Choose Learning Type ▼

Nature’s Chalk

Activity

Discover the Secret of Soft Limestone!

Did you know that the limestone in Pease Park is so soft in some places that you can use it like chalk? Your mission: Find a piece of limestone and test it out! Can you draw or write on a rough surface, like a sidewalk or a rock, with your limestone? What happens when you rub it on a rough surface? Does it leave a streak or crumble apart?

Science Seed

Limestone is a soft sedimentary rock primarily made of calcium carbonate (CaCO₃), the same mineral found in traditional chalk. In fact, some types of limestone, like the soft limestone in parts of Texas, can be used just like chalk! When rubbed against a rough surface, soft limestone leaves a white streak, just like regular chalk. However, not all limestone is soft—some types are much harder and won’t leave a mark. The difference between soft and hard limestone depends on how the rock was formed and how much pressure it has been under over time. Over millions of years, limestone forms when tiny bits of shells, sand, and other materials settle and press together. As rain and wind erode the rock, the softer parts break down more quickly, while the harder parts may stay in place. The limestone in Pease Park shows how time and the environment shape the rock’s texture and form, turning it into the unique chalk-like stones you can find today!

move to the next activity

earn Badges

Badges can be earned through hands-on experiences within each of the 16 branches of science, or “Science Slices.” You can earn a badge in each branch of science by doing four activities in these categories. We also encourage participants to keep a Nature Journal to record their memories, and to express themselves creatively through writing or drawing after each activity. We recommend that each child (and parent if they’d like) write or draw in a journal after each activity, with expectations of your children that match their age (the goal is self-expression, not perfection).

Explore Pease Park Conservancy

The Ecologist School Pocket Guide: Pease Park Edition is a collaboration between Families in Nature and Pease Park Conservancy as an effort to help our community learn more about the ecosystem and history of Pease Park, while getting outside into nature together! This booklet has 64 lessons across 16 different branches of science to help you play, learn and volunteer in the park as a family!

Each branch of science corresponds with a matching badge featured in the top right corner of every activity. Complete all 4 activities in a science slice and you are eligible to earn that badge.

Circle of Sciences

Our hands-on activities span across 16 different branches of science! Each Science Slice is broken into 8 learning categories: S.T.E.A.M., Volunteerism, Outdoor Skills and Leadership Development. Our activities are designed to be enjoyed by all ages.

join Families in Nature

It is our vision to inspire all families to fall in love with nature and foster the next generation of conservationists. Becoming a member of Families in Nature will give your family the opportunity to have adventures in nature, experience field science, develop as youth conservation leaders, and make memories that will last a lifetime. Memberships are free for everyone.

Who are we?

Families in Nature works to create opportunities for nature connection with the purpose of sparking a deep love and desire to protect, conserve and restore the environment. Our mission is to connect children and their families to nature and to each other through time spent learning, playing, and volunteering outdoors. It is our vision to inspire ALL families to fall in love with nature and foster the next generation of conservationists.

Pease Park Conservancy works in partnership with the City of Austin to set the standard for the principles of world-class park management – emphasizing environmental excellence – to improve the quality of this treasured green space for the enjoyment of all.

Our mission celebrates the diverse ecology and history that make Austin’s first public park valuable and unique. The Conservancy works to restore, enhance and maintain this 84-acre public green space for the sustainable use and enjoyment of all.