ABOUT OXFORD QUARRY

Oxford Quarry is located in View Hill which is 16 km west of Oxford, which is on the way to Woodstock. The quarry is 185ha on Chalk Hill which derived its name from The Austin Chalk Company which originally extracted the lime to make wallboard chalk in 1960. The lime is now mainly used for Agricultural purposes.

As can be seen below there are a number of layers within the quarry and more recently the Basalt Rock has been used as Riprap for Seawall and River Protection as well as rock for Stonemason and landscape rock purposes.

There are actually three quarries on Chalk Hill, with differing rock colours, grey/blue, brown and black. The Bentonite Clay can be used for pond lining, well drilling, and cosmetic purposes. The Silica Sandstone can be used for artificial turf, making cast iron moulds, horse arenas and a number of other uses.

The rock identified as being highly suitable for armoured protection (riprap) and targeted by quarrying operations at Chalk Hill is a basaltic lava deposit of the Harper Hills Volcanic Group. The lava flow erupted onto the floor of a shallow lake, given that the underlying Bentonitic clay is of lacustrine (lake deposited) origin (Browne, 1983). The submarine nature of the lava flow is evident in that there is a scoriaceous, brecciated base to the lava flow caused by rapid quenching as the flow moved along the lake floor. As basalt flowed, the portion in contact with the lake water cooled first, forming a crusty rind. This is also evident in the abundant vesicles (gas bubbles) present in the basal breccia and the lower portion of the basalt caused by steam and preserved in the rock as it cooled. The resulting basalt rock has more vesicles the closer it was to the base of the flow. The basal flow breccia contains fragments of vesiculated, scoracious pieces of basalt that were broken up as the lava flowed and were reincorporated into the rock as it cooled. Cooling underwater also results in palagonite. Palagonite is a clay mineral that forms via the hydration and ion exchange between the quenched basalt and water.