Geology Reference
In-Depth Information
(a)
(b)
(c)
(d)
(e)
(f)
Fig. 4.
Thin-section photomicrographs, plane polarized light: (a) incipient mound facies, showing local large phylloid
algal plates in mud matrix; (b) interior of phylloid algal mound with abundant early marine cement; (c) abundant phylloid
algal plates with primary pores partially fi lled with early cement and peloidal sediment and/or cement (P), blue is pore
space; (d) fragmented algal plates and abundant early marine cement, some botryoidal (B); (e) botryoidal (B) and other early
marine cements between broken phylloid algal plates; (f) low power photomicrograph showing classic distribution of algal
plates and abundant early cement. Blue is pore space.
grain-supported algal baffl estones to algal wacke-
stones and packstones with a highly variable
biotic component ranging from near monospecifi c
to a diverse normal marine faunal assemblage
(Fig. 4). Abundant primary porosity is partially
fi lled with syndepositional marine cements
(fi brous and botryoidal) as well as peloidal sedi-
ment or cement (MacIntyre, 1985). The algal facies
Phylloid algal mound facies
Throughout the Paradox Basin, in both outcrop
and in the subsurface, the phylloid algal facies
consists of phylloid algal bioherms that vary in
geometry from biostromal (fl at and elongate) to
a mound-like morphology with fl at bases. The
internal fabric of the algal facies varies from
