pebbles, and ironstone-nodules cemented pretty firmly together, and passing up into fine yellow sand, laminated and well bedded, and this again covered by the gravelly loam which lies indifferently upon chalk or sand. The chalk is fissured, rises in little craggy prominences into the drift (b), or shows steep short escarpments against which the chalk-rubble has accumulated. I saw it in this form at Hertingfordbury a few weeks back.

However, we have only to return to the station, and enter the bay in the cliff where the lime-kilns are at work, to see the accompanying section. South of the gravel-shoot, the chalk descends rapidly, dipping N. or N.W. to within 10 feet of the road-level, and is much shattered in the hollow. The fine gravelly sand, underlain by 2 or 3 feet of conglomerate, follows it; and then, just under the shoot (which seems put there to protect the section), it is suddenly faulted to the extent of at least 7 feet, and probably more, showing the clean face of a fault which has cut through chalk, chalk- and flint-pebbles, and gravelly drift, the faces of the faults, three or four in number, and parallel to each other, being as clearly defined in the hard drift and conglomerate bed (the pebbles of which are often fractured across) as in the chalk itself. The loam and chalk-rubble mixed descend irregularly into the hollow, and leave generally but a foot or two of undenuded gravel-drift above the conglomerate.

Section of Chalk, Drift, and Upper Gravels at Hitchin Station.

The section here is so very clear as to admit of no doubt; and I leave the matter for the consideration of those who are apt to forget that faults in the drift imply a very recent modification of the surface by movements similar in kind, if in less degree, to those which produced our mountain-ranges.

5. On some FLINT IMPLEMENTS lately found in the VALLEY of the LITTLE OUSE RIVER, near THETFORD. By J. W. FLOWER, Esq., F.G.S.

(The publication of this paper is unavoidably deferred.)

[Abstract.]

THE sands and flint-gravel on the right bank of the river Ouse at Thetford form a terrace 8 to 10 yards above the river, and about 40 yards distant from it. At a spot called Red Hill a large number of flint implements have lately been obtained from this gravel, at from 12 to 15 feet below the surface, and within a foot or less of the chalk on which the gravel rests; and some were found in the same gravel filling pot-holes in the chalk.

The author pointed out the exact correspondence, as regards geological position and relations, between the Thetford gravels and the flint-implement-bearing beds of Amiens, Abbeville, Fisherton, Icklingham, Hoxne, &c. He further noticed the close resemblance which these implements and some others discovered in England bear to those of the valley of the Somme; and concluded by expressing his dissent from Mr. Prestwich's conclusions, and stating his own views on their mode of accumulation, remarking that, in his opinion, these implements were manufactured prior to the severance of this island from the continent.

6. GEOLOGICAL NOTES of the PACIFIC COAST of ECUADOR, and on some EVIDENCES of the ANTIQUITY of MAN in that REGION. By J. S. WILSON, Esq.

(Communicated by Sir R. I. Murchison, Bart., K.C.B., F.R.S., F.G.S.)

[Abstract.]

THE western slope of the Cordilleras is occupied with projected volcanic matter, presenting an irregular aggregation of boulders, gravel, sand, fine earthy matter, or ashes, and pumice. The boulders are of various sizes, and consist principally of the more ancient and the hardest plutonic rocks. Small angular fragments of granite are occasionally met with many miles from where that rock is found at the surface, and where there exists no evidence of their having been transported by water.

In some of the older strata of this volcanic rock, extending along the coast and some distance inland, occur cavities, that have been once occupied by the roots of trees, in their original place alongside prostrate stems, which indicate that there were periods of repose of the volcanic agencies by which the materials constituting this rock were distributed. Traces of forest-vegetation in the volcanic material were found on the coast and in some of the older beds of that deposit, commonly below high-water mark, and also at various points up the river Esmeraldas, and at all altitudes up to the foot

VOL. XXII.-PART 1.

2 Q

of Pichincha. In this latter locality, and in beds of more recent date than those which extend to the coast, roots and stems of small trees, completely carbonized, have been found, some descending to the depth of 100 feet below the surface. Whilst the trees in this latter locality, though of more recent production, are converted into perfect charcoal, those of the older volcanic deposits are not at all carbonized. And, again, the wood of the buried forest at the mouth of the Esmeraldas, lying only 12 to 15 feet under beds of an estuarine clay, and much more recent than either of the above, is partially carbonized, and resembles lignite. It is the author's opinion, in regard to the charred wood in the vicinity of Pichincha, that, as the ashes and dust thrown out by that volcano fell in dense showers over the surrounding country, the heat still retained by this matter carbonized the trees which it enveloped and buried.

It is beneath this volcanic deposit, or in some of its lowest beds, that the gold-drifts are found, as at Playa de Oro, Cachibi, at Barbacous, New Granada, &c. And it is only when this deposit has been removed, or where ancient river-courses have been again penetrated by waters of more recent times, that gold is found in this part of Ecuador and the adjoining part of New Granada.

