WIL KiN?LE AND ] GULF BROOK SECTION. 95 
Ft. in. 
18. Dark -gray sandy shale and flags 14 
17. Bluish-gray sandy shale 1 3 
16. Hard bluish-gray sandstone 1 6 
15. Dark bluish-gray shale 3 
14. Dark bluish-gray sandy shale, partly covered 12 
13. Bluish-gray hard sandy limestone 9 
12. Olive-gray sandy shale 6 
11. Covered (to forks of brook) 60 
10. Soft olive-green shale nearly barren of fossils 20 
9. Soft olive-green shale 3 
8. Hard olive-green sandstone 6 
7. Soft olive-green shale, interstratified with harder sandy beds 10 
6. Soft olive-green sandy shale 5 
5. Covered and sandstone 3 6 
4. Hard flaggy dark-brown sandstone 6 
3. Covered 4 
2. Hard sandy olive shale 6 
1. Soft olive-gray clay shale 1 6 
The most important stratigraphical feature of the Gulf Brook section 
is the belt of limestone bands associated with purple shales and sand- 
stones in the upper part of the section, comprising zones 58 to 75. 
This limestone belt is a constant feature over most of the western half 
of Bradford County, where it affords a most important key to the 
stratigraphy of the region. Sherwood applied the name Burlington 
limestone to its outcrops on the north side of the Towanda anticline 
near Burlington/' Since this name is preoccupied for a division of the 
Carboniferous of the Mississippi Valley, it is proposed to substitute 
the name Franklindale, because the beds are best exposed in the Gulf 
Brook section west of Franklindale. 
j Although the section shows no conglomorate horizon, a ti-foot bed 
lof coarse conglomerate caps a hill about a mile west of the section. 
talis conglomerate lies perhaps 300 feet below the Franklindale beds, 
(which outcrop near it. 
A band of conglomerate 8 or 10 inches thick outcrops one-third of 
a mile east of Gulf Brook, which lies a very little higher than the 
highest zone of that section. 
In the road, li miles west of Leroy, is an outcrop of a bed of iron 
ore which was supposed by Sherwood to be identical with a bed 
jexposed near the top of the Gulf Brook section. 6 Claypole c has 
[Clearly shown that it lies, as Lilley first pointed out, at a considerably 
shigher horizon, which he estimated at " perhaps 250 feet.'' The 
writer's measurements show a thickness of 284 feet of strata in the 
Gulf Brook section above the highest bed that approaches an ore 
in composition. The ore in question must therefore lie at Leroy some- 
a Second Pennsylvania Geol. Survey, Rept. G 37. 
blbid., p. 36. 
cProc. Am. Philos. Soc, vol. 20, 1883, p. 530. 
