Geological Setting of the Newell County Field Research Station
The Field Trip occurs within Great Plains physiographic province, which is coextensive with autochthonous Interior Platform Structural Province, underlain by Middle Proterozoic to Tertiary stratigraphic successions of Western Canada Sedimentary Basin (WCSB, Figure 1). To the west lies Cordilleran Structural Province, an allochthon, the sedimentary successions of which are composed of deformed WCSB strata that underlie the Foothills and Front Ranges of the Rocky Mountains.
Figure 1: General features of the Phanerozoic sedimentary successions in the vicinity of the Bow River valley.
The WCSB succession thickens westward, in part, through the addition of older stratigraphic successions at its base in the allochthon, and in part, due to syn-depositional tectonic processes that increased accommodation space westward during periods of subsidence. Front Range and Foothills deformation tectonically shortens and thickens the WCSB, primarily along eastward directed thrust faults, fault bend folds and cylindrical folds that juxtapose older WCSB successions onto younger strata. The underlying Precambrian basement is autochthonous. The timing of the deformation becomes progressively younger eastward. Exact timing of displacements on individual structures is not tightly controlled. However, stratigraphic juxtapositions across major thrust faults suggest that motion on major Front Range thrusts occurred during or continued after the deposition of Campanian Belly River Group, which forms the FRS storage complex. Phanerozoic successions are composed of several westwardly thickening sedimentary sequences that approximate the classical North American sedimentary sequence defined by Larry Sloss:
- A Lower Cambrian to Silurian clastic and carbonate succession typified by “Grand Cycles” of sedimentation approximating the Sauk and Tippecanoe sequences that is attributed to Paleozoic passive margin formation.
- A middle Devonian and Carboniferous predominantly carbonate succession that approximates Kaskaskia sequence linked to little preserved Ellesmerian and Antler orogenic contraction on the Paleozoic passive margin.
- A commonly thin, but westwardly significant, Carboniferous to Lower Jurassic sequence of uncertain tectonic affinities equivalent to Absaroka sequence.
- A predominantly coarse clastic Middle Jurassic to Lower Cretaceous succession, accompanying a classical geosynclinal orogenic signal, derived primarily from the impinging Cordilleran orogen like lower Tejas Sequence. This foreland basin drained northward to shorelines on a Boreal Ocean and is known as the Foreland Basin of Columbian orogeny.
- A predominantly fine clastic upper Lower Cretaceous to upper Paleocene succession, also derived from the Cordilleran orogen, that forms the Laramide Foreland Basin succession within the North American Cretaceous Interior Seaway that connected to the Atlantic margin via Gulf of Mexico.
- Low relief localized erosional valleys, and eastwardly lower elevations conceal a profound westwardly increasing erosion, probably mid-Eocene and younger, from thermochronology, coalification and organic maturity profiles. At Dinosaur Park the eroded thickness is estimated to be between 2-2.5 km, on the west side of Calgary it is ~3.8 km, and in the Rocky Mountain Front Ranges it is ~8 km thick.
The FRS is constructed within Upper Cretaceous parts of the Laramide Foreland succession including Campanian Bearpaw Fm. and Belly River Group that are underlain by Upper and Lower Cretaceous Colorado Group, predominantly shale. The preserved Phanerozoic succession is about 4 km thick below the University of Calgary and about 2.3 km thick in the vicinity of Brooks. It is an uplifted, deeply eroded and glacially modified landscape that declines eastward from 1115 m at the University of Calgary to 712 m at Dinosaur Provincial Park.
Palliser Triangle Environment
Palliser Triangle, named for Captain John Palliser, is a geographic region overlying southern WCSB. Originally. part of Rupertsland (Hudson Bay C. 1670-1869), it was purchased by the Dominion of Canada (1870; £300,000 or CDN $2.3 billion in 2023). Originally, mixed grassland in the North American Great Plains, it is a currently semi-humid to semi-arid steppe. It coincides with a brown soil region that is agriculturally important, and underlain by earth resources, primarily petroleum, coal and potash and Canada’s nascent lithium brine extraction industry.
Figure 2: Palliser Triangle as variously defined.
Palliser Triangle populations and agriculture rely primarily on surface water derived from regional snowpack and precipitation in the Rocky Mountain Front Ranges for potable, agriculture, and industrial water. During the Last Glacial Maximum, Laurentide (Continental) and Cordilleran ice sheets met near the University of Calgary campus. Melting ice sheets impounded glacial Lake Calgary (~11,000 yr to ~8,100 yr. BP).
Surface water recharge through glacial deposits, with different erratic provenance produces different groundwater. In regions covered by Cordilleran ice groundwater generally has low TDS Ca-HCO3, where erratics are predominantly Paleozoic carbonate rocks. Tills below Laurentide Ice commonly contain Canadian Shield pyritic tills resulting high TDS, high Na-SO4 groundwater like that at the FRS. As we drive to the FRS, you will see irrigation canals, as well as a myriad of saline to hypersaline lakes and sloughs typical of the low relief plateau between the major incised river valleys, notably Bow and Red Deer rivers east of Calgary.
