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A linear programming and least squares computer method for solving petrologic mixing problems A linear programming and least squares computer method for solving petrologic mixing problems
Problems of petrologic mixing have been solved using a two-stage computer-based calculation. First, linear programming is used to obtain an approximate solution and to identify non-negative solution values. Then a conventional least squares calculation is performed using the analyses represented by non-negative solution values as input to yield an optimum set of solution values. The...
Authors
Thomas L. Wright, Patrick C. Doherty
Radiogenic heat production of contrasting magma series: Bearing on interpretation of heat flow Radiogenic heat production of contrasting magma series: Bearing on interpretation of heat flow
Variation in radiogenic heat production of rocks of diverse magma series (representative of calcic, calc-alkalic, alkali-calcic, and alkalic petrographic provinces on a worldwide basis) is better correlated with some form of magmatic differentiation index, rather than simply with potassium content alone as commonly supposed. The “lime-alkali” (Peacock) index generally gives the best...
Authors
Robert I. Tilling, David Gottfried, F. C. W. Dodge