PART 2 .] 
Theobald: Axial group in Western Prome. 
37 
Brought forward ... 2,728 9 
Dark harsh shales and dark thin bedded grey sandstones, none over 
4 inches in thickness ... 
154 0 
Massive argillaceous sandstone 
6 0 
Dark harsh shale and sandstones (as above) 
319 0 
Do. but thicker bedded 
25 0 
Do. but thinner bedded (as above) 
129 0 
Shales and sandstones 
344 0 
- 976 O 
/. 
Pale massive sandstones gritty and in places finely conglomeratic 
103 0 
Pale sandstones gritty, grey and creamy and thin bedded ... 
12 0 
Do. very massive 
6 0 
Hard grey sandstone 
26 0 
-147 0 
Total 
... 3,851 9 
At or near this point the junction of the nummulitics seems to 
come in, but this is not 
very clear, and it may he in reality a few hundred feet higher. 
A measured thickness of 
nummulitics now offers of 
1,810 feet. 
followed by an estimated section of ... 
... 2,307 „ 
or fully 4,000 feet of nummulitics ... 
4,117 feet. 
The following epitomises this section : — 
Ascending. 
Ft. In. 
Lower * axials’ (shales, &c.) seen, more than 
300 0 
a .— Cardita (?) shales ... 
110 0 
b. —Limestone shales, &c. 
33 3 
Upper ‘ axials.’ c—Freckled grits, &c.... 
... 1,364 6 
d.— Shales and sandstones 
... 1,221 0 
e .— Do. do. 
976 o 
f .—Sandstones and conglomerates 
147 0 
3,851 9 
The Nummulitic section I shall give elsewhere, but as the upper beds of the group 
are not represented in it, the entire thickness of this group cannot be safelj' placed at less 
than 6,500 feet, and as the lower axials are, I think, thicker than the upper, 8,500 will 
hardly he an overestimate for that group, giving a total thickness of about 15,000 feet of 
beds throughout which fossils are so rare as to be practically of no use in sub-dividing so 
unmanageable a mass of strata or correlating even neighbouring sections. In spite of 
these drawbacks, however, the above section is valuable from the great thickness of beds 
exhibited without any reversal^ of dip, and by its seeming to embrace the greater part 
* My colleague, Mr. Fedden, in noticing this section, speaks of “ something very like a fault/’ but his account is 
too meagre to be of much use in fixing the spot, and his section only embraces 800 feet of beds in all. He also speaks 
ol the beds “ rolling and dipping in various directions,” which, I consider, conveys an inaccurate idea, if 
thereby auy reversal of dip is implied, and again where he continues “doubtless these are a repetition of the 
former beds.” It is true that the great thickness of beds here seen dipping with very general regularity, a little 
troubled in places, but nowhere reversed, would suggest the idea of faulted repetition of the same beds, but there 
is nothing in the beds themselves to countenance this. L do not think there are auy faults cutting through the hods 
of the section given by me, and they alone could aft'eet the question. Reversal of dip there is none also, and there 
only remains the question of obliquely folded beds. For this the group seems to me too thick. It is possible to 
conceive such a cause for the excessive thickness here displayed by some of the groups of shales, hut then they appear 
to be in perfect sequence with beds which certainly have not been thus folded, such as the characteristic white 
speckled grits. It will be noticed that I have grouped the section into divisions; now, each division taken by itself 
presents a certain uuiforunty of facies and type, which in some instances might possibly result from the excessive 
plication of a comparatively small group of beds, but where these large groups of varied character follow one another, 
such a supposition is no longer tenable, and the only result is the conclusion that the entire section is a bond Jide 
display of thickness,—a conclusion borne out by our knowledge and observation of the entire group elsewhere. 
