Onward to creating your own lithofacies map from data gathered in Montana!
In this exercise, you will create a lithofacies map and determine the environment present in the state of Montana during the Cambrian Period of geologic time. We’re focusing on the environment as it was about 500 Ma. This was a mixed siliciclastic/carbonate environment. As you’re determining the facies separation and naming of the environments you’ll use the Mixed Siliciclastic/Carbonate diagram from above. ***Note, fine sandstone (Fss) and siltstone are grouped together in this analysis. Save the map image (below) to your computer and use simple drawing tools to help create the lithofacies map similar to the example. There are many different types of drawing tools available and you’re welcome to use anything that you’re familiar with to get the job done. You’ll upload your completed lithofacies map using the “Submit” icon at the top of this page. Search online for a paleogeographic map from the Cambrian that shows the paleogeography at about 500 Ma. You’ll need that for comparative analysis in the questions that follow in the next assignment.
Here are the steps to complete:
- Download the map below to your computer.
- Annotate the map using simple drawing tools to create a lithofacies map.
- Label the environments: fluvial (terrestrial); beach; offshore; open shelf (see the mixed siliciclastic/carbonate environment above).
- Save the map to your computer.
- Find a paleogeographic map from the Cambrian that shows the paleogeography of this same region at about 500 Ma. Two good options are here
Links to an external site. and here,
Links to an external site.. - Answer the question, In a few sentences, compare the lithofacies map that you created with the paleogeographic map from the Cambrian time period, about 500 Ma. How well do the two compare? Are there similarities, differences? What could be the cause of the differences? I attached a example below.