No. 104.] 183 



In 1864, Prof. James Hall and Sir William Logan yisifced the dis- 

 trict and announced, as a result of their examinations, the existence of 

 Laurentian rocks in the Highlands.* 



In the same year Prof, (ieorge H. Cook, State Geologist of New- 

 Jersey, mapped the Highlands (west of the Hudson and the New 

 Jersey range) as Azoic.\ 



The same district was represented, with much detail of geological 

 boundaries, on the map of northern New Jersey, which accomi^anied 

 the *•' Geology of New Jersey," published in 1868. The term Azoic 

 was retained. J 



Keference has already been made to several articles by Prof. Jas. D. 

 Dana on the geological structure of the south-eastern part of the 

 State. § The term Archman was proposed by him in 1872 for the 

 gneisses of the Highlands, in an article in the American Journal of 

 Science, on the " Poughquag Quartzite."|| In 1879, and in the same 

 journal he gave the boundaries, in part, of the Highlands Archa?an 

 on a small (page) geological map of that part of the State. 1" In sub- 

 sequent articles on the "Geological relations of the Limestone Belts 

 of Westchester county," Prof. Dana assigns the crystalline rocks of the 

 Highlands to the Archaean ; and in one of them he gives a map show- 

 ing these belts with the Archaean of Putnam county. ** Eeferences to 

 the rocks of Dover or East mountain, which have been described in 

 the preceding pages of Archa3an and an outlier of the Highlands, are 

 made by the same author in a paper entitled " on Taconic Kocks and 

 Stratigraphy," published in March, 188o.tt 



The crystalline rocks of the Highlands of New York have been de- 

 scribed in this report as belonging to the Archcean ErcL This term 

 has been accepted in preference to the older designation. Azoic, be- 

 cause it is not open to the objections which are forcibly opposed to the 

 use of the latter, when applied to these rocks. We cannot draw the 

 line where life began on the globe, but from the standpoint of a grad- 

 ual development from lower to higher organisms it is reasonable to as- 

 sume that the earliest life consisted of infusorial protophytes, which 

 lived in conditions such as prevailed during the deposition of the first 

 sediments. And they may have given rise to much of the carbon- 

 aceous and siliceous deposits so common in these crystalline gneisses, 

 limestones and associated strata. A priori we should not look for the 

 preservation of the earliest microscopic forms in beds which have been 

 so metamorphosed as the older crystalline rocks. The presence of 

 limestone, graphite and apatite with beds of iron ore prove as much 

 for the existence of life as the reverse. Again the term Azoic is 

 expressive of a negative condition and not in harmony with the other 

 terms of the geological scale. It is not as consistent with Palceozoic, 

 Mesozoic and Cejiozoic as Archcsan, which refers to a period of geologi- 



* Am. Jour, of Science (2), XXXIX, pp. 96-97. (Notice of a paper read Defore the Nat. 

 Hist. Soc. of Montreal.) 



^ Am. Report of t/ie State Greolof/ist, for ISQi, map facing page 23. 



I Geology of New Jersey, 1868, Portfolio of maps ; Maj} of J^ortJiern, New Jersey. 



iSee pages of this report. 



J Am. Jour, of Science (3), III, pp. 253-254. 



t Am. Jour, of Science (3), XVII, p. 879 



**Am. Jour, of Science (3), XIX, p. 191; XX, pp. 21-22; and 368-375; XXII, pp. 105-103, 



^^Am. Jour, of Science (3), XXIX, pp. 209, 221. 



