Visualising Geology in Three Dimensions

by

Bill Sowerbutts and Catherine Hunt, University of Manchester

The ability to visualise in three-dimensions is an essential skill for the interpretation of a great deal of geological data. This module, which is intended primarily for first-year undergraduates, deals with various aspects of visualising in three dimensions. The module has two main aims.

1. To enable students to take various types of spatial geological data and from them visualise geology in three dimensions.

2. To serve as a vehicle for introducing and reinforcing several basic concepts that geologists need to be aware of when interpreting geology.

The module occupies just under 8Mb, and comprises seven units, three of which are subdivided into smaller units. They are accessed from this menu.

Unit 1. Basic concepts

A simple outline of what is meant by 3d, 2D and 1D. An introduction to 3d visualisation by means of spatial reasoning tests. Essentially a non-geological introduction but nevertheless using examples that have some relevance to geology (e.g. rotated shapes, sections, intersections).

Unit 2. Undeformed rocks in 3d

This unit is restricted to igneous and sedimentary bodies (metamorphic rocks are covered in the Unit 3). The Background unit includes a brief summary of dip and strike, since the terms dip and strike are used freely in describing the geometry of particular features.

A page from the unit showing the 3d shapes of undeformed rocks

Unit 3. Deformed rocks in 3d

An introduction to fault and fold geometries, including some basic terminology (e.g. antiform, synform, hinge and limbs for folds, hangingwall and footwall for faults). How faults and folds end, together with some possible relationships between faults and folds. The last part in this unit deals with the shapes of metamorphic bodies.

This page details fault terminology

Unit 4.Cross-sections

A simple introduction to how sections are produced from map and other data. Scales and vertical exaggeration. Age relationships as seen on cross-sections. A brief introduction to seismic sections as a form of cross-section.

Various type of user interaction are employed; in this case users enter a numerical value

Unit 5.Block diagrams

Block diagrams of composite geological rock forms and structures from different viewpoints, including faulted and folded strata. Exercises entail extending and extrapolating visible geology.

Unit 6. 3d geology from 2D data

Visualising 3d features from 2D representations. This unit focuses on contour maps but also includes mention of parallel sections and fence diagrams.

The three dimensional surface forms depicted by contour maps are covered in the 3d geology from 2D data unit

Unit 7. Wells and well logs

The use of point and line data. Dipmeter and gamma ray logs provide simple exercises that involve interpreting aspects of geology from available data.

User interaction in this well log example involves dragging labels to identify views from different directions

Also included is a short assessment, which allows users to test their understanding of the material covered in the module.

Running the software

Once you have started a unit, navigation through the pages is by means of buttons. The majority of the navigation buttons appear along the base of the screen.

There is a help section where the purpose of the different buttons is explained, and a glossary containing definitions of words and concepts related to three-dimensional aspects of geology.

Other Modules Available