Where: Lane County, Oregon (44.0° N, 123.0° W: paleocoordinates 44.4° N, 110.8° W)
• coordinate based on nearby landmark
• outcrop-level geographic resolution
When: Eugene Formation, Priabonian (38.0 - 33.9 Ma)
• Eugene Formation can be subdivided faunally: a lower unit correlating to the Keasey Fm, a middle unit correlating to the Gries Ranch Beds of WA, and a upper unit correlated with the Pittsburg Bluff Fm. Thickness of formation may be up to 15,000 feet, but probably around 5,000 feet. Most of the outcrops are scattered so it is difficult to estimate their relative stratigraphic placement
• bed-level stratigraphic resolution
Environment/lithology: transition zone or lower shoreface; lithified, tuffaceous, brown, gray, blue sandstone and tuffaceous, brown, gray, blue siltstone
•Hickman (1969): Several lines of evidence suggest that most of the Eugene Formation was deposited in shallow water, at depths no greater than 30 fathoms. The coarse, tuffaceous, and arkosic character of many beds and the interfingering of the Eugene Formation with non-marine tuffaceous rocks to the east and south indicates the proximity of the Oligocene shoreline. Although mollusks are generally not good indicators of depth, genera such as Panopea, Modiolus, Solen, and Spisula are presently restricted to depths of less than 40 fathoms. The high diversity of the benthonic fauna is an indication that the environment was not one of a bay or otherwise highly restricted environment. The absence of planktonic forms is typical of turbid, near-short environments. In the same units with these relatively undisturbed infauna! assemblages there are occasional thin layers of concentrated shell material which show definite signs of reworking and current sorting. The layers range from 1 to 10 cm in thickness and cannot be traced over great distances. The shells in these layers are small and include an admixture of infaunal and epifaunal species. The shells show little sign of wear or breakage, but many of the pelecypod valves are disarticulated, indicating some degree of transport. The scaphopods in these layers show parallel alignment by the current. There is also evidence that currents were intermittent and fluctuating in strength: the assemblages contain varying percentages of large shells mixed in with the smaller ones, and in some places there are higher proportions of broken and abraded shell debris mixed in.
Size class: macrofossils
Preservation: mold/impression, trace
Reposited in the CAS
Collection methods: quarrying,
• Collections held at University of Oregon, University of California, Californian Academy of Sciences (CAS), United States Geological Survey (USGS), and Stanford University (NP).
Primary reference: H. G. Schenck. 1931. Cephalopods of the genus Aturia from western North America. University of California Publications, Bulletin of the Department of Geological Sciences 19:435-490 [M. Clapham/K. Okamoto/M. Clapham]more details
Purpose of describing collection: taxonomic analysis
PaleoDB collection 39002: authorized by Austin Hendy, entered by Austin Hendy on 18.05.2004
Creative Commons license: CC BY (attribution)
Taxonomic list
Bivalvia | |
"Nuculana washingtonensis" = Nuculana (Saccella) washingtonensis
"Nuculana washingtonensis" = Nuculana (Saccella) washingtonensis Weaver 1916 pointed nut clam | |
Anadara (Anadara) sp. Gray 1847 ark | |
Crenella ? sp. Brown 1827 clam | |
Solena (Eosolen) eugenensis Clark 1925 clam | |
"Thracia condoni" = Thracia (Cetothrax) condoni
"Thracia condoni" = Thracia (Cetothrax) condoni Dall 1909 clam | |
"Spisula eugenensis" = Mactromeris eugenensis
"Spisula eugenensis" = Mactromeris eugenensis Clark 1925 clam | |
Macrocallista sp. n. sp. Meek 1876 venus clam
Pitar (Pitar) sp. n. sp. Römer 1857 venus clam
Pitar (Pitar) dalli Weaver 1916 venus clam | |
Parvicardium eugenense Clark 1925 cockle | |
Tellina aduncanasa tellin clam
Tellina (Moerella) lincolnensis Weaver 1916 tellin clam
Tellina pittsburgensis Clark 1925 tellin clam | |
Martesia sp. Sowerby 1824 clam | |
Mya (? Arenomya) kusiroensis Nagao and Inoue 1941 softshell clam | |
Lucinoma acutilineata Conrad 1849 clam | |
Scaphopoda | |
Dentalium (? Fissidentalium) laneensis Hickman 1969 tusk shell | |
Gastropoda | |
Acrilla (Ferminoscala) ? becki Durham 1937 wentletrap
Acrilla (Ferminoscala) dickersoni Durham 1937 wentletrap
Epitonium (Boreoscala) condoni Dall 1909 wentletrap Subspecies: Epitonium (Boreoscala) condoni condoni
| |
Polinices washingtonensis Weaver 1916 moon snail
"Neverita thomsonae" = Glossaulax reclusiana Deshayes 1839 moon snail
Sinum obliquum Gabb 1864 moon snail | |
Bruclarkia vokesi snail | |
Gemmula bentsonae Durham 1944 turrid | |
Exilia lincolnensis Weaver 1916 snail | |
"Molopophorus fishii" = Ancilla fishii
"Molopophorus fishii" = Ancilla fishii Gabb 1866 olive snail | |
Olequahia schencki Durham 1944 frog shell | |
Calyptraea diegoana Conrad 1855 slipper shell | |
Cylichnina turneri Effinger 1938 snail | |
Cephalopoda | |
Aturia angustata Conrad 1849 |