The projected volcanic matter is distributed in terraces, the most recent of which extends along the shores of the Esmeraldas, and is but slightly above high-water mark. The second rises in some places 10 feet above the former, and is extensive at the lower part of the Esmeraldas and up the valleys of its lower tributaries. A third, presenting a distinct margin, rises about 8 feet higher; and above this rise three other terraces, respectively, in their orders of ascent, 15, 12, and 6 feet. This is the arrangement which (with the exception of the lowest and therefore the most recent terrace) is clearly defined in ascending the north side of the river Esmeraldas from opposite the river Viche to the Quebrada of Chancama (see section). At the former place the terraces recede from the river to an undetermined distance, but which is evidently extensive, and are said to reach to the Rio Verde, which receives a portion of the drainage from them: this seems the more probable, as but an inconsiderable amount of the water falls into the Esmeraldas. The series of terraces is again met with in the road above the mouth of the river Sadi, their continuation being partially broken by the projection of a range of hills. It is observable in this locality that the river has cut its way deep across the terraces, and in many places completely through the volcanic matter, and regained its more ancient bed on the Carboniferous rocks.

Rocks of Tertiary age are represented in the limestone cliffs, resting on shale, north of the Rio Verde, and at the side of the river Esmeraldas, just above the old town of that name, where the limestone is overlain with the volcanic deposits. Again, the Tertiary limestone was found much further up, where the river passes through a range of hills in the vicinity of the river Caninde; here it appears by the river-side in enormous white angular blocks, which had evidently fallen from the side of the precipitous hill behind: the

limestone appeared to rest on the volcanic deposits, and it was the washing away of this latter from underneath that caused the harder limestone to break off in those enormous blocks. So far as the author's observations yet extend, the earlier beds of the volcanic material are at least contemporaneous with the Tertiary limestone; and the accumulation of these volcanic outcastings continued until long after the close of the Tertiary period, but became gradually more circumscribed.

The second of the terraces described contains, in many places, remains of articles of human art (broken pottery, earthen figures, and fragments of gold ornaments) at various depths below the surface, but in all cases below high-tide mark, from which fact it is apparent that this region, during its occupation by man, stood higher above the sea than it does now. But the sea gradually encroached on the land, till it attained a height of about fifteen feet above its former level. That the duration of time occupied by this advance and retreat of the sea must have been very great is apparent when we consider that the stratified earth of the plain is simply the sediment brought down by the rivers and deposited beneath the margins of the sea, in some places to the depth of ten feet above the surface on which the ancient cities stood. Again the land sank and deposited those low flats and islands found at different places along the sea-margins. The land is again gradually sinking.

The pottery-stratum is traceable along a line of 80 miles of coast, and, by partial observations, is determined to occur under corresponding conditions for a distance of 200 miles more.

The discovery of pottery in a formation considered by the author immensely older than the clay-beds of the coast, in the uppermost, excepting one, of the terraces described, was made at Chancama,

situated 24 miles from the coast, 180 feet above the sea, and 50 feet above the Esmeraldas river. The section (see fig.) exhibits undisturbed sea-distributed gravel and sands, 6 feet 6 inches in thickness, the lower part of which contains fragments of pottery.

7. On the RELATIONS of the TERTIARY FORMATIONS of the WEST INdies, By R. J. LECHMERE GUPPY, Esq., F.G.S. With a Note on a New SPECIES of RANINA, by HENRY WOODWARD, Esq., F.G.S.; and on the ORBITOIDES and NUMMULINE, by Prof. T. RUPERT JONES, F.G.S. (Abridged.) [PLATE XXVI.] CONTENTS.

Ir may be that some apology is needed for again bringing before the Geological Society the subject of West-Indian Geology. I should not, indeed, have ventured to do so, but for the circumstance that the considerations involved do not alone concern the geology of the West Indies, but have an important bearing on several questions connected with the distribution of organic beings in Europe and Asia, and on the correlation of deposits in those countries. These questions have much interest for geologists; and I believe that the facts and arguments presented in this communication are such that my labour in bringing them together will not be lost, even if the hypothetical views I have built upon them should prove to be untenable. Moreover the present communication forms a necessary sequel to those I have already had the honour of laying before the Society.

My object now is to present some general remarks on the results obtained by recent investigations into the geology and palæontology of the West-Indian islands. But before going into these, it may be as well that I should review our knowledge of the deposits, beginning with the oldest Tertiary formations.

§ 2. EOCENE FORMATIONS.

The existence of Eocene strata in Jamaica has been demonstrated by Mr. Barrett* and by Dr. Duncan and Mr. Wall+. Determinable

* Quart Journ. Geol. Soc. vol. xvi. p. 324. + Ibid. vol. xxi. p. 1.