60 C. II. Gordon — Mississippian Formations 



underlies the ore deposits. The upper portion in places 

 consists of flint breccia. The flint fragments, sometimes 

 carrying silver, are gray, brown, chocolate, pearl and 

 green, the green yielding a higher grade of ore than the 

 other colors. At the base is a bed 5 feet thick of coarsely 



crystallized yellowish-white limestone . 25 / 



5. Compact grayish limestone filled with nodular chert. 



Shale partings usually rather thick 50' 



JPercha Shale. (Devonian.) 



4. Grayish yellow and blue shales 60' 



3. Black fissile shale _ _ 100' 



Mimbres Limestone. (Siluro-Ordovicjan.) 



2. Pink limestone upper beds siliceous with drusy cavities; 



contains Silurian fossils 12' 



1. Quartzite and limestone below. 



By Clark, beds 7 and 8 were called " crinoidal limestones," 

 ]S T o. 6 "bine limestones," and No. 5 "nodular limestones." 



The recognition of the Lower Carboniferous (Mississippian) 

 facies of the fossils obtained from beds 7 and 8 is confirmed by 

 Dr. Girty. In the collection from the blue shaly beds (No. 7), 

 Dr. Girty identified the following species: — 



Fossils from Lake Valley. 



Zaphrentis, sp. Spirifer imbrex ? 



Favosites, sp. Spirifer aff. grimesi. 



Platyceras pileif or me Spirifer aff. peculiaris 



Jfegistocrinus evansii ? Delthyris nov a-mexicana 



Physetocrinus planus Syringothyris, sp. 



Trematopora vesiculosa Peticularia temeraria 



Fenestella, sp. Athyris lemellosa 



Pinnatopora, sp. Athyris aff. incrassata 



Crania, sp. Cleiothyris roissyi 



Leptaena rhomboidalis Petzia, sp. 



Phipidometta ? sp. Camarotoechia occidentalis 



Productus semireticulatus Phynchopora aff. pustidosa. 



ProdvcUis burlingtonensis ? Platyceras, sp. 



Productus aff. scabriculus Orthoceras, sp. 



Productus aff. arcuatus Goniatites ? sp. 



Producttts, sp. a Phillipsia peroccidens ? 

 Productus, sp. b 



The followino- were obtained from the overlving beds 

 (No. 8): 



Zaphrentis, sp. Trematopora americana 



Crinoid stems Phombopora, sp. 



Megistocrinus evansii ? Leptaena rhomboidalis 



Platyceras, sp. Schizophoria swallowi ? 



