Where: Tennessee (36.0° N, 83.5° W: paleocoordinates 30.0° S, 69.7° W)
• coordinate estimated from map
• outcrop-level geographic resolution
When: Blackford Formation, Llanvirnian (468.1 - 460.9 Ma)
• Whiterockian; All from Unit B; most from upper 8 feet of this unit
• formation-level stratigraphic resolution
Environment/lithology: peritidal; lithified dolomite and lithified, volcaniclastic conglomerate
•Layers and lenses of conglomerate and breccia are recurrent throughout this unit. These beds and lenses, usually 1/8 to 2 inches in thickness, contain angular to subrounded pebbles up to 2 1/2 inches in diameter. Most of the graded beds have a basal zone of angular pyroclastic granules. The breccia fragments are predominantly of volcanic origin whereas the subrounded pebbles are of a wide variety of lithologic types, some unknown in this vicinity.
•In many places the laminations of this unit have been contorted by the soft rock deformational processes of sediment flowage and slumping. Laurence (1944, fig. 6A and 6B) figured contorted laminations between undisturbed beds and an angular unconformity within a sequence of conglomeratic beds.
Size class: macrofossils
Preservation: mold/impression
Reposited in the USNM
Primary reference: K.E. Caster and H.K. Brooks. 1956. New fossils from the Canadian-Chazyan (Ordovician) hiatus in Tennessee. Bulletins of American Paleontology 36(157):157-199 [S. Holland/S. Holland/S. Holland]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 37450: authorized by Steven Holland, entered by Steven Holland on 15.03.2004
Creative Commons license: CC BY (attribution)
Taxonomic list
Cestites | |
Euchelicerata | |
Chasmataspis laurencii Caster and Brooks 1956 | |