84 Brown — Silurian Limestone of Milesburg Gap. 



This section was described by Rogers in 1858 and lie gave a 

 cross section to illustrate the structure of the region (fig. 1A). 

 This is his description :* 



" The next exposure of the Scalent (cement) and Pre-meridian 

 limestones is at the Old Eagle Furnace, 200 yards up the unusu- 

 ally long and gentle ascent of the mountain. On the west side of 

 the gap, the limestone strata are seen dipping 45° W. 70° N. 



" They appear again in vertical layers on the summit of the 

 short hill opposite the foot of the mountain, and again, dipping 

 30° N. 30° W., in the face of the next little ridge at the north 

 ^oot of which flows the creek. Thus we have a synclinal aand an 



Fig. 1. 



VfiTQ'N 



A B J±L 



/I. Sc 



SfftfreM. Ud. 



go zooY* 



BE. tit (dap) 



Sea /.eve/ 



Fig. 1-A. Copied from Rogers' "Fig. Ill, — Section at Eagle Furnace, 

 Bald Eagle Creek Valley." in the Final Report of the First Geological Sur- 

 vey of Pennsylvania, p. 546. This section is along the line A-B, fig. 3. 



Fig. 1-B. A section along the line C-D, Fig. 3, Scale : 3" = 1 mile. 1, 

 Bald Eagle conglomerate ; 2, Juniata red shale ; 3, Tuscarora sandstone ; 4, 

 ? Clinton ; 5, Decker Ferry ; 6, Roudout ; 7, Oriskany (limestone phase) ; 8, 

 Oriskany sandstone. 



anticlinal flexure, in the former of which, 100 yards north of the 

 foot of the mountain, is a little patch of the Cadent black slate, 

 the sole relic of that formation. The Meridian sandstone lies in 

 fragments, with great deposits of sand, on the south slope of the 

 first, and forms the crest of the second little ridge. 



"The Pre-meridian or upper division of the limestone is filled 

 with curved and delicately formed corals, visible only on 

 weathered surfaces." 



In 1884, d'lnvilliers in "The Geology of Centre County " 

 quotes Rogers' description of these limestones and correlates 

 Rogers' Pre-meridian with the Lower Helderberg or Lewistown 

 limestone, No. VI of the Second Geological Survey of Penn- 



*H. D. Rogers, Final Report, Geol. Sur. of Pa., vol. i, p. 516. 



