERENCES

Bodine, M. W., and Jones, B. F., 1986, The salt norm: a quantitative chemical-mineralogical characterization

of natural waters: U.S. Geol. Survey Water Resources Investigations Rept. 86-4086, 135 p. Brown, G., and Brindley, G. W., 1961, The x-ray identification and crystal structure of clay minerals (2nd ed.): Mineralogical Soc., London, 544 p. Cross, W., Iddings, J. P., Pirsson, L. V., and Washington, H. S., 1902, A quantitative chemico-mineralogical classification and nomenclature of igneous rocks: Jour. Geology, v. 10, p. 555-690. Deer, W. A., Howie, R. A., and Zussman, J., 1966, An introduction to the rock forming minerals: Longman, London, 528 p. Garrels, R. M., and Mackenzie, F. T., 1971, Evolution of sedimentary rocks: W. W. Norton, New York, 397 p. Given, P. H., Weldon, D., and Shut, N., 1981, Investigation of the distribution of minerals in coals by normative analysis: Pennsylvania State Univ. Tech. Rept. 2L (Coal Research), p. 1-27. Hopson, C. A., 1964, The crystalline rocks of Howard and Montgomery Counties,/n The geology of Howard and Montgomery Counties: Maryland Geol. Survey, p. 27-215. Kelsey, C. H., 1965, Calculation of the CIPW norm: Mineralogical Magazine, v. 34, p. 276-282. Loughnan, F. C., and Ward, C. R., 1970, Gorceixitegoyazite in kaolinite rocks of the Sydney Basin: Jour. Proc. Royal Soc. New South Wales, v. 103, p. 77-80. Milner, H. B., 1962, Sedimentary petrography: vol. 1, methods in sedimentary petrography (4th ed.): George Allen & Unwin, London, 643 p. Nicholis, G. D., 1962, A scheme for recalculating the chemical analysis of argillaceous rocks for comparative purposes: American Mineralogist, v. 47, no. 1-2, p. 34-46. Pollack, S. S., 1979, Estimating mineral matter in coal from its major inorganic elements: Fuel, v. 58, p. 76-78. Slansky, J. M., 1985, Geochemistry of high temperature ashes and the sedimentary environment of the N.S.W. coals, Australia: Intern. Jour. Coal Geology, v. 5, p. 339-376. Triplehorn, D., and Bohor, B., 1986, Volcanic ash layers in coal: origin, distribution, composition and significance: Am. Chem. Soc. Symp. Series 301, Am. Chem. Soc., Washington, D.C., p. 90-98. Ward, C. R., 1977, Mineral matter in the HarrisburgSpringfield (No. 5) Coal Member of the Carbondale Formation, Illinois Basin: Illinois State Geol. Survey Circ. 498, 35 p. Ward, C. R., 1978, Mineral matter in Australian bituminous coals: Proc. Australasian Inst. Mining and Metallurgy, v. 267, p. 7-25. Ward, C. R., Cohen, D. R., Crouch, A., Panich, D., Schaller, S., and Dutta, P. K., 1990, Assessment of gas ignitability risk by frictional effects from coal mine rocks: End-of-Grant Rept., Nat. Energy Research, Development and Demonstration Program, Commonwealth Department of Primary Industries and Energy, Canberra, Project 1083, 233 p.

Normative mineralogy for sedimentary rocks APPENDIX

1

Program Listing P R O G R A M SEDNORM C C C C C

A P R O G R A M DESIGNED TO CALCULATE A M I ~ £ R A L O G I C A L N O R M COPYRIGHT

1990

D.R. COHEN,

FOR SEDIMENTARY ROCKS

UNIV. N.S.W.

