W X Y Z

Glossary of geological terms

ABCDEFGHI J KL
MN OP QRSTU VW X Y Z

W

Welsh Borderland Fault System / System Ffawtio’r Gororau

Set of faults trending NE-SW through Shropshire and into mid and South Wales. It comprises the Church Stretton Fault Zone which extends south-westwards through the Geopark as the Carreg Cennen Fault, the Tywi Lineament and the Pontesford Lineament. It may be a terrane boundary.

Wenlock Series or Wenlockian / Cyfres Gweunllwg

Stage of the Lower Silurian. See Silurian timechart.

Westphalian / Westffalaidd

Stage (subdivision) of the Carboniferous Period. See Carboniferous timechart.

Windermere Stadial / Rhyng-gyfnod Cynhesol Windermere

Subdivision of the late Pleistocene Epoch between about 15,000 and 13,000 years ago during which Wales enjoyed a temperate climate.

Wrekin Terrane / Tiriogaeth grammenol Dinlle Gwrygon

A terrane is a section of the Earth’s crust, the rocks of which share a common geological history. Terranes are bounded by major strike-slip faults. The Wrekin Terrane is a roughly triangular area whose corners are at Tenby, Stoke-on-Trent and Bristol.  It is defined by the ‘Malvern Lineament‘ in the east, the ‘Variscan Front‘ in the south and the ‘Welsh Borderland Fault System’ (see above) in the north-west. Most of Fforest Fawr Geopark lies within these boundaries.

Wye Glacier / Rhewlif Gwy

A broad glacier or river of ice which flowed down the valley of the present-day River Wye during one or more of the ice ages.

X

no terms

Y

no terms

Z

Z limestone / calchfaen Z

See Vaughan’s biozones