Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/418



The chief difference to be observed in the strata of the two Pentowan Stream Works, is the want of marine matter in those of the upper. In the lower Stream Work I have described the killas rock, upon which are deposited 5 feet of tin ground, 10$$\scriptstyle \frac 12$$ feet of vegetable matter, 24 feet of sea mud, and 3 feet of soil, on a level with which flows the river 54$$\scriptstyle \frac 12$$ feet above the solid rock.

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The following notice and sections have also been transmitted to the Society.

British antiquities (celts, spear's heads, &c.) have been discovered in the Stream Works at the depth of 20, 30, and 40 feet, from whence it appears probable that the greatest part of the accumulation of soil has taken place at a comparatively modern period.

An accurate representation and description of the Stream Work at Porth in the parish of St. Blazey, of this county, have been presented to the public by Philip Rashleigh, Esq. in the second part of his Description of British Minerals, published in the year 1802.