D I M E N S I O N A(17,14),C(14),D(17),E(17),V(7),0(12),F(17),T(201 INTEGER H (20) C H A R A C T E R SAMPLE*60,OX (141 *5,MINA(171 *I5,MINB (17) *4,PAU*I, LIN*90 C H A R A C T E R ANSW* 1 COMMON C,O,T,H D A T A A(I, I) ,A(3, i) ,A(3,3) ,A(3, 9) ,A(3, Ii) ,A(4, i) ,A(4, 31 ,A(4, 91, .A(4, 11) ,A(5, 1) ,A(5, 3) ,A(5, 11) ,A(6, I) ,A(6, 3) ,A(6, 11) ,A(7,7), .A(7,121 ,A(8, 6) ,A(8, 12) ,A(9, 4) ,A(9, 12) ,A(10, 71 ,A(10, 10) ,A(10, 11), .A(11, 4) ,A(12,3) ,A(12, 11) ,A(13, 8) ,A(13,141 ,A(14, 4) ,A(14, 13), .A(15,7),A(15,11),A(15,13),A(16,11),A(17,2)/ 1.,.453,.385,.118, o.0425,.529,.323,.100,.048,.470,.398,.131,.608,.190,.043,.56,.44, o. 475, .525, . 62, .38, .558, .425, .016, 1., .654, .345, .393, .607, .222, .778, o.326,.209,.465,1.,1. / D A T A OX / 'Si','Ti','Al','Fe','Mn','Mg','Ca','Na', . 'K', 'P', 'H', 'C', 'S', 'Cl' / DATA M I N A / 'Quartz', 'Feldspar', 'Muscovite','Illite', 'Kaolinite', 'Smectite ', 'Calcite ', 'Magnesite ', 'Siderite ', 'Apatite ', 'Hematite', 'Gibbsite', 'Halite', 'Pyrite', 'Gypsum', 'H20+', 'Anatase' / D A T A M I N B /'Qtz', 'Feld', 'Musc', 'Illi', 'Kaol', 'Smec', 'Calc', 'Magn', 'Side', 'Apat', 'Hm', 'Gibb', 'Hal', 'Pyr', 'Gyp', 'H20+', 'Anat' / DATA E / 2 . 6 5 , 2 . 6 , 2 . 8 , 2 . 8 , 2 . 6 5 , 2 . 5 , 2 . 7 , 2 . 5 , 3 . 8 , 3 . 2 , 5 . 2 , 4 , 2 . 2 , 5 , .2.35,1,3.85 / OPEN (2, FILE- 'SEDNORM. MSG ', STATUS" 'OLD ') OPEN (3, FI LE- 'SEDNORM. OUT ', STATUS" 'UNKNOWN ') WRITE (*,2) READ (*,*)N IF (N.EQ.I) CALL FILMAK WRITE (*,3) READ (*, *) LL WRITE (*,4) READ (*, 111ANSW IF (N.EQ.I) GOTO 50 OPEN ( 1, FILE- 'SEDNORM. INP ') 50 OPEN (9, FILE" 'SEDNORM. BCK', STATUS- 'UNKNOWN' ) DO 14 L"1,1000 READ (1, 12,ERR-52,END-521LIN WRITE (9, 13) LIN 14 CONT INUE 52 REWIND (I) DO 1200 I-1,1000 60 DO 65 L-I,17 D (L) -0.0 65 CONTINUE A(2, I)-0.432 A(2,3)-0.366 A(2,71-0.201 A(6, 4)-0.054 A{6, 6)-0.030 A(6,71-0.036 A(6, 8)-0.039 DO 66 L-I,20 T(L)-0.0 S (L) -0 66 C O N T I N U E IF (K2.EQ.1) GOTO 75 READ (1, 10, END-1060) SAMPLE READ (1,*,ERR-1050) (O(K),K-l,12), (C(L),L-1,14) DO 70 L-1,14

1243

1244

70

72 75

76 90

C i00

150 151

153 154

160

165

166

D. COHEN and C. R. WARD T (8) -T (8) +C (L) CONTINUE DO 72 L-1,14 IF ((ANSW.EQ.'Y').OR. (ANSW.EQ.'y')) C(L)-C(L)/T(8)*I00 F (L) -C (L) CONTINUE GOTO 90 K2-0 DO 76 L-1,14 C (L) -F (L) CONTINUE IF (O(10).NE.2) C(12)-0 IF (O(11) .EQ.2) C(11)-0 IF (O(2).EQ.0) 0(3)-0 IF (LL.EQ.1) WRITE (3, 21) SAMPLE, (OX(JL),JL.,1,14), (C(L),L-l,14) STEP I. P205 INTO APATITE IF (C(10).EQ.0) GOTO 150 D (10)-C (i0)/A(10, i0) C (7)-C (7)-A (i0, 7)/A(10, i0) *C (i0) IF (0(11).NE.2) C(11)-C(11)-A(10,11)/A(10,10)*C(10) IF (C(7).LE.-0.1) T(12)-C(7)*(-I.0) IF (C(7).LE.-0.1) C(7)-0 C(10)-0 IF ((D[10).NE.0).AND.(LL.EQ.I)) WRITE (3,20)MINB(10), (C(L),L-I,14) STEP 2.1 S INTO PYRITE IF ((C(4).EQ.0).OR.(O(4).EQ.1)) GOTO 160 D (14)-D (14) +C(13)/A(14, 13) C (4)-C (4)-A(14, 4)/A(14, 13) *C (13) C(13)-0 IF (C(4).GE.0) GOTO 153 AFE-C (4) * (-1.0) C(4)--0 C (13)-C (13) +A(14, 13)/A(14, 4) *APE D (14)-D (14)-AFE/A (14, 4) IF (H(4).EQ.1) GOTO 154 IF ((D(14).NE.0).AND.(LL.EQ.1)) WRITE (3,20)MINB(14), (C(L),L-l,14) IF (C(13).GE.0.1) GOTO 160 GOTO 180 STEP 2.2 SO3 INTO GYPSUM IF (H(3).EQ.1) GOTO 166 IF (C(13)/A(15,13).GT.C(7)/A(15,7)} GOTO 165 D (15)-C (13)/A(15, 13) C (7)-C(7)-A(15,7)/A(15, 13) *C(13) IF (O(11) .NE.2) C (11) -C(11) -A(15, 11)/A(15, 13) *C(13) IF ((0(11) .NE.2) .AND. (C(11) .LT.0)) T(9)-T(9)+C(11)*(-1.0) IF ((O(11).NE.2).AND.(C(11).LT.0)) C(11)-0 C (13) =0 GOTO 166 D (15)-C (7)/A (15, 7) C (13) =C (13)-A(15, 13)/A(15,7) *C (7) IF (O(11).NE.2) C(11)-C(11)-A(15,11)/A(15,7)*C(7) C (7) -0 H(3)-I IF (C(13) .GE.0.1) GOTO 151 IF ((D(15).NE.0).AND.(LL.EQ.1)) WRITE (3,20)MINB(15), (C(L),L-I,14) STEP 3. C1 INTO HALITE

