GREAT OOLITE SERIES : SLEAFOKD. 427 
masses of jet and bands of pyritous sandstone, in which occur 
remains of Fishes, Ostracoda, and Paludina. 
Mr. Dalton also notes that the Upper Estuarine Series was 
admirably exposed, to nearly its full thickness, in the laihvay- 
cutting at Heighington. The beds lie in a slight synclinal, and to 
the eastward abut against a faulted face of the Inferior Oolite. 
Their natural junction with that rock is marked by a feature 
crossing the line at the Station, and below the level of the rails. 
The cutting shows the following sequence* : 
FT. IN. 
Limestone - - - - -110 
Great Oolite 
Limestone. 
Shales with three hard sandy bands, 6 to 
12 inches thick, full of Ostrea - -77 
Estuarine <{ Ochry shale 
Series. Grey shale 
Tea-green shales - 3 5 
, Ochry shale - 3 6 
Upper Green shale - 4 6 
2 6 
- .63 
I White sand, about 14 feet, but seen to 
I depth of - - - - -80 
The hard sandy or calcareous gritty bands, which I have 
grouped with the Great Oolite Limestone, contain Ostrea 
Sowerbyi, 0. subrugulosa, and Rhynchonella. At Metheringham 
the Great Oolite Limestone comprises beds of shelly ragstone, 
with clay-bands yielding Ostrea, 
Near Greetwell the following appears to be the sequence 
of the several beds, as observed by Mr. Dalton in the railway - 
cutting : 
FT. IN. 
LimestoB ' l Limesfcone passing down into greyish- 
blue clay, Rhynchonella, Ottrea, &c. - 14 
oEC . J 
("Hard sand of a pale mauve tint - -16 
jy Blue clay weathering yellow and brown- 6 
r, , J Hard sand, pale mauve, with carbona- 
Jistuarn "\ ceous plant-markings - .90 
Line of nodular limonite with veins of 
fibrous gypsum. 
Lincolnshire Limestone. 
In the Sudbrook Holme well-section, the following beds, 
referable to the Upper Estuarine Series, were proved : 
FT. IN. 
Green Clay - - - - - - 3 8 
Stone - - - - ..54. 
Clay - - - - - - 15 
The full thickness of the Great Oolite Limestone in this 
neighbourhood; is about 20 feet ; the beds comprise ragstones 
and marls, and they yield remains of Fishes, Mollusca, Echino- 
derms and Corals. 
Further north, as remarked by Mr. Ussher, the Upper 
Estuarine Series appears to be largely composed of sand, irregu- 
* Usshei, Geol. Lincoln, pp. 62-65. 
