West-central Saskatchewan Research Articles

Abstract: Sequence Stratigraphy and Stochastic Reservoir Modelling of an incised valley fill reservoir in the Lower Cretaceous Mannville Group, West Central Saskatchewan 

Abstract: Sequence Stratigraphy and Stochastic Reservoir Modelling of an incised valley fill reservoir in the Lower Cretaceous Mannville Group, West Central Saskatchewan 

Evaluation of Emulsified Solvent Flooding For Heavy Oil Recovery

Abstract Efficient secondary and tertiary recovery of heavy oil from thin reservoirs, such as those in the Lloydminster area, remains an unsolved challenge to IOR researchers. The primary recovery from these heavy oil reservoirs is generally poor (often less than 5% of original oil in place) and waterflooding is rather inefficient due to very adverse mobility ratio which results in severe viscous fingering and early water breakthrough. Thermal methods are also not viable due to excessive heat losses to the underlying and overlying formations. Non-thermal techniques involving injection of a miscible solvent are uneconomical due to the high cost of solvent in relation to the market value of the heavy oil recovered. Therefore, there is a need for novel processes designed specifically for such reservoirs. This paper presents an experimental evaluation of the use of emulsified solvents to recover heavy oil from thin reservoirs. The emulsified solvent flooding can potentially provide the high recovery efficiency of miscible solvents at a fraction of the cost. The process, if successful, would have wide application in thin heavy oil reservoirs. Commercially available emulsifiers were used to formulate solvent-in-water emulsions using natural gas condensate or petroleum naphtha as the solvent. The oil recovery potential of these emulsions was evaluated in one metre long linear sandpacks and in a three-dimensional glass-bead packed visual model. Effects of various process variables, including: solvent volume fraction; surfactant concentration; flow velocity; and oil viscosity, on oil recovery performance were experimentally evaluated. The results show that the emulsified solvent flooding provides significantly superior displacement efficiency compared to straight solvent injection and waterflooding. The mechanisms responsible for such high efficiency include:reduction in oil viscosity due to dilution by the solvent;mobility control provided by the trapping of emulsion droplets at pore throats; andin situ emulsification of the oil being displaced. The relative importance of these mechanisms was evaluated under different conditions. An economic analysis showed that, although the process can recover a large fraction of the oil in place, it would not be profitable under current price conditions. Several novel ideas for improving the performance are suggested. Introduction Vast reserves of heavy oil which can be mobilized at reservoir conditions exist in the Lloydminster area of east central Alberta and west central Saskatchewan. Although the oil in these reservoirs is mobile, its production is hampered by high viscosity and the primary recovery is typically between 5 – 10%. Enhanced recovery by steam injection is generally not profitable in these relatively thin reservoirs because of the excessive heat losses to the surrounding rock formations. Non-thermal techniques involving injection of a miscible solvent are also uneconomical due to the high cost of solvent in relation to the market value of the heavy oil recovered. Therefore, new recovery processes are needed to economically recover the heavy oil from these reservoirs. One attractive alternative to miscible solvent injection appears to be the Emulsified Solvent Flooding process. It has the potential to provide the high displacement efficiency of a miscible flood ata significantly lower cost due to the reduced solvent requirements.

Implications of late fall and early spring 2,4-D applications on subsequent canola production on Black, Dark Brown and Gray Wooded Soil

Late fall or early spring application of 2,4-D to control winter annual weeds prior to canola has not been recommended as the herbicidal effects on canola growth and development on varying soil types are not well defined. 2,4-D was applied to Black, Dark Brown and Gray Wooded soils located in west-central and northwest Saskatchewan. Applications were made in the fall and early spring prior to planting Brassica napus L. and Brassica rapa L. canola from 1992 to 1994 at the recommended (0.42 kg ha−1) and twice the recommended rate. The rate of 2,4-D applied had no effect on canola plant population, pods per plant, yield, green seed, chlorophyll, kernel or test weight. Application of 2,4-D in the fall had no effect on any variable while spring application reduced plant stands and increased green content but had no effect on pod production, yield or chlorophyll content. Late fall application of 2,4-D prior to canola in rotation should be recognized as a valuable addition to weed management in canola, particularly when direct seeding is practised. Key words: Canola, 2,4-D, soil residual, injury

Use of Incorporated and Non-incorporated Granular Trifluralin for Annual Grass Control in Barley (Hordeum vulgare), Wheat (Triticum aestivum), and Canola (Brassica napus)

The comparison of incorporation vs no incorporation on a mid-October application of the granular formulation of trifluralin to control infestations of wild oat and green foxtail was evaluated in spring barley, wheat, and canola in west central Saskatchewan over a 3 yr period. Incorporation treatments consisted of: no incorporation, one incorporation in fall, one incorporation in fall and a second in spring, one incorporation in fall and two additional incorporations in spring. All treatments eliminated green foxtail. In all three crops wild oat panicle counts were equivalent from incorporated and non-incorporated trifluralin. Wild oat fresh weights in crops grown on stubble were similar for incorporated and non-incorporated trifluralin. In fallow crops, wild oat fresh weight reductions were greater in three of nine site years with incorporation. There was little difference in crop yields from incorporated and non-incorporated trifluralin.