180 IF (C(14).EQ.0) GOTO 185 D(13)-C (14)/A(13,14) C (8)~C (8)-A(13, 8)/A(13, 14)*C(14) IF (C(8).LT.0) T(13)-C(8)*(-1.0) IF (C(8).LT.0) C(8)-0 C(14)-0 IF ((D(13).NE.0).AND.(LL.EQ.1)) WRITE (3,20)MZNB(13), (C(L),L-1,14) STEP 4.1 Mg, Na A N D Ca INTO "SMECTITE" 185 ZF (O(10) .~Q.0) GOTO 190 IF ((O(5).EQ.0).OR.(O(8).EQ.0))

GOTO 200

Normative mineralogy for sedimentary rocks IF (O(9).EQ.0) GOTO 300 ADJUST CATION RATIOS IN "SMECTITE" 190 IF IF IF IF IF IF IF

((O(5).E0.0).OR.(C(1).EQ.0)-OR-(C(3)-EQ.0)) ((C(11).EQ.0).AND.(0(ll).NE.2)) GOTO 197 (H(2).EQ.I) GOTO 200 (O(6).EQ.0) A(6,8)-A(6,8)*2 (O(6).EQ.2) A(6,7)-A(6,7)*2 (O(7).EQ.0) A(6,4)-A(6,4)*2 (O(7).EQ.2) A(6,6)-A(6,6)*2

GOTO 197

V (1)-C (I)/A(6, i) V(2)-C (3) Ia(6, 3) V(3) -C (4) IA(6, 4) V (4)-,C (6) IA(6,6) V(5)-C (7)/A(6, 7) V (6)..C (8)/A(6, 8) V(7)-C (11)/A(6, 11) IF (0(7).EQ.2) V(3)-I00000

"rF (O(7).E0.0) V(4)-100000 IF (O(6).E0.0) V(5)-100000 IF (O(6).EQ.2) V(6)-I00000 IF (O(11).EQ.2) V(7)-100000 BMIN-10000 DO 195 J-1,7 IF (V(J) .LT.BMIN) BMIN-V(J) IF (V(J).EQ.BMIN) KL-J CONTINUE 195 IF (KL.EQ.1) K-1 IF (KL.EQ.2) K-3 IF (KL.EQ.3) K-4 IF (KL.EQ.4) K-6 IF (KL.EQ.5) K-7 IF (KL.EQ.6) K-8 IF ((O(II).NE.2).AND.(KL.EQ.7)) K-11 D (6)-C (K)/A(6,K) IF (K.NE.I) C(I}-C(1)-A(6,1)/A(6, K)*C(K) IF (K.NE. 3) C (3)-C (3) -A (6, 3)/A (6, K) *C (K) IF ((0(7) .NE.2).AND. (K.NE.4)) C(4)-C(4)-A(6,4)/A(6,K)*C(K) IF ((O(7) .NE.0) .AND. (K.NE.6)) C(6)-C(6)-A(6,6)/A(6,K)*C(K) IF ((0(6) .NE.0) .AND. (K.NE.7)) C(7),.C(7)-A(6,7)/A(6,K)*C(K) IF ((O(6) .NE.2) .AND. (K.NE.8)) C(8)..C(8)-A(6,8)/A(6,K)*C(K) IF ( (O (11) .NE.2) .AND. (K.NE.II)) C(11)-C(11)-A(6, 11)/A(6,K) *C (K) C(K)-0 IF ((D(6).GT.0).AND.(LL.EQ.1)) WRITE (3,20)MINB(6), (C(L),L=l,14) 197 H(2)-I STEP 4.2 CO2 INTO CALCITE C C 200 IF (H(9).EQ.I) GOTO 300 IF (O(10).EQ.0) GOTO 212 IF (O(10).EQ.I) D(7)-C(7)/A(7,7) IF (O(10).EQ.I) GOTO 202 IF ((C(12).EQ.0).OR.(C(7).EQ.0)) GOTO 205 IF (C(12)/A(7,12).GT.C(7)/A(7,7)) GOTO 204 D(7)-C(12)/A(7, 12) C(7)-C(7)-A(7,7)/A(7, 12)*C(12) C (12)-0 GOTO 207 204 D (7)-C (7)/A(7,7) C(12)-C(12)-A(7,12)/A(7,7) *C (7) C(7)-0 202 IF ((D(7) .GT.0) .AND. (LL.EO.1)) WRITE (3,20) MINB(7), (C(L),L-l,14) 207 STEP 4.3 Excess CO2 INTO MAGNESITE C C 205 IF

(O(10).EQ.I) D($)-C(6)/A(8,6) IF (O(10).EQ.I) GOTO 210 IF ((C(6).EQ.0).OR.(C(12).EQ.0)) GOTO 212 IF (C(12)/A(8,12).GT.C(6)/A(8,6)) GOTO 208

1245

D.COHEN andC.R.

