476 TRANSACTIONS OF SECTION C. 
6. Preliminary Nole on the Classification of the Permian of the North- 
East of England. By Davin Wootacort, D.Sc., F.G.S. 
Sedgwick, Howse, and King classified the Permian according to the 
nature of its stratification or of the structures occurring in it; but as the 
bedding of the different divisions is often alike, and as the structures— 
whether concretionary, brecciated, pseudo-brecciated, or cellular—are not 
confined to particular horizons, divisions named on this basis are mis- 
leading and unsatisfactory. The use of the term ‘ fossiliferous’ to mark 
off a division is also inadmissible. In the following classification the 
limestone is typically developed at the place the name cf which is used to 
designate a group of strata. The divisions in descending order are :— 
Middlesbrough Red Beds with Salt.—Red marls, marly sandstones and 
lenticular beds of salt, anhydrite and gypsum with fcetid fossiliferous mag- 
nesian limestones. 300 feet. 
Roker Limestone.—Yellow limestone, regularly bedded ; some beds com- 
pact, others formed of minute hollow spheres. 100 feet. 
Fulwell Rocks.—Bedded yellowish and brownish concretionary (of 
various types) and non-concretionary limestones, in places highly fractured 
and brecciated ; cemented crush-breccia occurs locally. Base often much 
disturbed by beds from below being forced into it, and by falling of lower 
layers into fissures and gashes. Irregular beds of amorphous marl are 
associated with these beds. Two fossiliferous horizons occur; one of fish 
remains at Fulwell, and the other of invertebrata at Byers Quarry. 150 to 
200 feet. 
Marsden Rocks.—Bedded yellow and brown limestones, slightly concre- 
tionary in places. Irregular masses of white limestone resembling Mountain 
Limestone occur. Brecciated beds (cemented crush-breccias) occur at 
different horizons: in places highly folded and fractured, but sometimes 
little disturbed. Breccia-fissures and breccia-gashes are found principally 
in this division. It is sometimes ‘ cellular,’ due to solution of fragments 
out of cementing material of brecciated beds. This horizon has been a zone 
of thrusting, the amount of brecciation being determined by the relative 
compressive strength and rigidity of the strata. A flexible limestone occurs 
near the top of this division. 150 to 200 feet. 
Claxheugh Limestone.—Yellow, earthy, friable, and crystalline lime- 
stone. Generally unbedded, in places very fossiliferous, sometimes brec- 
ciated (crush-breccia) and highly fractured. Its upper surface is very 
irregular. Some of the brecciated beds between Frenchman’s Bay and 
Marsden, on Tynemouth Cliff, and at Blackhall Rocks are included in this 
division. Outcrops roughly parallel to coast as a continuous band. 
Brachiopods and most of the other genera of Permian fossils stop at this 
horizon in Durham. 50 feet. 
Houghton Limestone.—Regularly bedded, thinly at base, more coarsely 
above. Top layers often highly displaced and tilted up; in one or two 
places it is entirely thrust out of position. Thickens greatly from north 
to south of county, and width of outcrop increases. Often full of geodes, 
10 to 400 feet. ; 
(The greatest thickness of magnesian limestone obtained by boring is 
about 800 feet.) 
Marl Slate.—Greyish, yellowish-brownish, and blackish arenaceous and 
argillaceous laminated limestone. Numerous fish remains. Three or four 
feet thick. 
Thin band of calcareous clay a few inches thick. 
Yellow Sands.—An incoherent sandstone generally yellow along outcrop, 
occasionally variegated (iron oxides and manganese dioxide). In pit 
sections often greyish or bluish. Very variable in thickness. Top originally 
regular, but floor on which it rests irregular. Generally false-bedded, 
