Abstract
RECENT investigations have certainly tended to confirm the view originally advocated by my colleague, Dr. Carpenter, and myself, that a large portion of the bottom of the present sea has been under water and continuously accumulating sediment, at all events since the commencement of the “Cretaceous period,” and possibly much earlier. The marked parallelism which, setting aside all local dislocations and denudations, evidently exists between the Jurassic, the Cretaceous, the Tertiary formations, and the present sea-board, and the evident relation of that parallelism to the older rock axes, would seem indeed to indicate that the main features of the present physical geography may date from a period even anterior to the deposition of the older Mesozoic rocks. With many minor and temporary oscillations, of which we have ample geological evidence, the borders of the Oolitic, the Cretaceous, and the Tertiary seas, have apparently been successively and permanently raised, and the ocean over an area, the long axis of which may probably correspond with that of the Atlantic, proportionally contracted. The question simply is, whether, since the elevation of the Jurassic beds, any oscillation has at any time raised into dry land the whole of the trough of the Atlantic, so as to arrest the deposit of sediment abruptly over the area, and to extinguish all animal life, thus defining what seems to be popularly understood as the close of a geological period, and requiring the complete repeopling of the succeeding sea by immigration, or, according to another view, by the creation of an entirely new fauna. It seemed to us on the whole more probable that the successive elevations of the borders of the Mesozoic sea were accompanied by compensating depression and deepening of the centre of the trough, which may thus have been inhabited throughout by a continuous succession of animal forms; at all events, the onus of proof appeared to rest with those who maintained any breach of continuity.
Article PDF
Rights and permissions
About this article
Cite this article
THOMSON, W. On Deep-Sea Climates. Nature 2, 257–261 (1870). https://doi.org/10.1038/002257b0
Issue Date:
DOI: https://doi.org/10.1038/002257b0