By David Leather

Sand Composition

 

 

 

Bay of Grobust after storm winds have blown sand onto surrounding grassland, July 2006

 

 

 

 

 

 

 

 

 

 

 

Bay of Tafts, like Grobust, is almost entirely shell sand, including a few micro shells of foraminifera

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sand extraction and erosion has reduced the dunes behind Mae Sand

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The beaches of Westray and areas of wind-blown sand deposits

 

 

Sands of Westray

Sandy Beaches
There are seventeen wonderful almost white sandy beaches on Westray, plus a few minor ones. Grobust sands, being near to Pierowall is a favourite and is especially attractive when large green waves roll in one after the other from the north. Mae Sand is wild and beautiful and faces south. Bay of Tafts and Links of Garth form clean curves of white sand, while the white sands of Bay of Skaill make a fine place to contemplate the beauty of the island with Papay on the horizon. Sand o’ Gill, the Ouse and Bay of Tuquoy are quieter bays with huge areas of sands uncovered at low tide. Local people know well the properties of beach sands, whether good to sweeten the soil, or to make decent concrete or mortar, and where to obtain it.

The composition of the beach sand varies greatly between shell and quartz sands. There is no simple explanation why one sort of sand should be restricted to one beach and not another, though the quieter bays have quartz sand, and the beaches facing the open sea tend to be shelly. However the Bay of Tuquoy and Mae Sand both face the same direction and are only a mile or so apart yet the sands are very different.

The quartz sand is a medium to fine sharp sand, individual sand grains showing slightly rounded corners. This reflects erosion of Westray flagstone that originated from river sand, then in recent times has been worn to some extent by the sea. Really sharp sand will squeak when you scuff it with your foot. The graph will tell you which beaches have whistling sands. The sand derived from shell material is slightly coarser but mixes readily with the quartz sand. The dunes and most of the sand that has been blown inland is of the shelly type.

Sand dunes and wind-blown sand
Several Westray beaches are backed by sand dunes and some have wind-blown sand extending far inland. Behind Mae Sand there are thick beds of sand, now largely covered with vegetation, that extend as far as Netherwood House, South Hamar and Tuquoy. Immediately behind the beach, the high dunes have been exploited for sand extraction and are now deeply eroded. Much of the area is now a nature conservation site and lyme grass – a species similar to marram grass – is helping to keep the sands in check. In the Grobust Bay area wind-blown sand extends as far as Pierowall and northwards across the Links to Quoigrew. These are the two most extensive deposits, though many of the other beaches are backed by dunes or beds of sand, especially behind the Bay of Tafts where sand reaches beyond the main road where the Old School is. Around the Bay of Skail there is a 200m belt and most of Westray’s airport is on this sand bed.