ADIF,a FORTRAN IV program for solving the shallow-water equations

A computer program is documented, implementing a linear Alternating Direction Implicit (ADI) method for a limited-area finite difference integration of the shallow-water equations on a β plane. Arbitrarily large time-steps can be used with this method, which is stable unconditionally for the linearized equations. The method also is efficient computationally, as the difference equations are factored into one-dimensional operators which approximately reproduce the original set of equations, and this obviates the necessity for solving a matrix of large bandwidth. A line-printer plot contouring the height field is generated as part of the output. Program options include the determination at each time step of two of the integral invariants of the shallow-water equation. For long-term runs either a dissipative term is provided, or a nonlinear lateral eddy viscosity coefficient of a friction force.     

A FORTRAN IV program for the analysis of tectonic strain using deformed elliptical markers

A FORTRAN IV computer program is presented which provides an objective approach to tectonic-strain marker analysis. The algorithms are based on the “Theta-Curve” method and include a test (chi-square, goodness of fit) to check the validity of an initially random marker deformation model. Graphically represented values of confidence versus calculated tectonic-strain estimates, are produced for critical interpretation of results.Orientation data are not dependent on any preconceived reference directions such as cleavage or bedding. The method does assume, in its undeforming procedure, that the median value of the deformed marker-orientations is equivalent to the direction of maximum extension in the finite-strain ellipse.Optional line-printer graphics in separate subroutine form are included for producing the widely accepted diagrams and may be interfaced easily with other strain-analysis programs. A data-conversion program is appended to enable the use of preexisting data sets intended for the STRANE program of Dunnet and Siddans.     

MODES: A FORTRAN IV program to calculate modal analyses from raw point-count data

Program MODES is a FORTRAN IV program to calculate modal analyses of thin sections from raw data obtained by any normal point-counting technique. The program provides a table listing the modal analyses, quartz-feldspar-rock fragments (QFR) ratios, matrix-labiles-quartz (MLQ) ratios, ratios of plagioclase to total feldspar (P/F), ratios of volcanic lithic fragments to total lithic fragments (V/L), frequency, estimate, and confidence limits for each sample, and calculates the means and standard deviations for each component in a group of samples. It also prints a triangular diagram of the QFR or MLQ ratios. The program is useful where large numbers of modal analyses are determined because it requires no manual calculations, but it also has been determined useful when only a few samples are involved.     

AGCL,a FORTRAN IV program for agglomerative,nonhierarchical Q-mode classification of large data sets

This paper describes a FORTRAN IV computer program for an agglomerative, nonhierarchical classification scheme for large data sets. The program will accomodate 1000 items and 10 components. An example of geochemical data from Lake Erie is given.     

FORTRAN IV programs for processing routine electron microprobe data

A package of FORTRAN IV programs is used to process routine analyses of silicates, sulfides, oxides, and carbonates, following an empirical correction procedure. This approach has two important advantages; (1) computing costs are minimal, and (2) persons who lack experience with the probe or computer have been able to use the package effectively. Various options have been built into the package to give it the flexibility needed by a variety of users with differing objectives. The options include calculations of mole and weight-percent oxides or end members, construction of triangular diagrams, and use of a differing background correction for inhomogeneous minerals.     

A FORTRAN IV program for the classification of volcanic rocks using the irvine and baragar classification scheme

The Irvine and Baragar classification of volcanic rocks is based on chemical composition and uses for the most part existing and accepted terminology. Volcanic rocks are classified by use of silica and alumina contents, AMF values, normative color index, An content of plagioclase, ratio of normative Or: Ab: An, and normative olivine. The computer program for the classification of a volcanic rock using the Irvine and Baragar technique is written in FORTRAN IV, and is divided into three sections: (1) preparation of the chemical analysis—the analysis is adjusted for excess ferrous iron and corrected for volatiles: (2) calculation of a molecular norm (Niggli-Barth Norm): and (3) classification of the volcanic rock according to the Irvine and Baragar scheme The program output indicates the major chemical group (subalkaline or alkaline), the chemical series (tholeiitic, calc-alkaline, and sodic or potassic alkaline rocks), and the rock name as well as the plot used to determine each label. This program using the Irvine and Baragar technique realistically and reliably can name a volcanic rock.     

SOLVUS: A FORTRAN IV program to calculate solvi for binary isostructural crystalline solutions

SOLVUS is a FORTRAN IV program which utilizes experimental data to calculate a complete miscibility gap between two isostructural phases. This binodal curve and the corresponding spinodal curve are plotted on temperature-composition axes. A formulation of the excess Gibbs energy of mixing is required for the calculation. Three different formulations are used, that is the Margules, van Laar, and Scatchard-Hamer types, in alternate solvus calculations. The temperature dependences of parameters in the three formulations are fitted by least-squares regression to a hyperbolic tangent, given sufficient data, or else to a line. Sample calculations are presented for six systems, high albite-sanidine, halite-sylvite, calcite-siderite, pyrite-vaesite, oldhamite-niningerite, and oldhamite-alabandite.     

