lG4r The Lower Devoniax Deposits of Marylaxd 



Vertical Total 

 thickness vertical 

 feet thickness 



Massive dark blue limestone. Favosites pyriformis ? near 

 base 13.6 98.8 



Massive dark blue nodular limestone. Base of this unit 107 

 feet west of base of section 19.0 85.2 



Thin-bedded dark blue limestone. Camarotwchia litchfield- 

 ensis. 50.7; Favosites sp., 45.6, 48.4; Rhynchospira glohosa var. 

 abundant at base 21.2 66.2 



Thin-bedded dark blue limestone, weathering nodular; Rhyn- 

 chospira globosa var. abundant. Top of unit 62 feet west of 

 base of section 8.8 45.0 



Thin-bedded dark blue limestone weathering nodular. At base 

 occurs Chonetes jerscyensis. Top of unit 50 feet west of base 

 of section 6.6 36.2 



Thin-bedded nodular blue limestone carrying crinoid frag- 

 ments. At base occur Chonetes jerseyensis (a), Spirifer mo- 

 destiis. Uncinulus convexorus. Top of unit 41 feet west of base 

 of section 19.6 29.6 



Concealed, with occasional outcrops of thin-bedded nodular 

 limestone 10.0 10.0 



Thickness of Keyser member 272.6 



Total thickness of Helderberg formation 293.1 



ToNOLOwAY Formation 

 Concealed with occasional outcrops of thin-bedded, platy lime- 

 stone. 



The following species are found in the lower beds of this section, their 

 exact horizon not being known: Elcedenia harretti, Kloedenia kummeli, 

 KIcedenia nearpassi, Klcedenella pennsylvanica, Leperditia elongata, Leper- 

 ditia gigantea. 



The section at Round Top Station on the Western Maryland Railroad 

 east of Tonoloway extends from the top of the Clinton to the base of the 

 Helderberg. However, the Keyser member is exposed only in places on 

 the mountain side, which is steep and not easily accessible. The Lower 

 Keyser fossils found in the talus at this place are: Spirifer vanuxemi, 

 Atrypa reticularis, Reticularia hicostata, TeniacuUtes giiracantlius, and 

 Whitfieldella minuta. 



XVII. Section at Hancock 



There are two exposures of limestone on the southwestern edge of the 

 town, along the west flank of Cove Ridge, that are included in one section, 



