Page 197 - Carbonate Facies in Geologic History

184 Pennsylvanian-Lower Permian Shelf Margin Facies

tan
9,al"slonl.75 % Clear Waler
h.otn BC -15 0/0) Shooling
• b,own. ,usly Phose
.I"nql"
OOLITE
SUBPHASE
tan clott.d and
pIII,t.d .
gry.

nodula,
9'Y- ,... ,....
brn
gx,
Normal
, nodula' ft Morine
gry.- Phose
b,n . , ro "' " burrowtd

g,n .

B89inning
Clasllc
Phose
g', _.r. e::,. wo,n bloclosh
brn . I.;·~"";;;::"-Lo."';"'·;'!_COlc " .A..qIZ . gnl.

CQ] Cold_ ! ,..~ 1 EdgewlS! eonglomeralls_ pIeces up to severo l em._
~ C"noid _ IOQ 1 U l hoelosts of a few mm Slze _
t: '" '1 Pellel S ond shelly blotla sts - (ZE Tubular foram inlfero and chomb".d fo,amlnlfera _

Fig. VI-12. Virgilian cycle 10 m thick, on south wall, near mouth of Beeman Canyon, Sacra-
mento Mountains, New Mexico. Algal plate mounds typically develop in clotted-pelleted
foraminiferal strata just beneath oolitic phase of cycle. From Wilson (1967 a)

Little dolomitization occurs in such reservoirs except in the Aneth field of the
Paradox Basin. Indeed, the cause of porosity is different in the Aneth field where a
thick lime sand top is partly dolomitized and where considerable primary poros-
ity is preserved within a framework of winnowed algal plates and pelleted mud
lenses.