1Relating to or denoting the earliest aeon of the earth's history, preceding the Cambrian period and the Phanerozoic aeon.Compare with Cryptozoic
- ‘The crest of the Blue Ridge is usually underlain with Precambrian or Cambrian igneous rocks.’
- ‘It extends upwards from a depth of about 6 km, at which depth Precambrian crystalline basement is predicted from seismic refraction studies.’
- ‘Turquoise here was found as vein fillings and nodules in weathered Precambrian granite.’
- ‘Plenty of suitable sedimentary deposits exist within the late Precambrian and Cambrian strata.’
- ‘By the early years of the twentieth century, as the geology of the continents began to be better known, it was realized that Permian and Precambrian glacial deposits occur virtually on all continents and at low latitudes.’
- 1.1as noun the Precambrian The Precambrian aeon or the system of rocks deposited during it.
We take a look at several popular, though confusing, punctuation marks.