These are sedimentary rock layers chronicling Earth's geological history. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by ...

Mudstone, shale, and limestone are examples of sedimentary rock likely to contain fossils. As the layers of sediment build up on top of one another, they create a physical timeline. The oldest layers, ...

The principle of superposition states that in an undeformed sequence of sedimentary rocks, each layer of rock is older than the one above it and younger than the one below it (Figures 1 and 2).

NASA’s Perseverance rover recently captured a stunning image of a black-and-white striped rock on Mars, sparking excitement ...

Southwestern Ohio's limestone (a sedimentary rock) is saturated with life — life from about 450 million years ago, that is. Our local limestone layers reflect times of relative prosperity for the wide ...

These layers of sedimentary rock were deposited in Cambrian time, when another shallow sea covered this region. Among the fossilized remains found within these layers are brachiopods, trilobites ...

Over time, the layers are compressed and glued together.Metamorphic rocks are formed from other rocks, igneous or sedimentary, which are heated and compressed underground.Igneous rocks are formed ...

The gigantic Yellowstone Grand Canyon, lined with volcanic rock. With all the effects of hydrothermal activity, river erosion ...

Groundwater dynamics in sedimentary rocks, particularly in Hokkaido ... flows through fractures at shallow depths, while deeper layers show a more stagnant condition. This suggests that the ...