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If so, strain develops from a flattening fabric to a constrictional one for transpression (but never from constriction to flattening) and vice versa for transtension. The geometry of the strain ellipsoid is qualitatively shown in Fig. 6 for the spectrum of deformations discussed in this work. It should be noted how type D transpression and transtension separate deformations that produce oblate and prolate strain shapes, and how perfect constriction and flattening throughout deformation only occur along the base of the diagram (Wk = 0).

1993. Strain and kinematic analysis in general shear zones. Journal of Structural Geology, 15, 1-20. STERN,Y. , BATEMAN,P. , MORGAN, B. , NEWELL, M. E & PECK, D. L. 1981. Isotopic U-Pb Ages of Zircon from Granitoids of the Central Sierra Nevada, California. US Geological Survey Professional Paper, 1185. STOWELL, H. H. & HOOFER, R. J. 1990. Structural development of the western metamorphic belt adjacent to the Coast Plutonic Complex, southeastern Alaska: evidence from Holkham Bay. Tectonics, 9, 391-407.

Finite transpressional strain can be shown graphically in a Flinn diagram, in which the shape of the strain ellipsoid varies according to the amounts of simple shear along the zone and shortening or extension across it (see fig. 2 of Sanderson & Marchini (1984)). Because we have added an additional simple shear component to our analysis, a whole spectrum of Flinn diagrams is n e e d e d to show the interrelationship of all three strain factors. By way of example, in Fig. 3 two such diagrams (Fig.