Recording structural information - Geological Field Techniques - page 191

This relationship was very rarely visible in the
fi eld, and had to await confi rmation following
study of thin-sections.

￿ Microfolding of S1 cleavage to form S2,
during heating and growth of metamorphic
minerals (e.g. albite, staurolite).
￿ Folding of S2 crenulation cleavage to form
numerous folds and a related, axial-planar
crenulation fabric, S3. The fl at-lying
orientation of the fold axial planes and S3
foliation imply this deformation phase
involved vertical thinning (and hence
horizontal extension).

A summary of the structural history was
proposed based on the following observations.

￿ Formation of fi rst tectonic fabric, a fi ne
cleavage. Evidence was too sparse to
determine whether this fabric formed during
folding of sedimentary layers, or by burial
and compaction.

8

8.4 Further reading

Davis, G. H. 2009. Structural Geology of Rocks and Regions , John
Wiley & Sons, 635 pp. [Clear, readable text on structural geology
and tectonics, with illustrations, explanation of techniques, and
experiments.]
McClay, K. R. 1991. The Mapping of Geological Structures , John Wiley
& Sons, 168 pp. [A small-format book focusing on how to map,
record and analyse geological structures.]
Park, R. G. 1997. Foundations of Structural Geology , Routledge, 216
pp. [Good, simple, introductory-level text.]
Ragan, D. 2009. Structural Geology: An Introduction to Geometrical
Techniques , Cambridge University Press, 624 pp. [This topic focuses
on geometrical analysis of structural problems, including the use of
stereographic projections.]
Ramsay, J. G. and Huber, M. I. 1984. The Techniques of Modern
Structural Geology Volume 1: Strain Analysis , Academic Press, 307
pp. [Rigorous and well-illustrated text covering all methods of strain
analysis.]
Ramsay, J. G. and Huber, M. I. 1987. The Techniques of Modern
Structural Geology Volume 2: Folds and Fractures , Academic Press,
391 pp. [Rigorous, well-illustrated text on the analysis of folds and
fractures (faults).]
Twiss, R. J. and Moores, E. M. 2007. Structural Geology , W. H.
Freeman & Co., 532 pp. [Attractive textbook with numerous
diagrams and illustrations, covering both theoretical and practical
aspects of structural geology.]
Van der Pluijm, B. and Marshak, S. 2004. Earth Structure - an
Introduction to Structural Geology and Tectonics , W. W. Norton &
Co., 672 pp. [Illustrated textbook that uses examples and analogies
effectively to explain structural geology and tectonics.]