sedimentary

Comparing the findings of the 1964 earthquake core samples to samples deeper in the coastal stratigraphy, the research team discovered sedimentary and diatom evidence of three other instances where the splay fault ruptured.

Collisions between tectonic plates buried these sedimentary rocks deep in the Earth's crust where radiogenic heat released by the shale triggered melting of the lower crust.

One thing about the PVP that delights Coffey is that it is composed of all three kinds of rock — sedimentary, metamorphic and igneous.

The study focuses on 15 middle-Devonian sedimentary rock samples from the Appalachian basin in the U.S.

The researchers identified fossilised plants and plant debris, fossilised tree logs, traces of roots and sedimentary structures, preserved within the sandstone.