Layers of Sedimentary Rock

Teach students to read rock layers like pages in a book with this one-page worksheet! Students learn the law of superposition, then number a set of rock layers from oldest to youngest.

The passage explains that the stripes of rock in a cliff or canyon wall are layers of sedimentary rock. Each one formed when sand, mud, or shells settled at the bottom of a lake or sea, one layer on top of another. The bottom layer settled first, so it is the oldest, and the top layer settled last, so it is the youngest. This rule is called the law of superposition. Students also learn which rocks sand, mud, shells, and pebbles become. A Key Words note defines sediment, superposition, and fossil, and a simple doodle shows a layered cliff. In the first activity, students study a diagram of four labeled rock layers, sandstone, limestone with fossils, shale, and conglomerate, and number them from 1, the oldest, to 4, the youngest. In the second activity, students circle the rock that forms from sand and from mud, then use their layer diagram to decide if the fossils are older or younger than the sandstone. The sheet is written to Texas TEKS 6.10C and also fits NGSS MS-ESS2-1.

What's inside:

• A short passage with a doodle and a Key Words note
• A rock layer diagram with 4 layers to number
• 3 circle the answer questions
• A visual answer key

How teachers use it:

• After the Rock Cycle worksheet, as an intro to reading rock layers
• For bell work, stations, or an exit ticket
• As homework or sub plans, with no prep needed

It takes about 10 minutes and prints clearly in black and white. This worksheet is part of our Reading in Science series on Earth's systems.