Geoscience Reference
In-Depth Information
10
Figure 10.20
An example layout for a fair copy map. (Map of Angela L. Coe, The Open University, UK.)
Mudstone Group), or a code of letters and numbers based
on the age of the unit (e.g. K6 is a code for the Cretaceous
White Chalk Subgroup in the UK; Obe stands for the
Ordovician Bald Eagle Formation in Pennsylvania, USA).
These may conform to formal lithostratigraphic schemes, or
you may need to devise your own. Place several labels
within a large outcrop; link labels to small outcrops with a
leader line. Lettering can be done using transfers (costly) or
stencils, printed neatly by hand or typed directly onto
digital maps.
Add suffi cient structural symbols (bedding, foliation,
lineation and folds) to allow the stratigraphy and structure
to be determined. Mark only the dip or plunge angle by the
symbol, not the strike bearing (because the line itself
defi nes the strike azimuth). Make sure that symbol types
and sizes are consistent (Appendix A10, Figure A10.3),
both across the map and in the explanatory key.
Clarity is essential, so make sure that symbols are neat and
not congested. Omit locality and sample numbers, and
