236 Reports & Proceedings—Liverpool Geological Society. 
the east. Of much interest, too, was the discovery at Bock Bay of 
a volcano, which had been active during the great Ice Age, and the 
occurrence of numerous hot springs, which had built up beautiful 
oe of carbonate of lime. 
‘“‘ Exhibition of Specimens and Fossils from Lowe Sound and 
ie Island.” By HM: Cadell, B.Sc.) HAR Sah 7 IRD Anon 
Grange, Linlithgow. 
LIVERPOOL GEOLOGICAL SOCIETY. 
March 8, 1921.—W. T. Walker, Hsq., B.Sc., F.G.S., President, 
in the chair. 
The following paper was read: “Notes on the Geology of 
Lingdale.” By F. T. Maidwell, F.G.S. 
Lingdale was defined as the western slope of a wide, shallow 
valley-head, ranging from the high ground between the Uplands and 
the southern end of Bidston Hill in a north-easterly direction to 
the western side of Birkenhead Park. Many small exposures of 
what is presumably Lower Keuper Sandstone occur in the road- 
sides and lanes, as well as in the old quarries at Flaybrick Hill. 
The dip of the rocks is generally to the north-east, but the district 
is much cut up by faults ranging chiefly north and south, although 
there are some east and west faults which change the direction and 
amount of the dip, and bring in the Waterstones to the south of 
Howbeck Road. Detailed descriptions and measurements were 
given of the succession of strata in two instructive sections, where 
the junction of Yellow Upper Bunter Sandstone and the Keuper 
Basement beds is displayed. 
CornisH Institute or ENGINEERS. 
April 2, 1921. 
“Ore Deposits of Igneous Origin.” By R. H. Rastall, Sc.D., 
M.Inst.M.M., F.G.S. 
Ore deposits of igneous origin can be divided into two main: 
groups: those associated with acid intrusions usually take the 
form of veins or lodes. They belong to the latest phases of cooling 
and tend to concentrate in the upper parts of the intrusive masses ; 
furthermore, they commonly accompany pneumatolytic phenomena. 
The ore-bodies associated with the basic rocks, on the other hand, 
usually separate at an early stage, the intrusion often splitting into 
two immiscible liquid phases, as shown by Vogt in the case of the 
sulphides. The metalliferous phase, being the heavier, sinks to the 
bottom, although, owing to imperfect equilibrium and viscosity, 
this sinking is often incomplete and segregations of ore may be 
found at any level. An unusual type is afforded by the magmatic 
iron ores of Swedish Lapland, where concentration has been effected 
by sinking in an acid intrusion. The association of chromite and 
