MIDDLE LIAS: STROUD. 215 
The Marlstone has been quarried in several places near Clinch- 
combe Fields, where it forms a broad platform. On the high- 
road leading towards Tails Hill, the large quarry on the south 
side, showed the following section : 
FT. IN. 
Upper /Pale grey clay, with nodules of pa)e mottled 
Lias. I bluish-grey earthy limestone - - 1 6 
fHard ferruginous sandy limestone, blue- 
Middle | hearted in places : with Belemniies, Am- 
Lias { monites, large Grypheea, Terebratula punc- 
(Marlstone). tata, Rhynchondlaacuta, and.R. tetrahedra 
[_ (in clusters) - - - 15 
Avicula, Cardinia crassissima, and Pecten cp.quivalcis are 
recorded by Moore. The beds are much shattered and broken up 
where not covered by Upper Lias. The stone is quarried for 
road-metal, and for building walls, &c 
At Newnham (or " Newent ") quarry south-west of Cam, the 
Marlstone is 20 feet thick, according to Moore. From this rock 
many Urchins, including Eodiadema, were found by Mr. Heeby 
Thompson and Mr. W. D. CriJc. They found that the " Tran- 
sition bed " (with Ammonites acutus] was represented, though not 
O clearly as in Northamptonshire.* 
In ihe escarpment south-cost of Frocester the Marlstone, 
according to Moore, is reduced to 2 feet in thickness, while the 
total thickness of the Middle Lias has been estimated at 150 feet. t 
Near Stroud the Marlstone Eock-bed is not so well developed 
as at Stinchcombe, for it is represented by a group of micaceous 
sandy clays, that contain inconstant beds of hard calcareous 
sandstone of variable thickness, and nodular and iron-shot marl- 
stone. These beds have been exposed at Dudbridge Mills, in an 
adjoining brickyard in the valley towards Nails worth, and also in 
the railway-cutting by Rooksmoor Mill, Woodchester, where about 
12 feet of ferruginous sandstone, overlaid by iron-shot rock with 
Belemnitcs, was exposed. 
The following section at Dudbridge Mills, is by E. Witchell: J 
FT. IN. 
River gravel - - - - 2 
f 10. Light brown calcareous sandstone, with 
Ammonites spinatus, Belemnites paxillo- 
sus, Avicula incequivalvis, Grypheea cym- 
bium, Pecten cequivalvis, and Unicardium 
cardioides - - -30 
9. Light brown or grey shaly clay - - 8 
8. Dark brown ferruginous rock (marlstone), 
Middle 
with A. tnargaritatus, B. paxillosus, 
^ U. cardioides, &c. - - 1 
I 7. Brown marly shale - - 8 
| 6. Light brown soft sandstone, blue in the 
I centre, with nodules and shelly layers, 
Pentacrinus, &c. - - -30 
5. Blue and brown ferruginous sandy clay -36 
4. Dark blue clay - - - -04 
[_ 3. Ferruginous nodules - - 6 
f 2. Light blue sandy clay, partly consoli- 
j dated - - 3 
I 1. Dark brown or bluish shaly clay 30 
* Thompson, llp. Brit. Assoc. for 1891, p. 350. 
| Wright, Quart. Journ. Geol. Soc., vol. xii. p. 303. 
I Geol. l^troud, p. 17. 