1246

208 210 211 212

C C

WARD

D(B)-C(12)/A(8,12) C(6)-C(6)-A(8,6)/A(8,12)*C(12) C(lZ)-0 GOT0 211 D(8)=C(6) /A(8,6) C(12)-C(12)-A~8,12)/A(8,6)*C(61 C(6)-0 IF ((D(B).NE.O).AND.(LL.EQ.l)) WRITE (3,20)MINB(8),(C(L),L=l,l4) IF ((0(5).EQ.O).OR.(H(9) .EQ.l)) GOT0 300 H(g)=1 IF (O(9).EQ.O) GOT0 300 GOT0 190 STEP 4.4 EXCESS CO2 INTO SIDERITE

300 IF (H(l) .EQ.l) GOT0 500 IF ((O(10).EQ.O).OR. (C(12).LE.0).OR.(C(4).EQ.0)) GOT0 350 IF (C(12)/A(9,12).GT.C(4)/A(9,4)) GOT0 320 D(9)-CC(12)/A(9,12) C(I)IC(I)-A(9,4)/A(9,12)*C(12) C(lZ)-0 GOT0 330 320 D(9)=C(4)/A(9,4) C(12)-C(12)-A(9,12)/A(9,4)*C(4) C(S)-0 330 IF ((D(9).NE.O).AND. (LL.EQ.l)) WRITE (3,20)MINB(9),(C(L),L=1,14) 350 IF ((0(5).EQ.O).OR.(0(9).EQ.1)) GOT0 500 H(l)=1 GOT0 190 C STEP 5 K INTO MUSCOVITE/SERICITE OR ILLITE C 500 N-3 IF (O(3l.GT.2) O(3)=2 IF (O(l).EQ.l) N-4 IF ((C(l).LE.O).OR.(C(3).LE.O)) GOT0 800 IF (C(9).LE.O) GOT0 600 FELK-(0(3)'0.5)*C(9) c(9)=(1-0(3)*0.5)*c(9) C V(l)-C(l)/A(N,l)

515

C

v(2)-C(3)/A(N,3) v(3)=c(9)/~(~,9) v(4~-100000 IF (O(ll).NE.2) V(4)-C(ll)/A(N,ll) BMIN-10000 DO 515 J-1,4 IF (V(J). LT.BIYIN)BMIN=V(J) IF (V(J).EQ.ENIN) KL=J CONTINUE IF (KL.EQ.l) K-l IF (KL.EQ.2) K=3 IF (KL.EQ.3) K-9 IF ((O(ll).NE.2).AND.(KL.EQ.4)) K-11 D(N)-C(K)/A(N,K) IF (K.NE.l) C(l)=C(l)-A(N,l)/A(N,K)*C(K) IF t~m.3) ~(~)-C(~)-A(N,~)/A(N,K~*~(K) IF (K.NFe.9)C(9)-C(9)-A(N,9)/A(N,K)*C(K) IF ((O(ll).NE.2).AND. (K.NE.ll)) C(ll)=C(ll)-A(N,ll)/A(N,K)*C(K) C (K)-0 C(9)-C(S)+FELK IF ((D(N).NE.OI.AND.(LL.EQ.l)) WRITE (3,20)MINB(N),(C(L),L=l,l4) STEP 6.1 EXCESS Ca, Na OR K INTO FELDSPAR

C

600 D(Z)-0 IF (0(2).EQ.O) GOT0 700

655

IF (C(7)+C(8)+C(g).LE.0.2) GOT0 700 IF (C(3) .LE.O.l) GOT0 900 N-7 IF ((C(l)/A(2,1).LT.C(3)/A(2,3)).AND.

Normative mineralogy for sedimentary rocks • (C(1)/A(2,1).LT.C(7)/A(2,7))) K=I IF ( (C (3)/A (2, 3) .LT.C (i)/A(2, I) ) .AND. • (C(3)/A(2,3) .LT.C(7)/A(2,7))) K-3 IF ( (C (7)/A(2,7) .LT.C (3)/A(2,3) ) .AND. • (C(7)/A(2,7) .LT.C(1)/A(2,1))) K=7 D (2)-D (2) +C (K)/A(2, K) IF (K.NE.I) C(1),.C(1)-A(2,1)/A(2,K)*C(K) IF (K.NE.3) C(3),.C(3)-A(2,3)/A(2,K)*C(K) IF (K.NE.7) C(7)..C(7)-A(2,7)/A(2,K)*C(K) C (K) -0 IF (N.EQ.8) GOTO 615 N-8 XCA-C (7) C (7) =C (8) +0.66"C (9) IF (C(7).EQ.0) GOTO 615 A(2, 1)-A(2,1) "1.59 A(2, 3) =A(2,3) *0.53 A ( 2 , 7 ) - A (2,7) *0.59 GOTO 655 615 IF ((O(10) .NE.1) .OR. (XCA.LE.0.1)) GOTO 616 H(5)-I D (7) =D (7) + X C A / A (7,7) 616 C ( 8 ) - 0

