Page:Quarterly Journal of the Geological Society of London, vol. 25.djvu/358

 II. Geology of Hastings.

1. Recent Deposits. — Before describing the several geological formations of the county, a few superficial deposits of local occurrence and of recent origin merit a brief notice, partly from their geological interest and partly from their economic value. Thick beds of a white shell-marl, charged with Cyclas, Planorbis, and other freshwater shells, are scattered here and there over the surface of the county. In many of the small shallow lakes this marl is still in course of deposition. The waters of such lakes often contain carbonate of lime to such an extent that any object exposed to their action is readily coated with a calcareous incrustation. From July to November many of these lakes are more or less completely dried up, and the marly deposits covering the bottoms are then exposed. " Lime Lake," a considerable expanse of shallow water in the southeast angle of Hungerford, derives its name from the calcareous deposit which it thus throws down. Marl-beds of a similar lacustrine origin often attain a thickness of several feet, and sustain a rank vegetation — cedar-swamps (arbor vitoe), for example, commonly standing upon such deposits. The occurrence of this freshwater marl is well exposed on the drift forming the higher banks on the west side of the river Moira above Belleville. No attention has hitherto been directed to the utilization of this shell-marl ; but it obviously possesses considerable value to the agriculturist as a fertilizer, and may perhaps be useful to the metallurgist as a flux, as well as for making the cupels or hearths used in refining auriferous and argentiferous lead.

In a country which possesses no workable quantity of coal, more than ordinary interest attaches to the occurrence of peat. Deposits of this fuel, often of considerable thickness, are extensively distributed through the mineral regions of Canada, and must eventually play an important part in the development of its mineral resources. Nearly all the smaller lakes scattered over the Laurentian area contain, either at their outlets or in sheltered coves along their margins, considerable accumulations of vegetable remains, which have partly grown in their present position and partly been drifted thither by winds or by the current of the river flowing through the lake. Year after year these stagnant accumulations are increased, and eventually become converted into a peaty substance sufficiently compact to admit of a rich vegetable growth upon the surface.

In connexion with the occurrence of peat, attention may be directed to the deposits of hog iron- ore, which are widely distributed over the surface of the country, and in certain localities appear to be still in course of formation. Although bog iron-ore usually contains phosphorus, it yields an iron which from its easy fusibility is highly valued for castings. Bog- ore has been employed with most satisfactory results at the St. Maurice and Radnor forges, both in Canada East. The bog-ore of Hastings is especially abundant in the township of Marmora, but has not hitherto been brought into use.