LOWER LIAS: LINCOLN. 175 
Details were recorded by Mr. W. H. Holloway, who calculated the 
thickness of the several zones : these may be summarized as 
follows : 
FEET. 
A. capricornus to A. oxynotus : Chiefly clays with septaria and 
occasional sandy beds - - - 470 
A. semicostatus to A. planorbis : Alternations of limestone and 
clay 230 
Lincoln. , 
Near Lincoln the Lo.ver Lias occupies a broad belt of flat 
country that affords few sections : the minor features in the area 
being in many cases due to coverings of Drift. 
The basement-beds belonging to the zone of Ammonites planorbis, 
are represented by dark clays with bands of grey earthy and shelly 
limestone, but as a rule there appears no great mass of limestones 
either in this division or higher up in the Lower Lias. 
East of Collingham railway- station there was a quarry and 
lime-kiln, now abandoned, and the section showed in 1889, about 
4 feet of clay, and loose blocks of grey earthy and banded lime- 
limestone, like the Insect-beds of Warwickshire. At this locality 
Mr. W. H. Dalton collected Ammonites planorbis, Avicula inatqui- 
valvis, A. papi/ria, Lima yiyantea, Ostrca liassica, &:c. 
The boring at South Scarle (Collingham) proved about 29 feet 
of Lower Lias clay and limestone.* The limestones were exposed 
in the railway -cutting south-east of Torksey, and the beds have 
been extensively quarried there for local building-purposes. f 
Beds of clay and shale with bands of limestone, represent the 
zones of Ammonites anyulatus and A. BiicMandi. They have been 
noticed near Eagle, in cuttings south of Marton railway-station, 
and near Stow, in the brickyard south of Heapham, and near 
Great Corringham. Ammonites Bucklandi> Grypheea arcuata, 
Lima gigantea, Pcntacrinus^ &c. occur. 
More interest attaches to a band of ferruginous and calcareous 
sandstone, with subordinate clays,' that represents the zone of 
Ammonites semico status. It has been traced, by Messrs. L T ssher and 
Dalton, at intervals northwards from the area previously noted in 
the Vale of Belvoir, but the outcrop can only be detected in 
places. North of Bassingham Church the following fossils were 
obtained;]; . 
Amberleya gaudryana. 
Chemnitzia (?) liassica. 
Gryphaea arcuata. 
Lima. 
Ostrea. 
Pinna. 
Pholadomya ambigua. 
Unicardium cardioides. 
Rhynchonella. 
Spiriferina Walcotti. 
Pecten Thiollieri. 
A somewhat similar assemblage was obtained north of Eagle, 
although the beds there appear to be on a rather lower 
horizon. 
* E. Wilson, Quart. Journ. Geol. Soc., vol. xxxv. p. 812. Sec also W. H. 
Dalton, Geol. Mag. 1887, p. 48 ; Geol. Lincoln, p. 194. 
f Geology of the country around Lincoln, p. 17. 
j Geology of Lincoln, pp. 19, 20. 
