TIME IN A DELTA

On what time scales does a delta evolve and how is that time preserved in startigraphy?

Here we use movies and images of peels taken from the eXperimental EarthScape facility (“Jurassic Tank”) at the National Center for Earth-surface Dynamics at St. Anthony Falls Laboratory to explore these questions via a number of exercises that measure the time scales of change in the actual experiment and compares that with the stratigraphic representation of those same time scales. The advantage of using experimental work in this case is that these experiments allow us to observe the actual mechanisms by which a delta evolves and ultimately is preserved as stratigraphy. It is true that a physical model such as this may be a simplistic representation of a more complex object or idea, but a model allows scientists to study natural processes in a condensed time frame. For instance, the formation of a delta in real time takes millions of years, while it may only take months to years to reproduce in a lab. We will also suggest a number of thought provoking questions that will help the student appreciate the value of doing experimental work in the Earth sciences and how we scale them to real world processes.