Mean temperature has increased ~1oC over the past 105 years (Winnipeg) mostly due to milder winter temperatures and less snow cover. Precision temperature logs to several hundred meters depth show average ground surface temperatures exceed surface air temperature increases that are up to 2.1 C. due to land use changes, while native grassland sites more closely agree with the recorded SAT change. The same studies identified a “Little Ice Age” signal in the shallow borehole temperature anomaly in Palliser Triangle, suggesting “Little Ice Age” cooling was more widespread than acknowledged by the IPCC.
Palliser Triangle climate inferences from lake sediment core studies illustrate three major post-glacial climate episodes including: a mid-Holocene warm interval, the Neoglacial, the Medieval Warm Period and the Little Ice Age. The Early Holocene period prior to 7500 yr. BP was a dynamic time that lacked subtle changes typical of the atmospherically forced climate record observed in the last two millennia of lake cores and the last century of meteorological data. During the Mid-Holocene, 7500 – 4000 yr. BP, many of the larger lakebeds appeared to have been completely dry, either intermittently or for protracted periods. This indicates a general period of extreme aridity compared to times prior or since. Lake levels were inferred at least 4 m lower than present levels for much of the mid-Holocene. After 4000 yr BP the current sub-humid to semi-arid and highly variable climate became manifest. The best climate signal was inferred from the last 2000 years of lake core records. This period is when atmospheric forcing is inferred the predominant cause of climate variability. Still much greater and lesser aridity, compared to the historically recorded is recorded in the lake cores.
A major contribution of the lake core project was the identification that the local Historical Period.
Newell County Field Research Station Wells
Figure 3: Well location diagram for water deep injection and observation wells plus water wells and FRS.
The FRS is on an approximately 200 hectare site. The FRS is not a CCS storage project primarily. It is a containment and conformance science and technology demonstration and development site where CO2 is injected from above to simulate leakage from a CO2 storage complex below. Operating up to 550m deep, the FRS provides, among other things, opportunities to perform large-scale gas phase injected CO2 studies in the overlying shallow Upper Cretaceous Interior Seaway stratigraphic successions that are a major North American geological feature.
The injection well (CMCRI Countess – 100/10-22-17-16W4; 50°27’1.52″N, 112° 7’14.44″W) is drilled to 550 mKB. It is “plugged back” to 305.5 metres below drilling rig kelly bushing (mKB) and perforated 295 – 302 mKB (Figure 13). Injection well surface casing extends to 226 mKB , at the base of the groundwater protection zone. The injection well deep casing includes intervals of chrome steel over two possible injection intervals. Through and below the surface casing a CO2 resistant cement is placed in the well bore annulus between the deep casing string and either the surface casing or the bedrock. Like all wells administered by the Alberta Energy Regulator (>150 m), the FRS injection and deep monitoring wells are equipped with surface casing vents (SCV).
Two 350 mKB deep monitoring wells were constructed, respectively, 30 m up-dip or northeast, and 20 m down-dip or southwest of the injection well. The up-dip well (CMCRI Countess 103/10-22-17-16W4M; 50°27’2.20″N, 112° 7’13.35″W) is instrumented and completed primarily to perform geochemical sampling and monitoring experiments. Two notable features of this well are its completion using a sand pack and screened casing intervals over the injection zone interval and the installation of a U-Tube subsurface fluid sampling device within the sand pack. The down-dip well (CMCRI Countess 102/10-22-17-16W4; 50°27’1.06″N. 112° 7’15.14″W) is instrumented and completed primarily to perform geophysical monitoring experiments (Lawton et al., 2019). Respectively the two monitoring wells have steel surface casing that lands at 120 mKB and 50 mKB,
Six water wells (<150 m) were completed to the south, east, southeast and southwest of the three deep wells (Figure 13). The first water well drilled, DW1 (Figure 13; 50°26’56.04″N, 112° 7’19.86″W), is constructed like a domestic or farm well. It is drilled to 85.3 m below the ground surface (mbgs) and completed with a combination of a steel surface casing (0-26.2 mgbs) in unconsolidated Pleistocene tills and glacial-fluvial sediments that lands in the bedrock succession and an acrylonitrile butadiene styrene (ABS) thermoplastic casing (24.3 – 45 mbgs) that is slotted between 27.4 – 30.5 mbgs), such that water production is comingled from several sandstone beds across the slotted interval. This well contains an electrically powered submersible pump. The two other water wells, ML-2 (Figure 13; 50°26’55.92″N, 112° 7’19.32″W) and ML-3 (Figure 13; 50°27’0.14″N; 112° 7’12.72″W) are drilled to 85.3 mbgs and 108.2 mbgs, respectively.
Two water wells are completed with, Westbay and G360 multilevel groundwater monitoring systems.