Azoic

The oldest sedimentary rocks are devoid of fossil remains and so they are called the Azoic or Archæan.

The Doctrine of Evolution Its Basis and Its Scope Henry Edward Crampton

The Laurentian rocks were at first spoken of as representing "Azoic" time; but in 1846 Dawson found a formation deep in their midst which was believed to b e the fossil relic of a very low form of life, and after that it became customary to speak of the system as "Eozoic."

A History of Science: in Five Volumes. Volume III: Modern development of the physical sciences 1904

Azoic period is not altogether orthodox -- i.e., that the origin of these beds is largely due to the ejection of mud, sand, and ashes from subterraneous sources, which, settling in shallow seas, were afterwards altered to their present form.

Getting Gold: a practical treatise for prospectors, miners and students

America, of Azoic, Silurian, Devonian, and Carboniferous formations, shored up against each other by the gradual upheaval of the continent, although unquestionably older palæozoic and secondary beds underlie, here and there, the later formations.

The Atlantic Monthly, Volume 18, No. 105, July 1866 Various

In the European ocean of the Azoic epoch we find five islands of considerable size.

The Atlantic Monthly, Volume 12, No. 69, July, 1863 Various

Silurian rocks of Bohemia were divided into certain stages (A to H) -- the two lowermost, A and B without fossils (Azoic), succeeded by the third stage, C, which included the primordial zone, since recognized as part of the Cambrian of Sedgwick.

Encyclopaedia Britannica, 11th Edition, Volume 3, Part 1, Slice 3 "Banks" to "Bassoon" Various

Chloride of gold is at present day contained in sea water and in some mineral waters, and would have been likely to be more abundant during the Azoic and early Paleozoic period.

Getting Gold: a practical treatise for prospectors, miners and students

They follow each other from east to west in a narrower area, just as the Azoic, Silurian, and Devonian deposits follow each other from north to south in the northern part of the United States.

The Atlantic Monthly, Volume 12, No. 70, August, 1863 Various

Now, most of these Canadian rivers are Azoic in character; hence their grim and formidable beauty.

Crowded Out! and Other Sketches 1897

No, I would chose the St. Maurice or the Richelieu, the Lièvre or the Saguenay, the Ottawa or portions of the St. Lawrence, with the grim Azoic rocks, the turbulent rapids and the somber pines.

Crowded Out! and Other Sketches 1897