crosscutting into slices
1Precambrian time — Interval of geologic time from с 3. 8 billion years ago, the age of the oldest known rocks, to 544 million years ago, the beginning of the Cambrian Period. This interval represents more than 80% of the geologic record and thus provides important… …
2geology — /jee ol euh jee/, n., pl. geologies. 1. the science that deals with the dynamics and physical history of the earth, the rocks of which it is composed, and the physical, chemical, and biological changes that the earth has undergone or is… …
3Trans-Hudson orogeny — [ North American craton, also called Laurentia.] [ Wyoming, Superior and Hearne cratons] The Trans Hudson orogeny, Trans Hudsonian orogeny, Trans Hudson orogen (THO), or Trans Hudson Orogen Transect (THOT), (also referred to as the Trans… …
