silurian system in a sentence

Examples

1. In 1832 Dr Thomas Lloyd, a Ludlow doctor and amateur geologist, met Roderick Murchison at Ludford Corner to study the rocks exposed along the River Teme and on Whitcliffe, advancing Murchison's theory for a Silurian System that he was to publish in 1839 . Immediately above the topmost layer of the marine rock sequence forming Murchison's Silurian period was a thin layer of dark sand containing numerous remains of early fish, especially their scales, along with plant debris, spores and microscopic mites.