| "Passage-beds." (Murchison.) |
Greenish-grey fine-grained grits with bands of slate resting on grey, brown, and purple slates and concretionary sandstones. | |
| "Croaghmarin beds." (Ludlow?) (About 1000 feet.) |
Grey, purple, and brown rough slates (cleavage and dip coincident). | |
| Purple and grey slates passing down into brownish and greyish cleaved slates and calcareous grits with fossils, Atrypa reticularis, Pentamerus Knightii, Rhynchonella furcata, Strophomena depressa, Orthoceras annulatum, &c.[1] | ||
| "Ferriter's Cove beds." (Dunquin Bay.) (Wenlock.) |
Fine-grained yellowish grits and sharp slates, with grey shales and brown fossiliferous sandstones, passing down into fine-grained purple grits and slates, weathering with cavities, with a base of purple brecciated beds[2]. | |
| Volcanic Series. |
Beds of purplish ash, lapilli, and agglomerate, sometimes finely laminated and traversed by cleavage-planes; with these are several beds of slate. | |
| "Smerwick beds." (Smerwick Harbour.) 2000 feet. |
Purplish, brown, green, and yellow sandstones and flags with bright red shales. No fossils, possibly of "Llandovery" age. |
The above section exhibits not only a gradual passage from the unfossiliferous "Dingle beds" into Upper Silurians, but an intercalation of these beds themselves throughout a thickness of 1500 or 2000 feet. The purple slates and grits shown in the section from Dunquin Inlet southwards, and lying well below the fossiliferous beds, are in no way different from the purple slates and grits which lie above the highest fossiliferous band. So much is this the case that, for some time, these beds were classed by Mr. Du Noyer with "the Dingle beds" until the discovery of the fossiliferous band above them, when the boundary was shifted further up. It is quite open, however, to any one to say that the one view is as correct as the other, and that the uppermost known fossiliferous band in the "Croaghmarin beds" is to be included in the "Dingle series."
Another section, showing the passage from "the Dingle beds" into the fossiliferous Silurians, is shown on the northern or western flanks of Mount Eagle, in a brook-course which descends towards Dunquin National School. The section is as follows (beds in descending order):—
| Dingle and Passage-beds. |
1. Purple rough slates, with bands of greenish grit. Several hundred feet in thickness. | |
| 2. Thin-bedded light-brown sandstones. 5 feet. | ||
| 3. Evenly-bedded bluish-green and purple flagstones and tiles. 20 feet. | ||
| 4. Yellowish fine-grained sandstones, micaceous, weathering yellow or brown. 25 feet.
Beds not seen (probably shales). | ||
| Upper Silurian beds. |
5. Beds not seen (probably shales). | |
| 6. Calcareous grits, weathering brown, with Upper Silurian fossils. |
In this section, as in the larger one along the coast, there is no
