The Swan Hills Formation at the Rosevear Field in Alberta, Canada is subdivided into three major sedimentary packages (basal platform, platform reef, capping platform) that were deposited as four growth stages forming in response to changes in relative sea level. Drowning of the most basinward regions and backstepping of carbonate deposition to more landward regions resulted from episodically rising sea level.

Massive, replacement dolostone, which forms the reservoir at the Rosevear Field, is primarily restricted to the opposing margins of a marine channel that penetrates into the platform reef. Branching stromatoporoid floatstones and rudstones along the channel-margin are pervasively dolomitized and show well-developed moldic and vuggy porosity. Porosity is partially occluded by, in order of decreasing age: (1) saddle dolomite, (2) anhydrite and (3) late mosaic calcite cement. Replacement dolomite is coarsely crystalline, inclusion-rich and exhibits euhedral through anhedral textures. It postdates some low-amplitude stylolites and shallow-burial calcite cementation. Geochemically, replacement dolomite is characterized by (1) light d$\sp{18}$O values ($-$4.5 to $-$8.7$\perthous$ PDB), (2) nearly-stoichiometric composition (50.1-51.1 mole % CaCO$\sb3$) and (3) variable $\sp{87}$Sr/$\sp{86}$Sr ratios (0.7082-0.7104).

Two models for burial dolomitization are favored. In the first, fault-controlled, hydrothermal circulation of Devonian-Mississippian seawater supplies the requisite Mg for dolomitization. The second model calls upon updip fluid migration from deep basinal sources, via faults and permeable carbonate and clastic conduits, in response to the progressive westward tilting of the Western Canada Basin in the Late Mississippian through Triassic.

The overlap in d$\sp{18}$O and $\sp{87}$Sr/$\sp{86}$Sr with saddle dolomite values suggests that some replacement dolomite has recrystallized. Quantitative modeling of Sr versus $\sp{87}$Sr/$\sp{86}$Sr indicates that dolomite recrystallization proceeded in (1) dilute fluids sourced from the pre-Jurassic unconformity and (2) warm brines responsible for saddle dolomite formation.

Deep-burial diagenesis consists of saddle dolomite, anhydrite and calcite cementation. Saddle dolomite and burial calcites are characterized by radiogenic $\sp{87}$Sr/$\sp{86}$Sr ratios ($>$0.7096), T$\sb{\rm h}$ = 90-160$\sp\circ$C and T$\sb{\rm m}$ = $-$6 to $-$22$\sp\circ$C. The geochemical data is consistent with precipitation from warm brines circulating at depths of 3-5 km in the Cretaceous-Tertiary. Thermochemical sulfate reduction, commencing in the Early Tertiary, occurred during the oxidation of hydrocarbon gases.