C(7)=0 C(9)=0

C C

C(6)-0 IF ((D(2) .NE.0) .AND. (LL.EQ.1)) WRITE (3,20)MINB(2), (C(L),L=l,14) IF (H(5).EQ.0) GOTO 700 IF ((XCA.GT.0.15) .AND. (LL.EQ.1)) WRITE (3,20)MINB(7), (C(L),L=l,14) STEP 7. EXCESS A1 INTO KAOLINITE 700 IF

((C(3) .LT.0.1) .AND. (C(1) .LT.0.1)) GOTO 800

IF ( (C (I)/A(5, i) .LT.C (3)/A(5,3) ) .AND. • (C(1)/A(5,1).LT.C(1I)/A(5,11))) K-1 IF ( (C (3)/A(5, 3) .LT.C (i)/A(5, I) ) .AND. . (C (3)/A(5, 3) .LT.C (11)/A(5, 11) ) ) K,.3 IF ( (C (11)/A(5, 11) .LT.C(3)/A(5, 3) ) .AND. • (C(11)/A(5,11).LT.C(1)/A(5,1))) K-11 D (5),.D (5) +C(K)/A(5,K) IF (K.NE.I) C(1)-C(1)-A(5,1)/A(5,K)*C(K) IF (K.NE.3) C(3)-C(3)-A(5,3)/A(5,K)*C(K) IF ((O(II).NE.2).AND. (K.NE.11)) C(II)-C(II)-A(5,11)/A(5,K)*C(K) C (K) -0 IF (O(II).EQ.0) GOTO 799 IF ((C(3) .LT.0.1).OR. (C(1) .LT.0.1)) GOTO 799 T (15)-T (15) +0.1 C(11)-C(11) +0.1 G O T O 700 799 C (11) -C (11) -T (15) IF ((D(5) .NE.0).AND. (LL.EQ.I)) WRITE (3,20)MINB(5), (C(L),L=I,14) STEP 3. Na INTO HALITE C C 800 IF (C(8).LE.0) GOTO 850 A C L - D (13 ) D (13)-D (13) +C (8)/A(13, 8) T (10)- (D (13)-ACL) *A(13, 14) C(8)-0 IF ((D(13) .NE.0) .AND. (LL.EQ.I)) WRITE (3,20)MINB(13), (C(L),L=I,14) STEP 8. EXCESS A1 INTO GIBBSITE C C 850 D (12)-C(3)/A(12,3) C (11)--C(11)-A(12, 11)/A(12,3) *C(3) IF (C(11).LT.0) T(15)-C(11)*(-1.0) IF (C(11).LT.0) T(9)-C(11)*(-1.0) IF (C(11).LT.0} C(11)-0 C (3) -0 IF ((D(12) .GE.0.1) .AND. (LL.EQ.1))WRITE(3,20)MINB(12), (C(L) ,L-l, 14) STEP 9 EXCESS Ti INTO ANATASE, Fe INTO HEMATITE (+ PYROLUSITE)

1247

1248

D. COHEN and C. R. WARD

Si INTO QUARTZ AND H20 INTO MOISTURE 900 D(17)-C (2) C(2)-0 IF ((D(17) .GE.0.1) .AND. (LL.EQ. 1) )WRITE (3,20)MINB(17), (C(L) ,L-l, 14) C (4)-C (4) +1.12"C (5) D(11)-C(4) C(4)-0 C(5)-0 I F ( ( D ( 1 1 ) . G E . 0 . 1 ) .AND. ( L L . E 0 . 1 ) ) W R I T E ( 3 , 2 0 ) M I N B ( 1 1 ) , (C(L) , L - l , 14) D(1)-C(1) C(1)=0 IF ((D(1) .GE.0.1).AND. (LL.EQ.I))WRITE(3,20)MINB(1), (C(L),L=I,14) IF (O(II).NE.2) D(16)-C(II) C(II)-.0 IF ((D(16) .GE.0.1).AND. (LL.EQ.I))WRITE(3,20)MINB(16), (C(L),L=I,14) FINAL OUTPUT TO FILE 'SEDNORM.OUT' 1100 DO 1101 L-1,17 T(6)-T(6)+D(L) T(7)-T(7)+D(L)/E(L) 1101 CONTINUE IF (O(12).EQ.1) WRITE (*,61)SAMPLE IF (LL.EQ.2) WRITE (3,61) SAMPLE IF (LL.EQ.I) WRITE (3,32) DO 1115 L-1,17 IF (D(L).LE.0.055) GOTO 1115 T(9)-T(9)+D(L)*A(L, II) WRITE (3,31)MINA(L),D(L)/T(6)*I00,D(L)/(E(L)*T(7))*I00 IF (O(12).EQ.I) WRITE (*,31) MINA(L),D(L)/T(6)*I00, .D(L)/(E(L)*T(7))*I00 1115 CONTINUE T(ll)-(D(7)*A(7,12)+D(8)*A(8,12)) IF ((O(II).EQ.I).AND.(T(15).GE.0.1)) WRITE (3,62)'H20',T(15),' ' IF ((O(II).EQ.2).AND.(T(9).GE.0.1)) WRITE (3,62)'H20',T(9),' ' IF ((O(10).EQ.1).AND.(T(ll).GE.0.1)) WRITE (3,62)'C02',T(11),' ' IF (T(10).GE.0.1) WRITE (3,62)'Cl ',T(10),' ' IF (T(12).GE.0.1) WRITE (3,62)'Ca ',T(12),' as oxide' IF (T(13).GE.0.1) WRITE (3,62)'Na ',T(13),' as oxide' DO 1118 L-1,14 IF (C(L).GE.0.05) WRITE (3,27)OX(L),C(L) 1118 CONTINUE IF (O(12).EQ.0) GOTO 1125 WRITE (*,48) READ (*,10)PAU 1125 CALL OPTIONS (K2,LL) IF (K2.EQ.1) GOTO 60 1200 CONTINUE GOTO 1060 1050 CALL GETMES(17) WRITE (*,48) READ (*,10)PAU 1060 WRITE (*,53) C 2 FORMAT (20(1),20X,'SEDNORM ',///,5X,'A program to calculate a ' ,'normative mineralogy for ',/,5X,'sedimentary rocks based on ', 'chemical analyses',///,5X,'c Copyright 1990 D.R. COHEN',/,SX, 'Dept. of Applied Geology, University of N.S.W.',/,5X, 'Kensington, N.S.W., 2033.',7(/),' Do you wish to .... ',//,10X, 'i Generate new input file',/,10X, '2 Use existing input file (SEDNORM.INP) > ',$) 3 FORMAT (20(/),' BEGIN EXECUTION OF SEDNORM ........ ',8(/), ' Do you require .... ',//,10X,'1 Full output',/,10X, .'2 Abbreviated output > ',$) 4 FORMAT (3(/)' Standardize the data... Y/N > ',$) i0 FORMAT (A60) 11 FORMAT (A1) 12 FORMAT (Ag0) 13 FORMAT (1X, Ag0)

