Basalt with xenolith – North Berwick
 >View Microscope
 >View Object
Fact sheet
Description: 

This plagioclase-phyric basalt with xenoliths was collected near  the Harbour, in the town of North Berwick, although the lava flow from which it comes, the Dunsapie basalt, is named after a crag and small loch on Arthurs Seat in Edinburgh. The sample is Carboniferous in age, and was one of a suite of volcanic eruptions in the Scottish borders at this time.

In thin section the plagioclase phenocrysts appear altered, particularly along cracks. Large almost circular amygdales (vesicles filled with secondary minerals) appear to be filled with very fine grained material, possibly zeolites which form a lining of fibres radiating inwards and an inner zone of random orientations with some rosettes of radiating crystals. Other amygdales contain radiating bundles of coarser grained zeolite crystals. A large xenolith of a banded rock occupies about a quarter of the thin section. The xenolith may have been derived from the local sediments and tuffs but the minerals of the xenolith are altered so it is difficult to be certain of its origin.

In Place
In Time
infoImage: 
Location description: 
Close to the Scottish Seabird Centre, The Harbour, North Berwick
Accuracy:
Location precision: 
Good
Timescale:
Timescale: 
Carboniferous
Ma = Millions of years ago
In Focus
Theme:

Theme:

What\
Type:
Type: 
igneous
What\
Category:

Category:

What\
Accessory minerals:

Accessory minerals:

What\