The Red Fox Invasion and Other Changes in Wildlife Populations in West-Central Saskatchewan Since the 1960s

The Red Fox Invasion and Other Changes in Wildlife Populations in West-Central Saskatchewan Since the 1960s

Economics of monoculture cereal and mixed oilseed-cereal rotations in west-central Saskatchewan

The effects of product price and input cost on the economic performance and riskiness of nine cropping systems were assessed over a 12-yr period on a Dark Brown Chernozemic loam to clay loam soil at Scott, Saskatchewan. The rotations included two 2-yr fallow (F)-crop systems with hard red spring wheat (W) (Triticum aestivum L.) and canola (C) (Brassica campestris L.), four 3-yr fallow-containing rotations with combinations of wheat, canola and barley (B) (Hordeum vulgare L.), a 4-yr and a 6-yr rotation that included alfalfa (Medicago sativa L.) hay, and continuous wheat. All crops were fertilized with rates of N and P based on general guidelines for the region, except for forage hay which was unfertilized. Four rotations (F-C, F-C-W, F-C-B, and F-W-W) showed good economic and risk performance under most price scenarios. The F-W and F-W-B rotations generally ranked intermediate, averaging about 11% lower in net return than the best systems at 1994 commodity price levels; however, at grain prices lower than 75% of these values, net returns were highest with F-W and F-C. It was profitable to substitute canola for wheat grown on fallow when the ratio of canola price to wheat price exceeded 1.8, and to substitute barley for wheat grown on stubble when the barley/wheat price ratio exceeded 0.75. Including alfalfa hay in the rotation was profitable only when the hay/wheat price ratio exceeded 0.8. The unit cost of producing wheat averaged $91 t−1 when grown on fallow, $106 t−1 when grown on canola stubble, $116 t−1 when grown on wheat stubble in fallow-containing rotations and $133 t−1 when grown on continuous wheat stubble. Similarly, the cost of producing barley averaged $74 t−1 when grown on canola stubble and $83 t−1 on wheat stubble. We concluded that producers in the Dark Brown soil zone of west-central Saskatchewan have a strong economic incentive to diversify crop rotations away from traditional monoculture cereal to mixed oilseed-cereal systems. Key words: Wheat, canola, barley, hay, production costs, net returns, riskiness

Application of a bioeconomic strategic planning model to an industrial forest in saskatchewan

Contemporary approaches to the issue of the allocation, conservation and management of forested land require forest managers to demonstrate the sustainability of the flow of economic, ecological and social benefits accruing from industrial use of forest resources. The integration of data sets defining these disparate resource benefits requires that they be expressed in commensurate terms such that trade-offs can be undertaken in the search for a management strategy which provides a publicly acceptable mix of benefits. To accomplish this, a new optimisation model was developed and tested for a 1.7 Mha commercial forest in west central Saskatchewan, and then used to develop 8 different forest management alternatives which were then subjected to formal evaluation procedures leading to the selection of a preferred forest management alternative.

Stratigraphy And Depositional Environments of the Bakken Formation (Upper DevonianILower Mississippian) In West-central Saskatchewan

