Exam technique #10

DIAGRAMS IN GEOLOGY

Diagrams are very important in Geology – from fieldwork to working with maps (which are of course sophisticated diagrams). They give a visual description of the information you are trying to put into words. In exams, they can save a lot of time. Drawing diagrams is a skill which it is well worth perfecting, Yet many candidates seem to treat diagrams as unimportant – and lose marks accordingly.

The keywords are:

  • neat
  • labels
  • arrows
  • scale
  • compass directions
  • title


Instructions given in the question.

Sketch

Draw a neat, well-drawn, freehand diagram, to scale, but without the frills.

  • it does NOT mean that the drawing can be scrappy and illegible!
  • marks will be awarded for precise labels, scale etc rather than the sketch itself;
  • it is useful to put a frame around the drawing – it keeps it to the right size;
  • when sketching clasts or grains, make them (and the scale) quite big, so that you do not have to draw too many of them;
  • use diagrams printed in other questions as a guide to the expected quality.

Draw

The drawing must be more precise, with correct measurements, for example when drawing sections, maps and fossils;

  • if it’s meant to be a straight line, use a ruler!
  • if an angle is involved, use a protractor!
  • if you are no good at drawing, don’t panic – the marks go for the measurements, labels, scale and other written information.

Caution – check the question to see if it says

  • draw a diagram – draw one, but it is acceptable to draw two;
  • draw diagrams – draw different views, for example of a fossil; if you draw only one diagram, you will lose marks

In WJEC exams, you may have to draw a diagram of a fossil specimen provided for the ‘practical’ exam. You must draw that particular specimen, not one which have seen in a text book.

Drawing diagrams in exams

Diagrams must be neat, clear, well-labelled and include a scale and title;

  • draw carefully, but you don’t have to be an artist!
  • draw simple line diagrams;
  • use the lines to highlight the important geological aspects and to show relationships and interpretations; for example, a line can be a bedding plane, or a fault, or a trilobite suture line etc;
  • put a frame around the drawing to keep it under control;
  • the head of a label arrow must touch the feature being identified;
  • use a ruler / protractor if appropriate;
  • use standard symbols and shading; for example, brick pattern for limestone, but keep shading to a minimum to save time.

Preparation and revision

Look at the diagrams in past papers to see the standard of drawing of the examiners!

Prepare labelled, scale diagrams of:

  • each type of fossil, from more than one viewpoint;
  • each type of rock texture, such as porphyritic, flow banding, vesicular, porpyroblastic, granular, gneissose, schistose, well rounded, poorly rounded, well sorted, poorly sorted;
  • each type of plate margin;
  • each type of volcano;
  • each type of sedimentary structure, especially the development of dune bedding.

Some of your prepared diagrams could be ‘copied’ from past papers.

Hint 1

Marks are for labels, annotations and scale rather than for the quality of artwork.

Hint 2

Remember –“ simple line diagrams with good labels”.