NO. 3 UPPER CAMBRIAN TRILOBITE FAUNAS — RASETTI 15 



Thickness 

 Feet 

 Collection cnr/20 in thin lenses in top 1 foot : 



Aphelaspis camiro c 



Aphelaspis laxa r 



Aphelaspis quadrata c 



Collection cnq'/20 in thin bed 2j^ feet below top : 



*Aphelaspis washburnensis 



Aphelaspis, sp. undet. 



Aphelaspidella macropyge 



Glaphyraspis declivis 



Collection cnq/20 in thin beds and lenses, 10-14 feet above base : 



Aphelaspis walcotti cc 



Glaphyraspis oderi c 



Collection cnp720, in thin beds and lenses 6-8 feet above base : 



Aphelaspis minor c 



Glaphyraspis oderi r 



Collection cnp/20 in lenses and nodules 1-4 feet above base : 



Aphelaspis lata cc 



Cheiloccphalus brevilobus r 



5. Limestone : in rather thick beds, with some shale intervals 7 



4. Shale and thin-bedded limestone 5 



Collection cnn/20, 1 foot above base : 



Crepicephalus, sp. undet. 



Terraiiovella dorsalis 



3. Limestone : in rather thick beds, with some shale intervals 6 



2. Shale, siltstone, and thin-bedded limestone. Unit extends almost to 



northern end of railroad cut 27 



Collection cnm720, 35^ feet below top : 



*Amiaspis obsolescens 



Coosia alethes 



Collection cnm/20, 1 1 feet below top : 



Kingstonia inflata 



The Washburn section supplies one of the most complete successions 

 of Aphelaspis faunules observed in Tennessee, and is probably un- 

 equaled in the number of fossils of the Aphelaspis zone. The trilobites 

 are mostly well preserved, including the extremely numerous larval 

 stages of Aphelaspis present in collection cnw/20 (pi. 20, fig. 1). 



JEFFERSON COUNTY 



The Nolichucky formation is partly exposed near the crest of 

 Shields Ridge, in the New Market and Jefferson City quadrangles. 

 Three localities yielded important fossils and information about the 

 faunal succession. 



New Market-Piedmont Road. — The Nolichucky formation is in- 

 completely exposed along the road on the N. and S. slopes of Shields 

 Ridge. The top of the lower limestone unit crops out where the road 

 crosses the summit. This locality yielded numerous trilobites to early 