Normative mineralogy for sedimentary rocks 20 FORMAT (2X, A4,3X, 14(F5.1)) 21 FORMAT (8(/),' Sample:',2X,A60,//,3OX,'Analytical values (Wt % ', 'of oxide)',//,1X,'Mineral',3X,14(IX, A4),/,' Formed ',//,9X, .14(F5.1),/) 27 FORMAT (/,10X,'Excess of ',AS,' ',F5.1,' %',13X,'as oxide') 31 FORMAT (10X,A15,3X, F6.1,5X, F6.1) 32 FORMAT (3(/),' Normative mineral composition:',// .,10X,'Mineral',10x,'Percent',/,27X,'by mass by volume',/) 33 FORMAT (1X, A60,/,17(1X, F5.1)) 48 FORMAT (//,' Return to continue ...... ') 51 FORMAT (/,A60,/) 53 FORMAT (15(/),' OUTPUT IN FILE... "SEDNORM.OUT"',/) 61 FORMAT (8(/),A60,2(/),' Normative mineral composition',// .,10X,'Minera1',10X,'Percent',/,27X,'by mass by volume',/) 62 FORMAT (/,4X,A3,' added in calculation ',F5.1,' %',A21) END

I00 I01 I0 30

SUBROUTINE GETMES (M) C H A R A C T E R MESS*75 D O 100 I-1,50 READ (2, 10,ERR-101)N,MESS IF (N.EQ.M) W R I T E (*,30)MESS CONTINUE REWIND (2) F O R M A T (I2, A75) F O R M A T (IX, A75) RETURN END

S U B R O U T I N E FI LMAK D I M E N S I O N OX (14) C H A R A C T E R INFILE* 16, MESS*75, SAMPLE* 60, ANSW* 1, ANSW2* i, OX*5, LIN* 90 CO~g4ON C(14) ,O(12) ,T(20) ,H(20) D A T A OX /'SiO2','TiO2','AI203', 'Fe203','MnO','MgO', 'CaO','Na20', • 'K20','P205','H20','C02','SO3','Cl' / OPEN (1, FILE- 'SEDNORM. INP ', STATUS- 'UNKNOWN' ) F1-1 F2-1 WRITE (*, 5) READ (*, *) IK IF (IK.EQ.2) GOTO 115 W R I T E (*, 4) READ (*, *) NSAM WRITE (*,8) READ (*, *) LL WRITE (*,9) READ (*, *) LK 115 DO 150 L-1,NSAM IF (IK.EQ.2) GOTO II0 W R I T E (*, 6)L READ (*, 30) SAMPLE IF (LL.EQ.1) F 1 - 2 . 5 IF (LL.EQ.3) F 1 - 0 . 8 3 3 IF (LL.EQ.1) 0X(13)-'S' IF (LL.EQ.3) 0X(13)-'S04' IF (LK.EQ.1) F2-0.45 IF (LK.EQ.1) OX(4)-'FeO' DO 130 K-1,14 W R I T E (*, 7) OX (K) READ (*, *)C (K) 130 C O N T I N U E GOTO 140 II0 W R I T E (*,I0) READ (*, 20) INFILE OPEN (4, FILE-INFILE, STATUS- 'OLD ') W R I T E (*,35)

