Pumpkin Patch near Anza-Borrego


Image: ExploreCalifornia.pics

Just outside of Ocotillo Wells, near Anza-Borrego Desert State Park, sits a geologic phenomenon called the Pumpkin Patch due to the rocks’ size, shape and distribution in the field.

How did these rocks form? Why are the rocks a consistent shape and size and how do natural processes continue to expose more of these rocks over the years?

These rocks are a unique geologic feature called concretions, which form when layers of sediment build up around a nucleus like a pebble or a shell. Erosion from wind and water expose these rocks. Similarly, erosion shapes the concretions. Eventually, the same forces that expose the concretions will wear away each of these uniquely shaped rocks.


Desert USA: Concretions

Paleontological Research Institution: Concretions

The Adventure Portal: The Pumpkin Patch

Earth and Space Science

More Activities & Resources:

Why do some spiders weave spiral orbs while others weave, tangled or tunneled webs?
How can a scuba tank carry enough air for a diver for such a long period of time?
What causes the Catalina eddy, and when does it typically appear?

The Fleet Science Center invites you to connect to the power of science through FLEETtv!