Noddy 3D Modelling

This page houses links to the Noddy 3D Geological and Geophysical Modelling System. The Noddy modelling system allows you to rapidly build complex 3D geological models and calculate the resulting gravity and magnetic fields. It’s primary use in in teaching, although of course it does allow you to try out simply geological scenarios as well.

How Noddy Works:

In order to characterise the complex three dimensional structures that often cause geophysical anomalies it is necessary to have some understanding of the structural history of an area. The basis for this program is the ability to construct a complex geological history as a succession of relatively simple structural, sedimentary and igneous events. Each geological history is defined as a sequence of kinematic events, and each event is defined by a set of orientation, position and scaling parameters. The structural modelling used in this program were first written by M Jessell as part of an MSc at Imperial College, London University, in 1981, as an interactive map creation package, and later commercialised by www.encom.com.au after geophysical modelling capabilities and many other changes were made as part of an industry funded AMIRA collaboration between Monash University and the CSIRO. (Encom does not and will not support the version available here, so please don’t ask them).

The program consists of introducing geoelogical events to effect an infinite volume of rock. The displacement equations are defined explicitly or implicitly with respect to flat planes, so that the curvature of the earth is ignored. The displacement equations within this program are all unary, that is there is a one to one mapping of all points before and after each deformation event. The user is protected from these equations and is instead asked to describe the deformation in “normal” structural terms, such as strike and dip.

Manual (PDF)