|Coalisland Brick Pit||Tyrone|
|General view of western part of the excavations at Coalisland Brick Pit, Co.Tyrone.|
|Site Type: ||Pit|
|Site Status: ||PASSI|
|District: ||Dungannon District Council|
|Grid Reference: ||H8366|
|Rock Age: ||Carboniferous (Westphalian)|
|Rock Name: ||Coal Measures, Subcrenatum Marine Band|
|Rock Type: ||Coal, Mudstone, Sand, Sandstone|
|Fossil Groups: ||Brachiopod, Goniatite|
|Other interest: ||No data, Fluvial sediments, Lacustrine sediments, alluvial plain|
Summary of site:
This small area of Carboniferous Coal Measures is one of only two in Co. Tyrone, and so is of considerable importance.
The exact age of these rocks is not known but they are thought to be at or near the base of the Westphalian stage which begins the Coal Measures (equivalent to the major British coalfields). Only a newly excavated section in the north-east corner of the brick pit has been measured. The dominant rock type is grey unfossiliferous mudstone, weakly bedded, with thin beds of fine grained grey sandstone. These sediments total 10m in thickness and are topped by a thin coal seam (25cm thick) which could be the Seat Coal known from underground workings.
Around 310 million years ago this area was part of an extensive coastal deltaic plain, fed by fresh water streams clouded with grey mud or, in flood conditions, carrying slightly coarser sand. The plain at this point never dried out sufficiently to allow soils to become established and the plant debris was washed into the area, accumulating as peat layers that were ultimately converted into coal.
This rare outcrop needs considerably more research to determine the age and general environmental conditions at the start of the great coal forming era in the Carboniferous period in this part of Northern Ireland.