LOWER CRETACEOUS DEPOSITS CALIFORNIA AND OREGON

CRETACEOUS SEDIMENTARY DIVISIONS 77
cording to Martin, they occur in many, if not all, of the larger coastal
valleys. Concerning these deposits, Martin (lSSfi, p. 266} says, in part;
"A wide-spread marine transgression it) early CreUecouB time carried the sea
over most, if not nil, of the area which ia now Alaska. 1 '
Although the faunas of the early Cretaceous deposits known in Alaska
have been only partly described, there are many references in the literature
to ^liceiJa-bearing beds, including species belonging to the group of
AuceUa crasaicoUie Keyserling, sometimes accompanied by other forms
(Belemnites, Perisphincles, and Okostephanus), or by plant remains thought
to be lower Cretaceous. Not all the /luce&i-bearing rocks described
from Alaska are of Cretaceous age; some are older and are known to be
Jurassic.
Although Martin makes no mention of Knoxville beds and gives little
evidence that strata referable to this series occur there, yet, in referring
to fossil collections made from certain shales near Port Moller, he quotes
Stanton (Martin, 1926, p. 291) as including in some lots "forma related to
AuceUa piochii" (lots 5571, 5572 (part), 5576).
Whether this and other references to tbe occurrences of Aucella piochi
Gabb in the Mesozoic strata in Alaska, may be taken as evidence of the
Knoxville (late Jurassic) series there is not known; the specics may be
found to range lower. However, it appears that most, if not all, of the
references to Aucella crassicoltts Keyserling may be taken as evidence of
Lower Cretaceous (Valanginian) strata. According to Martin's account,
such Lower Cretaceous deposits occur at widely separated places in Alaska
(Herendeen Bay, Cooks Inlet, Chitina Valley, Admiralty Island, lower
Yukon, Rampart-Tanana region, Koyukuk Valley, Coville Valley, and
Innoko and Iditarod valleys).
Regarding some of the "Lower Cretaceous" deposits reported from
Alaska the records are not altogether clear; the lists of fossils from the
"Kennieott formation" in the Chitina Valley region given by Martin
(1926, p. 336-339) indicate ages ranging from upper Jurassic to upper
Albian or later. It may be possible later to divide the succession represented
in these lists into a number of distinct units.
As seen in this and other literature of Alaska most areas of Lower Cretaceous
deposits there lie in, or about, the larger valleys, or in the coastal
areas of Alaska. From these facts it may be inferred that Martin's
"marine transgression" at this epoch may have been largely confined to
its coastal borders and the larger pre-Cretaceous valleys, just as they
were in California and Oregon, and probably in British Columbia, and
that between these valleys were older mountain ranges from which the
Cretaceous sediments were derived. It may also be noted, from these