alive and well - Geological Society of Australia

Cam Bryan’s GeojottingsA picture is worth a thousand wordsHow true! Except when your audience does not speakEnglish as their first language. I recall talking about thegeology of an area to a group of Chinese geologists andwhen the first slide came up I said, “A picture is worth a thousandwords.” That stopped the presentation for five minutes while theydiscussed what this phrase meant. I could only continue after acolleague had the wit to say ‘Confucius says, “a picture is wortha thousand words”’, whereupon the Chinese geologists all grinnedand nodded to one another — by which time I had forgotten whatthousand words had been saved by the picture.I was brought up to think that the camera cannot lie. One ofthe earliest uses of this phrase can be found in the Ohio newspaperThe Sandusky Register, February 1895: “He looked up fromthe proof at me and said: ‘Good Lord! Do I look like that?’ ‘Thecamera doesn’t lie about such things,’ I replied.” Nowadays welook at all photographs and wonder how many lies they aretelling us: what has been left out, added, changed. Photoshophas a lot to answer for! In Gilbert and Sullivan’s HMS Pinafore,Buttercup sings: “Things are seldom what they seem/ Skim milkmasquerades as cream ...” So we must beware — perhapsthe camera is lying, but on the other hand, perhaps we are notlooking closely enough.One example is the classic Hutton’s Unconformity on the Isleof Arran in Scotland. For many years the significance of a phreaticcalcrete hardpan between Lower Carboniferous sedimentaryrocks and steeply dipping Dalradian (Neoproterozoic–Cambrian)metamorphic rocks was not recognised. More recently the classiclocality has been reinterpreted as a double unconformity withthe hardpan being developed in Late Devonian times above theunconformity and disconformably overlain by the LowerCarboniferous rocks.A map is worth many thousand words. Whenever I look at amap I am reminded of the Earl of Warwick’s remarks about booksin Shaw’s play St Joan: “Now this is what I call workmanship.There is nothing on earth more exquisite than a bonny book, withwell-placed columns of rich black writing in beautiful borders,and illuminated pictures cunningly inset. But nowadays, insteadof looking at books, people read them.” Indeed, while a ‘bonny’map can be a joy to look at, it must also be read to extract allthe information recorded on it. But this also applies to photographsand diagrams. A picture ‘may be worth a thousand words’but it still has to be read, not just looked at.Maps, any map, but particularly geological maps, are surelywhere art and science come together: here we have the sciencein the units distinguished and the art in depicting them in amanner that enables the reader to easily understand what thegeologist is trying to get across.In a recent issue of TAG (TAG 162, March 2012, p. 30–32)David Branagan asked “Geological maps — have they had theirday?” I look forward to reading Letters to the Editor on this topic.For my part I am sure they will always be with us. As Davidemphasised, a geological map is a depiction of the geology asunderstood at the time it was prepared; it will change as more isknown about the geology, with new observations, new ideas andnew interpretations. The digitising of geological maps — as manyState geological surveys are doing — results in the ability to getmaps of any area of interest. Avoiding the irritation of having tojoin maps together (how many times has the area we wanted tolook at been on the boundary of two or more maps sheets?) isbut one advantage of the computer age in which we live. Anotheris the ability to zoom in on any area in a map. The iGeology app(reviewed in Tech Talk, this issue) illustrates these features withgeological maps of the UK.While geological maps often show lots of detail, there can beproblems with figures (line drawings and diagrams) that canshow too much detail. Quite often we crowd line drawings in aneffort to show everything! We can understand the figure, but thereader often cannot see the wood for the trees. This is particularlytrue with diagrams prepared for slides to accompany a talk. Withthe diagram on the screen only for a short time it is very hardfor the audience to take in everything at a glance. I recall aninternational conference where one member of the audience hadbrought a pair of binoculars to view some of the slides, whichwere so cluttered with detail and small printing that they werevirtually useless. PowerPoint visuals are a little better althoughthe tendency to add detail by sliding items in from left and rightas the presentation progresses can end up with a very confusingimage. The KISS principle is important for all such visual aids.There is a bit more latitude in diagrams prepared forpublication as the reader can pore over them at leisure and comeback to them when in doubt. Nevertheless, the diagram thatmeans everything to the author may not be so clear to the reader.A picture may indeed be worth a thousand words, but unlessthe details of the image are chosen as carefully as you wouldchoose a thousand words, it may be better to show (and say)nothing!TAG September 2012| 43