Drawing Geological Structures

PREFACE

Drawing is not one of my strengths. My firs attempts at representing rock structures from the fiel on paper ended in disaster, both with regard to the graphic quality as well as the information content of the drawings. It took a long time for me to be able to draw structures halfway precisely and increase their recognition value; to use perspective; to learn to draw symbolically; and to compose larger outcrop drawings and block diagrams.

In my early field days, Gerhard Voll accompanied me as role model and companion who showed me, by way of his own geologically and artistically sophisticated drawings, how it’s done. In later field and drawing classes, many of my students were at a higher level from the start than I was when I began. Fortunately, talent is not required for geological drawing—only the willingness to observe and a little practice to acquire the basic rules for drawing geological structures. A special merit of drawing is that it requires us to look closely.

The click of the camera cannot do this. While we are drawing, we must already geologically assess what we are drawing. Therefore, not just the drawing, but also the path to it, is relevant. Graphical representation—manual drawing—is nothing old-fashioned and
superfluous or just a nice pastime. In the digital age, it is urgently needed, because it teaches us to observe and reflect and it leads to concentration and mindfulness. This book is about drawing as a language—a language in which geological information can be conveyed precisely and straightforwardly.

Contrary to art, a geological drawing is not open for a personal point of view. It is intended to capture a structure’s geological message and represent it so that it can be correctly interpreted by the observer. Furthermore, drawings can be used to effectively and quickly store the geological information contained within a structure. Conversely, drawings give us quick and easy access to information while also providing us with a highly informative archive.

This book is an exercise book. Nevertheless, it contains only a few, exemplary exercises. This is because, apart from the basics, geological drawing can only be learned to a limited extent with the help of dry training. One learns by observing structures in rocks and under the microscope, and by drawing them directly. For effective practice, one must go out into the field or to the microscope, or, if necessary, search for suitable samples in the geological collection.

This is the only way to observe structures in different ways—by walking around the rocks in an outcrop, looking at them up close and from far away,using a hammer and chisel to expose important surfaces, or by varying magnifica tions and other conditions under the microscope.This book is intended to stimulate such practice and be a companion that exemplifies by means of different rocks and structures, the many possibilities of drawing and its development stages from start to completion. A further focus of this book is how drawings can be optimally composed with regard to high information content and quick access to this information. In addition, this book is intended to serve as an encouragement to apply drawing in daily practical work—including areas beyond those discussed here!

This is also important: The geological sign language presented in this book is not an unalterable set of rules. Like every language, it is flexible and open to change. Although the foundation of drawing may stay the same, every person can interpret the rules in their own way, develop new schema of drawing, and arrive at their own “dialect.” For didactic reasons, many drawings have been revised or completely redesigned for this book. Several drawings, however, were taken directly from my field books or microscopy notes—with thick lines, mistakes, and corrections.

They are unclean and don’t always follow the rules, but reflect the real situation when drawing is a daily work instrument. Whenever possible, these drawings are depicted
in their original scale, or at least not greatly reduced. They shall not be made prettier than they are. Even though it is alright and good (and even necessary for certain purposes) to make clean and aesthetic drawings, the hasty and coarse line is the normality when drawing from nature. The quick, rudimentary sketch is the colloquial language of geological scientific work. This is also covered in this book.

The foundations of this book arose mainly through my own practical work in the fiel and at the microscope, but also through numerous microscopy and several drawing courses for which I could occasionally, despite crammed curricula,
fin the time. The interest of the students as well as the colleagues was always motivating. Thank you for that. In addition, my thanks go to Tom Blenkinsop, who encouraged me to write this book; Herbert Voßmerbäumer, who, as reviewer and with his positive attitude, helped to get the book started; as well quite a few anonymous reviewers who spoke generously and favorably about the project. The book manuscript clearly benefite from the careful inspection by Uwe Altenberger, Annette Huth, and Matthias Nega. I deeply thank you for this. Last but not least, I would like to thank the Wiley-Blackwell staff, who have accompanied the book, with great patience, through its different stages of development over the years—especially Ian Francis, Kelvin Matthews, and Delia Sandford, who accepted, with friendly serenity,
my numerous excuses for why the manuscript was still not finished and Sanjith Udayakumar, Ramprasad Jayakumar and Arabella Talbot, who supervised the book in the production phase.
Jörn H. Kruhl Munich, January 2017 x

Drawing Geological Structures