1249

1250

D. COm~N and C. R. W A R D

140

54

55

59 60

READ (*, 45) A N S W H(3)-0 DO I00 I=i,200 IF (IK.EQ.I) GOTO 54 READ (4,30, END=210) SAMPLE READ (4,*,ERR=200) (C(J),J=I,14) W R I T E (*, 40) SAMPLE C(4)=C(4) *F2 C (13) =C (13) ~FI OX (4) ='Fe203' OX(13) ='S03' DO 55 N=I,14 WRITE (*,41)OX(N),C(N) CONTINUE IF (H(3).EQ.0) GOTO 59 IF ((ANSW.EQ.'Y') .OR. (ANSW.EQ.'y')) DO 60 LK=1,12 O (LK) =0 CONTINUE H(3)=I W R I T E (*,36) R E A D (*, 45) ANSW2 IF ((ANSW2.EQ.'N').OR.(ANSW2.EQ.'n')) O(1)-1

GOTO 82

GOTO

61

0(2)=0 O(3)=0 O(4)=0 O(5)=I O(6)=1 O(7)=1

0(8)=0

61

81 82 100 150 200 210

4 5 6 7 8 9 10

0(9)=0 O (10) =2 O(11)=i O(12)=0 G O T O 82 W R I T E (*,42) DO 81 J=1,12 IF ((O(2).EQ.0).AND.(J.EQ.3)) GOTO 81 IF ((0(5) .EQ.0) .AND. (J.EQ.6)) GOTO 81 IF ((O(5).EQ.0).AND.(J.EQ.7)) GOTO 81 IF ((0(5) .EQ.0) .AND. (J.EQ.8)) GOTO 81 IF ((O(5).EQ.0) .AND. (J.EQ.9)) GOTO 81 C A L L GETMES (J) WRITE (*,56) READ (*,*)O(J) CONTINUE W R I T E (1,62)SAMPLE, (O(KP),KP=I,12), (C(KH),KH=I,14) IF (IK.EQ.I) GOTO 150 CONTINUE CONTINUE G O T O 210 W R I T E (3, 70) SAMPLE R E W I N D (I) IF (IK.EQ.2) WRITE (3,75)INFILE, I-I IF (IK.EQ.I) W R I T E (3,75)' By Hand ',NSAM W R I T E (*,58) RETURN F O R M A T (//,' Enter number of samples > ',$) F O R M A T (//,' Do you wish to enter sample name and c h e m i c a l data', .//,10X, 'i By hand',/,10X, '2 F r o m a data file > ',$) F O R M A T (8 (/), ' Enter sample name for sample number ', 12, ' > ', $) F O R M A T (/,' Enter ',A6,' c o n c e n t r a t i o n > ',$) F O R M A T (/, ' Sulphur content p r e s e n t e d as;',//,20X, 'i S',/,20X, .'2 SO3',/,20X, '3 SO4 > ',$) F O R M A T (/, ' Iron content p r e s e n t e d as;',//,20X, 'I FeO',/,20X, .'2 Fe203 > ',$) F O R M A T (/,' Enter name of file with chentical data',//,15X,'Note:

Normative mineralogy for sedimentary rocks

20 30 35 36 40 41 42 45 56 58 62 70 75

100 102

.,' File format should be:',//,15X,'SAMPLE NAME (first sample)',/, .15X,'SiO2,TiO2,AI203,Fe203,MnO,MgO,CaO,Na20,K20, P205,H20,CO2,SO3 .,CI',/,15X,'SAMPLE NAME (second sample)',/,15X,'etc...',//) FORMAT (AI6) FORMAT (A60) FORMAT (/,' Do you wish to set the same options for all ' .,'samples? Y/N ',$) FORMAT (/,' Do you wish to set default options Y/N ',$) FORMAT (//,' Sample; ',A60,//,7X,'Oxide',6X .,' Wt %',/) FORMAT (6X, A6,4X, F6.2) FORMAT (/,' Option',28X,'Choices') FORMAT (AI) FORMAT (/,' Enter choice > ',$) FORMAT (20(/)) FORMAT (lX,A60,/,12(lX,F3.0),/,13(F6.2,1X)) FORMAT (///,' ERROR in sample: ',A60,///) FORMAT (///,' Input file: ',A16,//,1X, I2,2X,'samples',/) END

