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The basal lithology of the overlying<br />
lower Cenomanian Fish Scales Formation is a<br />
regionally extensive bioclastic conglomerate<br />
interpreted as either a wave-winnowed lag<br />
formed during a relative sea-level fall and<br />
subsequent rise, or a current-winnowed lag in<br />
deeper water. Deep-water bottom currents<br />
possibly were generated by mixing of the cool,<br />
low-salinity Boreal waters with warm, normal-salinity<br />
waters of Tethyan affinity as the<br />
Mowry Sea opened to the south forming the<br />
Western Interior Seaway (WIS). Organic matter<br />
is dominantly Type II, comprising a large<br />
component of marine algal material. The overlying<br />
barren, well-laminated sediments that<br />
comprise the bulk of the Fish Scales Formation<br />
were deposited under a stratified water<br />
column with anoxic bottom-waters and are<br />
characterized as a condensed section.<br />
The middle to upper Cenomanian Belle<br />
Fourche Formation conformably overlies the<br />
Fish Scales Formation. A regional sea-level<br />
drop occurred during Belle Fourche time as<br />
indicated by the progradation of Dunvegan<br />
deltaic sediments in northwestern Alberta.<br />
Widespread dysoxic conditions persisted<br />
throughout the middle to late Cenomanian in<br />
this region as shown by the limited agglutinated<br />
foraminiferal assemblage and sparse<br />
bioturbation. Increased detrital input is evident<br />
as an increase in silt content relative to the<br />
Fish Scales Formation and a re-introduction of<br />
significant amounts of Type III organic matter.<br />
The occurrence of numerous bioclastic conglomerates<br />
throughout the upper portion of the<br />
Belle Fourche Formation is possibly the result<br />
of relative sea-level drops affecting areas of<br />
different water depth with variable erosional<br />
intensity.<br />
Maximum transgression in latest Cenomanian<br />
to early Turonian time brought fully marine<br />
conditions and planktic Tethyan fauna<br />
into the Canadian portion of the WIS. This<br />
time period is represented by the Second<br />
White Specks Formation. Productivity in the<br />
upper water column was high and anoxic bottom<br />
waters preserved abundant Type II organic<br />
matter.<br />
Lateral facies variations and a diachronous<br />
introduction of Tethyan foraminifera and<br />
coccoliths to various parts of the basin indicate<br />
pathways of oceanic circulation. The influence<br />
of major Cordilleran detrital sources<br />
limited pelagic faunal development in the west.<br />
A significant unconformity in central Saskatchewan<br />
indicates local basin floor doming<br />
and subsequent erosion in late Turonian to<br />
Santonian time.<br />
2008010055<br />
巴 黎 盆 地 早 白 垩 世 铁 质 鲕 粒 : 土 壤 起 源 对 海<br />
洋 起 源 及 它 们 的 古 气 候 意 义 = Early Cretaceous<br />
iron ooids in the Paris Basin: pedogenic<br />
versus marine origin and their palaeoclimatic<br />
significance. ( 英 文 ). Taylor K G. Cretaceous<br />
Research, 1996, 17(1): 109-118<br />
Oolitic ironstones occur within the subsurface<br />
Lower Cretaceous sediments of the Pays<br />
de l’Ourcq region of the Paris Basin. Goethite<br />
ooids in these ironstones are of three types.<br />
Type 1 ooids are characterized by welldeveloped<br />
concentric lamination and the absence<br />
of a clear nucleus. Type 2 ooids are<br />
characterized by thin, concentrically laminated<br />
cortices and nuclei of iron oxide or quartz<br />
grains. These nuclei show structures (iron oxide<br />
veining in quartz grains, iron oxide platelets)<br />
similar to that formed within lateritic<br />
soils. Type 3 ooids are small, generally lack<br />
concentric lamination and commonly contain<br />
‘desiccation ’ features. The goethite in the<br />
ironstones has negligible Al-substitution, indicative<br />
of formation in the marine environment.<br />
It is proposed that the ooids formed<br />
through accretion on the sea-floor, or just below<br />
the sediment surface. However, the nuclei<br />
of type 2 ooids, and many of the detrital grains<br />
within the ironstones, were derived from lateritic<br />
soils upon nearby massifs. Therefore,<br />
evidence is present within the ironstones for a<br />
warm, sub-tropical climate during the Early<br />
Cretaceous, although the process of oolitic<br />
ironstone formation was most likely controlled<br />
by marine sedimentary processes rather than<br />
climate.<br />
2008010056<br />
贵 州 中 寒 武 世 凯 里 生 物 群 中 纳 罗 虫 ( 节 肢 动<br />
物 门 ) 的 埋 葬 学 = Taphonomy of Naraoiids<br />
(Arthropoda) from the Middle Cambrian Kaili<br />
Biota, Guizhou Province, South China. ( 英 文 ).<br />
Lin J P. Palaios, 2006, 21(1): 15–25 Naraoiids<br />
in the Kaili biota (Taijiangian Stage,<br />
Wulingian Series, lower Middle Cambrian)<br />
are preserved in a variety of taphonomic states.<br />
Decomposition, entombment, and fossil<br />
diagenesis of Kaili naraoiid specimens (n = 69)<br />
are described. The decay rates of appendages,<br />
internal organs, and dorsal sclerites are different,<br />
and should be treated as separate taphonomic<br />
elements. A classification scheme<br />
to delineate the preservational states is proposed<br />
here to distinguish carcasses from molts<br />
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