Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/211

 the heaps of rubbish at the mouth of the pit are often so rich in ore that considerable sums are paid for the privilege of washing them.

Manganese is also found in this district: it has not however been worked to any extent. The principal pit from which it is taken is in the parish of Ashton on the slope of the hill overlooking the valley to the west of the church. It is found in an iron-stone vein crossing the limestone. What little is found is used at the glasshouses and potteries of Bristol, and at the bleach yards in the neighbourhood.

To the limestone succeed other beds, in which a red siliceous sand is the prevailing ingredient. They lie in very regular strata from a foot to two inches thick, and parallel to those of the limestone. They are best observed on the southern bank of the river along the towing path for the distance of about half a mile from where the limestone terminates. These beds extend on the south of the Avon to Leigh, Failand and Charlton, and on the north they pass near to Sneed park towards Westbury. Some of the beds of this formation near to Abbots Leigh make a fine stone for building.

Among the uppermost of these beds are several composed of sandstone, the fissures of which are coated by calc-sinter, then a thin stratum of sandstone with evident marks of vegetable remains; below which is a red slaty sandstone very micaceous, and then a bed of siliceous pudding stone about 12 feet thick containing in some parts a number of white quartz pebbles.

About the middle of this series of sandstones there is found a singular stratum about 3 feet thick, composed of irregular balls of limestone packed closely together, the intervals being filled with fine sand. Below this the red slaty micaceous sandstone is repeated and at length disappears, being the last of the highly inclined strata that can be distinguished.