SUBROUTINE OPTIONS (K2,LL) COMMON C(14),0(12),T(20),H(20) CHARACTER ANSW* 1 M-6 IF (0(12).EQ.0) GOTO 130 WRITE (M, 55) IF (O(1).EQ.0) WRITE (M, 40)'1 ;','Muscovite' IF (O(1).EQ.1) WRITE (M, 40)'1 ;','Illite ' IF (0(2) .EQ.0) WRITE (M, 41)'2 ;','Exclude ' IF (O(2).EQ.1) WRITE (M, 41)'2 ;','Include ' IF ((O(1).EQ.1).AND.(O(2).EQ.1)) WRITE (M, 42)100-O(3),50 ,' Illite ',0(3)*50 IF ((O(1).EQ.0).AND.(O(2).EQ.1)) WRITE (M, 42)100-O(3),50 , 'Muscovite' ,0(3) *50 IF ((0(2) .EQ.0).AND. (0(3) .GT.0)) WRITE (M, 43) IF (O(4).EQ.0) WRITE (M, 44)'sulphide (Pyrite)' IF (0(4) .EQ.1) WRITE (M, 44) 'sulphate (Gypsum)' IF (0(5) .EQ.0) WRITE (M, 45)'5 ;','Exclude ' IF (O(5).EQ.1) WRITE (M, 45)'5 ;','Include ' IF ((0(5) .EQ.1).AND. (0(6) .EQ.0)) WRITE (M, 46)'0:1' IF ((O(5) .EQ.I) .AND. (O(6).EQ.1)) WRITE (M, 46)'1:1' IF ((O(5) .EQ.1) ,AND, (O(6).EQ.2)) WRITE (M, 46)'I:0' IF ((O(5) .EQ.I) .AND, (0(7) .EQ.0)) WRITE (M, 47)'0:I' IF ((O(5) .EQ.I) ,AND° (O(7).EQ.1)) WRITE (M, 47)'1:1' IF ((O(5) .EQ.I) rAND. (O(7).EQ.2)) WRITE (M, 47)'1:0' IF ((O(8) .EQ.0) ,AND, (O(5).EQ.1)) WRITE (M, 48)'Dolomite IF ((O(8) .EQ.I) ,AND. (O(5).EQ.1)) WRITE (M, 48)'"Smectite" IF ((O(9) .EQ.0) ,AND, (0(5) .EQ.I)) WRITE (M, 49) 'Siderite IF ((O(9) .EQ.1) .AND. (0(5) .EQ.1)) WRITE (M, 49) '"Smectite" IF (O(i0).EQ.0) WRITE (M, 50) IF (O(I0).EQ.1) WRITE (M, 51) IF (O(10).EQ.2) WRITE (M, 52) IF (O(ii).EQ.2) WRITE (M, 53) 'Variable IF (0 (II) .EQ.I) WRITE (M, 53) 'Partially variable' IF (0(Ii) .EQ.0) WRITE (M, 53) 'Fixed

C 130

149

IF ((M.EQ.3) .OR. (LL.EQ.2)) GOTO 149 M-3 GOTO 102 IF (O(12) .EQ.0) RETURN K2-1 DO 200 I-1,20 WRITE (*, 20) READ (*, 22, ERR-200) K IF ((K.EQ.0).AND.(I.EQ.I)) K2-0 IF (K.EQ.0) RETURN

1251

1252

D. Com~N and C. R. W^p.D

200 10 20 21 22 40 41 42 43 44 45 46 47 48 49 50 51 52 53 55

CALL GETMES (K) WRITE (*, 21) READ (*,*)L O(K)-L CONTINUE RETURN FORMAT (A1) FORMAT (/,' To modify options, enter option number ', '(return to recalculate) > ',$) FORMAT (/,' Enter choice > ',$) FORMAT (I2) FORMAT (2X, A3,' Include ',A10) FORMAT (2X, A3,Ag,' Feldspar') FORMAT (2X,'3 ; Initial K distrib. ',F4.0,' % into ',Ag,' and ', .F4.0,' % into Feldspar') FORMAT (TX,'Option error... Feldspar was excluded') FORMAT (2X,'4 ; S as ',A17) FORMAT (2X,A3,Ag,' "Smectite" ') F O R M A T (2X,'6 ; Ca:Na ratio ',AS) FORMAT (2X,'7 ; Mg:Fe ratio ',A5) FORMAT (2X,'8 ; Mg initially distributed into ',AIS) FORMAT (2X,'9 ; Fe initially distributed into ',AlS,) FORMAT (2X,'10; Exclude Carbonates') FORMAT (2X,'10; CO2 data unavailable; assign all Ca + Mg to ', .'Carbonates') FORMAT (2X,'10; Include Carbonates') FORMAT (2X,'11; H20 ',A18,5(/)) FORMAT (5(/),2X,'Options selected were ...',//) END

APPENDIX 2 ASCH Message File (SEDNORM.MSG)

3 4 4 5 5 6 6 7 7 8 8 9 9

I0 i0 I0 I0 ii Ii ii ii 12 12 12

Include muscovite or illite

(0) Muscovite

Include feldspar

(0) No

Initial K distribution between

(0) 1:0

(1) I11ite

(I) Yes (1) 1:1

(2) 0:1

(K is initially distributed into muscovite or illite, then excess K is distributed into feldspar) Sulphur as sulphide or sulphate

(0) Sulphlde

{1) Sulphate

Include montmorillonite

(0) No

(I)

Yes

Ratio of Ca:Na in montmorillonite

(0) 0:1

(1) 1:1

(2) 1:0

Ratio of Mg:Fe in montmorillonite

(0) 0:1

(1) 1:1

(2) 1:0

Initial distribution of Mg

(0) Dolomite

(i) Montmozillonite

Initial distributing of Fe

(0) Siderite

(1) Montmorillonite

CO2 data

(0) No C02 data available - exclude carbonates (1) No C02 data; assign all Mg and Ca to carbonates (2) CO2 data given

Fix H20 or adjust H20

(0) Fix (I) Adjust water to form kaolinite (2) Add water where necessary

Check options at end of each normative calculation and

(0) No

(1) Yes

Normative mineralogy~rsedimentaryrocks 12 15 15 15 17 17 17

permit modification WARNING

of options

One component

PROGRAM TERMINATED;

is now set to be less than 0%

Error in the input file selected

1253