——_  _ ——— 
*Vol. 58.] PERMIAN, AND TRIASSIC OF THE ISLE OF MAN. 659 
| Nose {iNew 2? No. 3. No.4) Now ase NosG: 
Luyurn Batua- Knock- | Baua- 
| Moar. | WHANE. | E-DOONEY. | GHENNEY, 
Bie ie J Re) Gee ee ine eaten tes een ree 
Glacial Drift ....c....6c068. 167 6 (|171 O 173 QO. 212 .4. (298 O /364:0 
Saliferous marls ......... He anaes 1 II ate ee Gp  ccrCER Senta ate! IN Pate 382 0+/557 4 
(Dip 12°.) 
Mriassic sandstone.........|  ...e oiion mee 4382 3 (748 9 
EDipsc-vo., 10.to 12°.) | 
iormarane SOLOS! << te acesqus| wcecdesu| aseees Olen 84 9 
Yoredale Series............ It, cichis 136 3 | 283 0 (240 2+ 
(Dips 30°, 35°, 388°.) | 
CarboniferousLimestone 65 6+ 37 Ji+ 15 
(Dip 40°.) 
iw) 
It is obvious, from the succession of these rocks and their increase 
in thickness along a north-easterly line, that they all dip in natural 
order to the north, or away from the Ordovician massif of the 
island. 
It is also clear, from the above table, that they constitute a plateau 
of marine erosion (fig. 2, p. 657) sloping northward and eastward, 
and extending from a depth of about 150 feet below Ordnance-datum 
on the west at Lhen Moar, to a depth of about 348 feet at the Point 
of Ayre. Were the Glacial Drift resting upon it removed, the sea 
would occupy the whole of the area north of a line drawn between 
Ramsey and Kirk Michael. To realize the great thickness ofthe Drift, 
it is necessary to add the height of the hills of Drift above the level 
of the boreholes, which gives a total of not less than about 450 feet, 
a greater thickness than has been proved elsewhere in the British 
Isles. 
The Carboniferous and post-Carboniferous rocks in the Isle of 
Man stand in the same relation to the pre-Carboniferous massif as 
those of the Lake District. The same rocks occur in the same order, 
dipping away in every direction from the massif, both north and 
south. Here, as there, they probably form concentric rings, now 
broken, round the Silurian (and Ordovician) massif, being repre- 
sented in the south by the Basement Carboniferous and Carboni- 
ferous Limestone of Langness and Castletown; in the north by the 
Carboniferous Limestone, the Permian, and the Triassic sandstones 
and marls, which have been described in this and the preceding paper. 
Tt must further be noted that during the time of the accumulation of 
the Permian Series in the north of the Isle of Man, the Ordovician 
grits and phyllites, now forming by far the greater part of the cliffs, 
were not exposed to the erosion of the sea on the Permian coast-line. 
The cliffs then in the north of the island were mainly composed of - 
Carboniferous Limestone and Yoredale rocks. This fact is proved 
not merely by these rocks having been the source from which the 
Permian strata were derived, but also by their occurrence in the sea- 
worn plateau underneath the Permian of the north of the island. 
222 
| Point or AYRE. 
