PROCEEDINGS
OF
THE GEOLOGICAL SOCIETY.
POSTPONED PAPERS.
1. On the Graphite of the Laurentian of Canada.
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By J. W. Dawson, LL.D., F.R.S., F.G.S.
(Read June 23, 1869[1].)
In my paper of 1864, on the Organic Remains of the Laurentian Limestones of Canada, as a sequel to the description of Eozoon Canadense, I noticed, among other indications of organic matters in these limestones, the presence of films and fibres of graphitic matter, and insisted on the probability that at least some of the lower forms of plant life must have existed in the seas in which gigantic Foraminifera could flourish. Dr. Hunt had previously, on chemical evidence, inferred the existence of Laurentian vegetation[2], and Dana had argued as to the probability of this on various grounds[3]; and my object in referring to these indications in 1864, as well as to the supposed burrows of annelids, subsequently described by me[4], was to show that the occurrence of Eozoon was not to be regarded as altogether isolated and unsupported by probabilities of the existence of organic remains in the Laurentian deducible from other considerations.
Now that the questions which have been raised regarding Eozoon
- ↑ For the Discussion on this paper see p. 406 of the last volume of the Journal.
- ↑ 'American Journal of Science' (2), xxxi. p. 395. From this article, written in 1861, after the announcement of the existence of laminated forms supposed to be organic in the Laurentian, by Sir W. E. Logan, but before their structure and affinities had been ascertained, I quote the following sentences: — "We see in the Laurentian series beds and veins of metallic sulphurets, precisely as in more recent formations; and the extensive beds of iron-ore, hundreds of feet thick, which abound in that ancient system, correspond not only to great volumes of strata deprived of that metal, but, as we may suppose, to organic matters which, but for the then great diffusion of iron-oxyd in conditions favourable for their oxydation, might have formed deposits of mineral carbon far more extensive than those beds of plumbago which we actually meet in the Laurentian strata. All these conditions lead us then to conclude the existence of an abundant vegetation during the Laurentian period."
- ↑ Manual of Geology. I may also be permitted to refer to my own work 'Archaia,' p. 168, and Appendix D, 1860.
- ↑ Quart. Journ. Geol. Soc. vol. xxii. p. 608.
