Geology Training Model Maker by grajohnt

Last crawled date: 3 years, 1 month ago

Introduction - Block Models
Training geology students how to understand the intersection of complicated geological surfaces and complicated topography can be challenging.
Simple concepts such as the "Rule of V's" can be taught with simple block models that allow students to see and understand how a dipping layer can make identifiable patterns on the Earth's surface.
Therefore, there is a long history of using wooden blocks to demonstrate everything from relatively complex structural geology to very simple cases.
These models can be purchased, or made by hand.
3D printing provides the opportunity to construct lesson-specific block models, and to create an inexpensive custom classroom set of models that can be integrated in a basic geology curriculum.
Instructions
Opening the Customizer allows you to upload a 100x100 pixel PNG image that is transformed from a greyscale image to a heightmap and placed as the upper layer of a block model.
Settings allow you to change the location, thickness, strike, and dip of the dipping layer, and generate a block model that suits your needs. A vertical scaling parameter is added to enable the adjustment from a greyscale image to something more resembling the topography that you input.
A few notes on using the Customizer
The greyscale images can either be real DEM data (like the Jotunheimen example file) or created in a drawing/paint program using grey gradient fills to represent topography. It is possible to invert the colors in the Customizer, so it doesn't matter whether you use darker or lighter colors to represent highs/lows.
Currently, the Customizer only supports strike angles from 0-90 degrees and dips from 0-90 degrees. To generate the two models included as examples, the greyscale image was simply rotated 180 degrees to enable the beds to dip the other way.
To preview how the dipping layer will fit with your topography, change the drop-down menu at the base of the Customizer to show "Remainder of model only". Note: Be sure to change this back to "Both parts" before clicking the "Create Thing" button to ensure that all necessary parts of the model are made by the script.
What is included here?
Besides the OpenSCAD code for the Customizer, there are several additional files included:
Two block models generated using the Customizer using the included files - these are the 'simplest case' of a valley and dipping bed aimed at teaching the "Rule of V's", similar to the simple wooden block models shown above:
Dipping_Upstream_Part1.stl
Dipping_Upstream_Part2.stl
Dipping_Downstream_Part1.stl
Dipping_Downstream_Part2.stl
Also included is a .zip archive containing several example PNGs that can be used immediately in the Customizer:
Valley_Heightfield_clean.png - used to generate the "Dipping_Downstream" model
Valley_Heightfield_clean_rotated.png - used to generate the "Dipping_Upstream" model
Valley_Heightfield_noisy.png - a version of the above with 3% gaussian noise added to simulate some topographic surface roughness
jotunheimen.png - an example of real DEM data in greyscale of the glacial valleys of the Jotunheimen area of Norway
How to print the models?
These models would typically require the use of a dual-extrusion printer, and can be printed in a variety of materials.
It is of course also possible to print the pieces individually and glue them together as well!
What next?
This Customizer has a limited strike/dip range, a limited resolution, and the ability to only add a single layer. The OpenSCAD file could be changed to increase the strike/dip range and to add more layers, and to possibly even add folded layers. However, the uploaded image resolution is constrained by Customizer to 100x100 pixels.
Improvements to the OpenSCAD model are strongly encouraged! This is meant to the be the start of a tool, not the end!
Good luck, and rock on!
Creators
This Customizer was the result of a conversation at the AGU Fall Meeting in 2016, and an eventual collaboration between Sinan Akciz (Cal State Fullerton) and John Thurmond - two people who have both taught geology courses at the undergraduate and graduate level and are keen users and abusers of new technology.