Vol. 58. | GLACIER-LAKES IN THE CLEVELAND HILLS. 491 
sandstone (perhaps Triassic); grains of red marl (perhaps Triassic) ; 
Liassic rocks and fossils representing every division ; Jurassic sandstones . 
and limestones; Chalk and flints (generally black, and not of the 
indigenous Yorkshire type). 
2, Meramorrputc Rocks. 
Gneisses and schists. 
3. Ianzous Rocks. 
Granites from the South-west of Scotland (Criffel, etc.) ; holocrystal- 
line rocks (including Shap Granite), lavas, and ashes from the northern 
and eastern portions of the Lake District and the Vale of Eden; the 
Whin Sill, and Cleveland Dyke; porphyrites from the Cheviot Hills; 
elxolite-syenite, laurvigite, and rhomb-porphyry from the Christiania 
Fjord. Quartz-porphyries, granites, etc., the place of origin of which is 
at present doubtful. 
The rocks may be grouped, according to the probable or ascertained 
place of origin, in the following manner :— 
I. South-western Scotland. 
Criffel Granite. 
II. The Lake District and the Vale of Eden. 
Shap Granite, lavas and ashes of the Borrowdale Series, 
Brockram, Carboniferous conglomerate, vein-quartz. 
III. Teesdale or other valleys of the northern part of the Pennine 
Range. 
Carboniferous limestones, grits, sandstones, and cherts. 
IV. South-eastern Scotland (Valley of the Tweed) and Cheviot Hills. 
‘Greywacke’ sandstones and conglomerates, jasper, 
porphyrites. 
V. Eastern Durham. 
Magnesian Limestone (botryoidal type of Roker, near 
Sunderland). 
VI. Christiania region. 
Rhomb - porphyries, laurvigite, elzolite-syenite, and 
perhaps some of the ‘greywacke’ sandstones and 
conglomerates (‘sparagmite’), many metamorphic 
rocks. 
VII. Gulf of Bothnia. 
Post-Archean granite of Angermanland, and probably 
some quartz-porphyries. 
VIII. Denmark, or bed of the North Sea. 
Black fiints. 
These series may be arranged again in three sets, to indicate the 
possible routes by which they travelled. Series I, I, & Il] may 
well have travelled together in a movement from the Irish Sea by 
way of the Solway Firth, the Vale of Eden, Stainmoor Pass, and the 
Tees, probably with a loop-line via the Tyne. This may be termed. 
the Western Group. 
Series IV and V have probably travelled in company, as the coast 
of Durham lies immediately in the path from the Cheviots to the 
Cleveland area. It is possible that some of the Carboniferous rocks 
and the Whin Sill may have come by this route from Northumber- 
land; but, except the Cheviot porphyrites, no distinctive Northum-. 
brian rock such as the ‘ Pea-Post’ (Saccammina-limestone) has yet 
been found in Yorkshire. It should, however, be pointed out that 
the Pea-Post is generally an extremely friable rock, unlikely to. 
