I9I3.] STRATIGRiVPHY OF PACIFIC COAST OF AMERICA. 603 



syncline by faulting.. An angular unconformity marked by Pholas- 

 borings may be observed in a niche of the seacliffs which form the 

 type-section of the Tunnel Point beds. 



The Aturia bed at Astoria lies in the Seattle formation. As 

 Aturia, angustata ranges through the Astoria series and Monterey 

 formation i;p and down the Pacific Coast, its value as an index- 

 fossil of a single horizon is doubtful. The term " Astoria sand- 

 stone " appears to have been intended to cover Condon's Solen Beds 

 at Astoria as well as the sandstones intercalated with the Astoria 

 shales in the steep bluffs behind the town. 



Mytihis beds ; based on a locality at the north end of Shoalwater 

 Bay (more properly Willipa Harbor), Washington, containing My- 

 tihis condoni Dall = M. middendorffi Grnk. This is the Empire 

 sandstone. 



Coos Conglomerate, basal Merced conglomerate overlying the 

 Empire beds at Coos Bay, Oregon. This is not the Coos Group of 

 Vermont geological literature which is Palaeozoic. 



J. S. Diller, 1896-1903, "A Geological Reconnaissance in North- 

 western Oregon " f' " Roseburg Folio," U. S. Geological Survey, 

 1898; "Coos Bay Folio," U. S. Geological Survey, 1901 ; "Topo- 

 graphic Development of the Klamath Mountains " f^ " Port Orford 

 Folio," U. S. Geological Survey, 1903. The Arago is recognized as 

 a division of the Tejon. Its subdivisions, the Pulaski and Coaledo, 

 appear to be of interest chiefly to the coal geologist. The Tyee 

 sandstone from the fauna at Basket Point on the Umpqua River is 

 probably the same horizon as is also the Umpqua formation. The 

 Wilbur tuft' is a lithologic phase of the Arago, a type of rock not 

 uncommon on the North Pacific Coast where fossiliferous beds rest 

 upon basic igneous flows and tuffs. 



The areas of Oakland limestone are so small that in the absence 

 of a recognizable fauna it can only be considered as a local division. 

 If post-Eocene in age, as supposed, these may represent isolated 

 San Lorenzo areas similar to those flanking the Willamette Valley. 



The relations of the Empire formation have already been con- 



^" 17th Ann. Rept. U. S. Geol. Sur., 1896, pp. 441-520. 

 ^s Bull. 196, U. S. Geol. Sur., 1902, pp. 30-31. 