Abstract The Upper Devonian/Lower Mississippian Bakken Formation of west-central Saskatchewan comprises three members: the lower black shale member (LBSH), the middle sandstone member and the upper black shale member (UBSH). Seven different facies have been defined in the middle sandstone member:oolitic bioclastic grainstone facies (OBG);lower bioturbated siltstone facies (LBS);thinly-bedded bioturbated sandstone facies (TBBS);thinly-bedded sandstone facies (TBS);interbedded sandstone-siltstone-shale facies (ISSS);upper bioturbated siltstone facies (UBS);transitional facies (CSST). The upper black shale member (UBSH) is a facies equivalent of facies six and seven in the middle member. During the early stages of deposition of the Bakken Formation, the basin waters were relatively deep and the lower Bakken shale member (LBSH) was deposited below storm wave-base under anoxic conditions. Shallowing before, or at the beginning of middle Bakken deposition resulted in the development of oolitic shoals (OBG) in a shallow, open marine setting and fine-gniined siliciclastic sediments (LBS) accumulated basinward of the shoals. Subsequent deepening of the basin waters was accompanied by progradation of terrigenous sediments. These were distributed and reworked by storms and tidal currents (TBS, TBBS and ISSS), ultimately burying the oolitic shoals. Late Middle Bakken deposition was marked by continued basin deepening with possible localized brackish or lagoonal conditions (CSST) and open marine offshore shelf conditions (UBS). With continued transgression, sediment supply was reduced and sediments remained in flooded river-valley systems. The upper Bakken shale member represents basin deepening coincidental with transgression, sediment starvation and a return to anoxic marine conditions (UBSH) similar to, but less widespread than those of the lower Bakken shale. Introduction The Upper Devonian/Lower Mississippian Bakken Formation is a predominantly siliciclastic, marine unit in the subsurface of the Williston Basin and parts of southeastern Alberta. In west-central Saskatchewan the Bakken Formation varies from 0 to more than 31 m thick. The original depositional thickness commonly is not represented as a result of sub-Cretaceous erosion. In the study area. Bakken strata unconformably overlie the Big Valley Formation. They are unconformably (locally conformably?) overlain by the Lodgepole Formation, or are unconformably overlain by Cretaceous sands or the Success Formation (JurassicCretaceous?). The Bakken Formation has long been a useful marker unit because of its distinctive log signature. Recently, oil has been successfully recovered from the formation by horizontal drilling(1). Oil is produced in southeast and west-central Saskatchewan, the area of this study (Figure 1), and in southwest Manitoba. The Bakken Formation has been subdivided into three informal Member (2), all of which are recognized where the Bakken has been identified. They are the Lower black shake member, the middle sandstone member, and the upper black shale member (Figure 2). The purpose of this paper is to describe the Bakken facies and associated rock-types in west-central Saskatchewan (Figure 1) using evidence from the study of about 50 cores and associated well-log data, and to make a preliminary interpretation of the depositional history of the formation in the study area.

Efficacy of Fall Incorporated and Non-incorporated Granular Triallate on Wild Oat (Avena fatua) and Wheat (Triticum aestivum)

The influence of incorporation vs no incorporation on the efficacy of granular triallate applied in mid-October at 1400 and 1700 g ai/ha to control wild oat was evaluated in spring wheat in west central Saskatchewan over a 7-yr period. All fall-applied triallate reduced wild oat panicles and fresh weight, and increased yield compared to untreated checks. With applications in standing wheat stubble there was no difference in wild oat control from incorporation versus no incorporation. All triallate treatments reduced wild oat panicles and fresh weight by over 95%, and resulted in wheat yield increases ranging from 29 to 67%. In tilled fallow, incorporated granules provided better wild oat control than when there was no incorporation. Wheat yield increases ranged from 50 to 85% for triallate treatments with yield for incorporated triallate approximately 15% greater than non-incorporated. The rate of triallate did not affect the level of wild oat control achieved with either incorporation method. In separate tolerance studies triallate incorporation method did not affect spring wheat emergence or subsequent development.

Depths, rates and dates of seeding and yield of yellow mustard (Sinapis alba L.) in west-central Saskatchewan

From 1984 to 1989, studies were conducted to evaluate the effects of depths, rates and dates of seeding on yellow mustard (Sinapis alba L.). As seeding depth was increased, emergence and development to maturity were delayed and plant densities were decreased. Seeding at 12- or 25-mm depths resulted in 4-year average yields of 1447 and 1424 kg ha−1 respectively, whereas seeding at 50 or 75 mm gave yields of 1177 and 987 kg ha−1, respectively. Where the soil was too dry to support germination at 25 mm, seeding at depths up to 50 mm gave similar yields to seeding at lesser depths. Seeding at 4 kg ha−1 reduced yields compared with seeding at 8, 12 or 16 kg ha−1 when averaged over 6 yr. As seeding rates increased, a lower proportion of seedlings emerged and developed into mature plants, apparently due to increased competition between plants. Increasing rates of seeding reduced the number of branches and pods produced per plant and decreased the number of days to mature. Seeding between 1 May and 26 May had only a small impact on yields in most years; however, further delays in seeding decreased yields substantially. As seeding was delayed, the number of days from seeding to emergence and to maturity decreased, and deviations from this trend were usually associated with periods of cool wet weather.Key words: yellow mustard, Sinapis alba, seeding depth, seeding rate, seeding date

