Definition of Proterozoic
1. Noun. From 2,500 to 544 million years ago; bacteria and fungi; primitive multicellular organisms.
Group relationships: Precambrian, Precambrian Aeon, Precambrian Eon, Precambrian Period
Generic synonyms: Aeon, Eon
2. Adjective. Formed in the later of two divisions of the Precambrian era. "Proterozoic life forms"
Definition of Proterozoic
1. Adjective. (geology) Of, or relating to the geologic eon from about 2,500 to 570 million years ago; comprises the Paleoproterozoic, Mesoproterozoic and Neoproterozoic eras; marked by the build up of oxygen in the atmosphere and the emergence of primitive multicellular life. ¹
2. Proper noun. (geology) The Proterozoic eon. ¹
¹ Source: wiktionary.com
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Lexicographical Neighbors of Proterozoic
Literary usage of Proterozoic
Below you will find example usage of this term as found in modern and/or classical literature:
1. A Text-book of Geology: For Use in Universities, Colleges, Schools of by Louis Valentine Pirsson, Charles Schuchert (1915)
"The proterozoic era, or the time of first known life, represents a vast lapse of time ... For the distribution of the proterozoic formations see maps, Figs. ..."
2. Geology, Physical and Historical by Herdman Fitzgerald Cleland (1916)
"The Algonkian [proterozoic] is a series of rocks which is mainly sedimentary. ... When the Algonkian [proterozoic] rocks were laid down essentially the ..."
3. Geology by Thomas Chrowder Chamberlin, Rollin D. Salisbury (1905)
"By such comparisons and inferences, it is concluded that the general conditions of the proterozoic times were more like, than unlike, those of the present ..."
4. Geology by Thomas Chrowder Chamberlin, Rollin D. Salisbury (1905)
"Whether the stratigraphic records made in these intervals are ever identified or not, they must be taken into account in the conception of the proterozoic ..."
5. Geology by Thomas Chrowder Chamberlin, Rollin D. Salisbury (1907)
"But, taken as a whole, proterozoic times, as the descriptions of the formations will show, were marked by more igneous activity than the Paleozoic, ..."
6. An Introduction to Historical Geology: With Special Reference to North America by William John Miller (1916)
"Emphasis should be placed upon the fact that the proterozoic was the first era ... Judging by the records, the proterozoic, on one hand, was marked by less ..."
7. A College Text-book of Geology by Thomas Chrowder Chamberlin, Rollin D. Salisbury (1909)
"The proterozoic (Algonkian) formations appear at the surface between younger and older ... Geographic relations of the exposed proterozoic to the Archean. ..."
8. Research in China by Eliot Blackwelder, Bailey Willis, Rufus Harvey Sargent, Friedrich Hirth (1907)
"proterozoic STRATA. We recognize two principal systems of stratified rocks of the ... proterozoic rocks are best exposed in China, so far as yet known, ..."