Coolit, a FORTRAN IV program that simulates fractional crystallization in the formation of layered intrusions

The use of the computer program COOLIT is described in this paper, the basis of the program is a temperature cooling function, mathematical crystallization using a ternary system with no solid solution and movement of material defined by Stokes Law within an intrusion. The data and initial conditions input to the program include coefficients for equations that define the ternary-phase system, crystal-phase information and physical parameters of the actual intrusion modeled. All of the initial conditions for the model may not be defined for a particular intrusion, some may have to be changed in order of obtain a better fit of the model's results to the observed features of the intrusion. By analysis different initial conditions, a greater insight into the formation of the layered igneous intrusions may be gained.     

An interactive FORTRAN 77 program using GKS graphics for 2.5 D modeling of gravity and magnetic data

An interactive 2.5 D gravity and magnetics modeling program has been written for an ICL PERQ 2 workstation using FORTRAN 77 and GKS graphics. All of the available hardware and software input devices are utilized through GKS to produce an easy-to-use menu-driven program. A large number of functions are controlled by the software in order than the user can concentrate on the model. A range of options also are provided for manipulating the observed anomaly. The use of FORTRAN 77 and GKS should make the program easily portable to other computer systems and graphics devices. The modular form of the program should facilitate readily further development including optimization and real time modeling, given a more powerful computer with high-speed graphics.     

Fuse: A FORTRAN V program for agglomerative fusion for minicomputers

FUSE is a program written in FORTRAN 77 for the agglomerative fusion or cluster analysis of 500 or more individuals on minicomputers. The use of direct-access I/O and a sorted queue enables reasonable execution times to be obtained with minimal memory requirements. Eight of the most popular agglomerative fusion strategies are available through the use of the Flexible Sorting formula; additional methods may be incorporated. Carbonate data of Imbrie and Purdie are used to test the merits of the technique generally, as well as provide discussion for a comparison of different strategies available. A simple space-distortion coefficient (SDC) is introduced to enable quantitative measurement of what previously has been an uncertain effect of application of the various clustering strategies. Measures of internal congruence, here termed fidelity measures, appear useful for comparing various strategies but fail as absolute measures of the value of a classification.     

A revised mathematical model and FORTRAN IV program to predict flow,bed topography,and grain size in open-channel bends

Modifications to the earlier model of Bridge (1976) are described using the original section headings. A new FORTRAN IV listing with full commentary is supplied, along with revised input requirements, and an example of the new line-printer output.     

ASSØCA: FORTRAN IV program for Williams and Lambert Association analysis with printed dendrograms

A general-purpose computer program implementing Williams and Lambert's method of association analysis is documented. The method embodies a hierarchical-divisive-monothetic strategy for the numerical classification of multiattribute, binary-coded data sets. The main user-controlled options permit a selection from among two different association coefficients and three termination criteria; employment of Yates' correction; presetting significance thresholds; discarding insignificant association coefficients; treatment of ambiguities in dividing attributes; and the transformation of quantitative measurements to a binary-coded form. A line-printer dendrogram plot displaying the final classification is generated as part of the output. Both normal and inverse association analysis can be performed.     

Filter: a FORTRAN IV program for separation of signal from background noise

This paper details a FORTRAN IV program for the separation of signal from assay data in the presence of background noise, using an optimum bilateral exponential smoothing model derived by Agterberg. This model takes into account a first order Markovian model of the type: C exp (?A∥k∥), for the autocorrelation function of data. The program works on data distributed along a line. However, extensions can be made for data distributed in two dimensions.     

A FORTRAN V program for a new classification technique: the g-mode central method

The G-mode central method is described. This method allows a large number of samples to be classified based on several variables. The classification method works without a priori knowledge of the taxonomic homogeneous units forming the statistical sample.     

BIOTURB: A FORTRAN program to simulate the effects of bioturbation on the vertical distribution of sediment

Bioturbation may have serious implications for preservation of original stratigraphic distribution of sediment. Thus, several methods have been developed to model the redistribution of sediment by bioturbation. The program BIOTURB provides a tool to compare and evaluate different models of bioturbation and their effects on sediment distribution. A flexible approach allowing changes in bioturbating fauna with time, fluctuation of sedimentation rate and sediment type deposited, selective sediment transport by organisms, both random and nonrandom mixing processes, and variation in intensity of mixing with depth was taken. This was achieved by using a transition matrix modeled after a bioturbating fauna in conjunction with a Monte Carlo procedure to govern the redistribution of sediment during mixing. The simulation model, FORTRAN program, and an example are described in detail.     

A fortran IV program for foraminiferid stratigraphic correlation and paleoenvironmental interpretation

A program compiled in FORTRAN IV and executed on an IBM 360/65 computer was designed to calculate simple arithmetic parameters. These parameters aid in the correlation of numerous sequences in which there are large numbers of samples from each sequence. The parameters are tabulated in such a way as to easily facilitate further plots on triangular and Fisher α diagrams, which elucidate paleoenvironmental changes and stratigraphic breaks. The Foraminifera were studied at species, benthonic superfamily and planktonic levels. The latter two distributions are shown on cumulative percentage diagrams.The restraints and suggested potential of the program are discussed, and its possible extension outlined with particular reference to industrial micropaleontology.A sequence of Albian (Gault) Clay from Wissant, Boulonnais, northern France is discussed in detail as an example of the use of this program. It is correlated with a similar sequence from Copt Point. Folkestone, southeastern England. Both sequences are adjacent to one another, being separated geographically by the English Channel. The fluctuations in abundance of selected foraminiferid groups in both sequences are directly correlative.