Sedimentary Structures

Here, we see some sedimentary structures.

These are tiny particles of mud, sand, and clay (or in the case of limestone, bodies of carbonate containing animals like mollusks and corals)that covered the ground, then got compacted and buried. Over the scale of thousands of years, these materials became rock.

Sedimentary Structures from Ted Rogers on Vimeo.

Mudstone is also an excellent preservation environment for fossils. Most types of organic matter tend to decay when oxygen is introduced. An anoxic environment, like several feet of mud, will keep oxygen consuming bacteria from using the organic matter as food.

Sandstone, which has larger particles, tends to be a poor preserver. Of course, there are some exceptions.

Next, we go on to the final exhibit of our tour.