Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/417

 {| style="font-size:85%;line-height:140%;" surface
 * || || || align="center" | Depth from
 * || || || align="center" | Depth from
 * || || align="right" | Feet || align="right" | Feet
 * align="right" valign="top" | Stratum 4. || Sea mud, with large oyster shells and cockles || align="right" valign="bottom" | 4 || align="right" valign="bottom" | 39
 * align="right" valign="top" | 5. || Vegetable substances, with flat compressed leaves, and a few rotten shells || align="right" valign="bottom" | 6$$\scriptstyle \frac 12$$ || align="right" valign="bottom" | 45$$\scriptstyle \frac 12$$
 * align="right" valign="top" | 6. || Vegetable substances, without shells; containing rushes, fallen trees, flat compressed leaves, roots covered with moss and compressed to an oval form, wings of coleopterous insects || align="right" valign="bottom" | 1 || align="right" valign="bottom" | 46$$\scriptstyle \frac 12$$
 * || The trees in 2, 5, and 6, are so numerous, that the miners collect from them great stacks of fire-wood.
 * align="right" valign="top" | 7. || At the top are found moss, sticks, hazle nuts. Beneath are small stones of killas, growan, and other pebbles, which are known by the miners to have belonged to the neighbouring halls, so far distant as Hensbarrow || align="right" valign="bottom" | 3 || align="right" valign="bottom" | 49$$\scriptstyle \frac 12$$
 * align="right" valign="top" | 8. || Rough tin ground, containing the lighter and poorer stones || align="right" valign="bottom" | 2 || align="right" valign="bottom" | 51$$\scriptstyle \frac 12$$
 * align="right" valign="top" | 9. || Rough tin ground, containing rich tin stones, some of great size and weight. Mixed with these are rounded pebbles of quartz, and other stones, and a yellow ferruginous clay || align="right" valign="bottom" | 3 || align="right" valign="bottom" | 54$$\scriptstyle \frac 12$$
 * align="right" valign="top" | 10. || Solid killas rock, on which all the preceding alluvia were deposited. The level of this does not differ much from that of low water mark.
 * }
 * align="right" valign="top" | 7. || At the top are found moss, sticks, hazle nuts. Beneath are small stones of killas, growan, and other pebbles, which are known by the miners to have belonged to the neighbouring halls, so far distant as Hensbarrow || align="right" valign="bottom" | 3 || align="right" valign="bottom" | 49$$\scriptstyle \frac 12$$
 * align="right" valign="top" | 8. || Rough tin ground, containing the lighter and poorer stones || align="right" valign="bottom" | 2 || align="right" valign="bottom" | 51$$\scriptstyle \frac 12$$
 * align="right" valign="top" | 9. || Rough tin ground, containing rich tin stones, some of great size and weight. Mixed with these are rounded pebbles of quartz, and other stones, and a yellow ferruginous clay || align="right" valign="bottom" | 3 || align="right" valign="bottom" | 54$$\scriptstyle \frac 12$$
 * align="right" valign="top" | 10. || Solid killas rock, on which all the preceding alluvia were deposited. The level of this does not differ much from that of low water mark.
 * }
 * align="right" valign="top" | 9. || Rough tin ground, containing rich tin stones, some of great size and weight. Mixed with these are rounded pebbles of quartz, and other stones, and a yellow ferruginous clay || align="right" valign="bottom" | 3 || align="right" valign="bottom" | 54$$\scriptstyle \frac 12$$
 * align="right" valign="top" | 10. || Solid killas rock, on which all the preceding alluvia were deposited. The level of this does not differ much from that of low water mark.
 * }
 * }

In addition to these observations I have not many remarks to offer. The lower work is much richer in metallic produce than the upper, owing probably to the valley being narrower at the former place, which confined the mineral matter within a smaller space, and prevented it from being dispersed in the plain. The stones at the upper work were much the largest, as might be expected from its greater proximity to the hills. Among the tin stones of both works are found such as agree with the ores of particular lodes, that traverse the several hills all the way up to Hensbarrow hill, and the old miners had themselves made these distinctions, and rendered them perfectly clear to me. Thus, I think, I may venture to say, that the tin stones have been washed down from the neighbouring hills into the Pentowan valley.