Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/185

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but it is said that chalk makes its appearance at Temple Patrick, near the north-east angle of the lake, being there exposed by the excavation of the deep valley through which the Six mile water flows.


Flœtz trap.

This formation in Ulster comprises the following members.[1]

1. Tabular basalt,
2. Columnar basalt,
3. Greenstone,
4. Greystone,
5. Clinkstone porphyry,
6. Bole or red ochre,
7. Wacke,
8. Amygdaloidal wacke,
9. Wood coal.

The section given by Dr. Richardson of the cliffs near the Causeway well illustrates the arrangement of these substances in constituting the aggregate mass of flœtz trap.

  1.   Feet
    1. Basalt rudely columnar 60
    2. Red ochre or bole 9
    3. Basalt irregularly prismatic 60
    4. Columnar basalt 7
    5. Intermediate between bole and basalt 8
    6. Coarsely columnar basalt 10
    7. Columnar basalt, the upper range of pillars at Bengore had 54
    8. Irregularly prismatic basalt. In this bed the wacke and wood coal of Port Noffer are situated 54
    9. Columnar basalt, the stratum which forms the Causeway by its intersection with the plane of the sea 44
    10. Bole or red ochre 22
    11.
    12 Tabular basalt divided by thin seams of bole 80
    13.
    14.
    15. Tabular basalt occasionally containing zeolite 80
    16