Stratigraphy and Diagenesis of the Bakken Formation, West Central Saskatchewan

Stratigraphy and Diagenesis of the Bakken Formation, West Central Saskatchewan

Depth-Related Oil Viscosity Variation In Canadian Heavy Oil Reservoirs

Abstract The natural variability of oil viscosity in the Clearwater B heavy oil formation in east central Alberta has been examined. Oil samples taken from preserved cores from various depths vary in viscosity by as much as tenfold. The data show a consistent trend of increased viscosity with increased depth of origin of the sample. Furthermore, over an area of 16 sections oil viscosity appears to correlate with structural elevation. Samples from similar absolute elevations have similar viscosity. In location where the reservoir is structurally high, the viscosity-depth profile shifts toward less viscous oil, and, in structural lows, the profile shifts to more viscous oil. Distillation curves of selected samples confirm that the oil viscosity variations coincide with compositional differences. Single sets of samples from three other heavy oil reservoirs, the McMurray and Wabiskaw in the Caribou Lake area, and the Waseca sand at Pikes Peak in west central Saskatchewan, show similar trends to increased viscosity toward the bottom of the reservoir sand. These observations are compared with others reported in the literature, and possible causes of these compositional variations and of their significance to thermal recovery processes are discussed. Introduction Variations in oil viscosity and composition were first observed during studies of oil produced from wells in a thermal project near Lloydminster, Saskatchewan. Although much of the variation could be attributed to alteration resulting from the thermal recovery process, some of the compositional data suggested that the unaltered "native" oil may not be as homogenous as was assumed. Other data (density, viscosity and distillation) for samples produced under primary conditions from other reservoirs in the Lloydminster area, also gave indication that significant viscosity variations occur from well to well within the same reservoir. Because variability of oil viscosity within a reservoir could impact on the success of a recovery process, and could also affect assessment of the value and amount of recoverable oil, it was of interest to conduct a more thorough study to confirm the extent of variability in heavy oil reservoirs. The opportunity to conduct such a study in a virgin reservoir area came in 1987 when Husky Oil and Alberta Energy Company carried out extensive drilling and coring of an area in the Caribou Lake block of east central Alberta. This paper reports on a detailed examination of oil variability within the Cleanwater ‘B’ reservoir, in particular in the Caribou Lake area held jointly by Alberta Energy Company and Husky Oil Operations. Literature Review Although the subject has received little attention in Canada, oil variability within individual reservoirs has been observed in many reservoirs throughout the world. Hunt(l) sites a number of examples, including the Coalinga field in California, the Lagunillas field in Venezuela, the Sakhalin field in the U.S.S.R., and the Burgan field in Kuwait which show dramatic variations in oil viscosity and density with location and/or depth. An early discussion of the Kuwait oil fields and the implications of oil heterogeneity was given by Hetherington and Horan(2).

The Keg River/Winnipegosis Petroleum System--Source to Trap Part I

The Keg River/Winnipegosis Formation is a heterogeneous hydrocarbon system composed of three oil families based upon gas chromatography of extracts from nine potential source rocks, six oil stained cores, and oils from fourteen Keg River/Winnipegosis fields. Family 1 - The 'pinnacle' play oils (North Alberta, South Saskatchewan, and North Dakota), together with Virago field (Southeast Alberta), comprise a locally sourced (upper Keg River/lower Muskeg/Ratner) family that exhibits a broad maturity range heavily dependent upon present burial depths and geothermal gradients. Family 2 - Oils from Utikima Lake, Peerless, Panny, and Senex fields in Alberta are a homogeneous, migrated oil sourced from the Duvernay Formation (upper Devonian). Family 3 - Oils from Temple field (North Dakota) and oil-stained carbonate cores of west-central Saskatchewan are of unknown source (possibly mixed Ordovician and Devonian or Mississippian). Long-distance (> 200 mi or > 320 km) oil migration routes through the thermally immature Keg River carbonates of Northeast Alberta were tracked by epi-fluorescence (E-F) study of 200 thin sections. Drill stem test (DST) recoveries and E-F oil shows demonstrate that oil migration extended northeast of the Senex area to the Keg River shelf margin. Oil migration along the shelf margin was southeast, oblique to regionalmore » structural dip. E-F shows in shelf margin strata continue southeast to the Cold Lake Weapon Range where a pre-Cretaceous dissolution event removed the overlying Muskeg halite seal. Porous carbonates of the Keg River shelf margin were possibly a migration route for oils sourcing the Cretaceous Athabasca oil sands overlying this dissolution area.« less

Ice-thrust features and the Maymont landslide in the North Saskatchewan River valley

The Battleford glacier created shearing and softening of bedrock clays, contributing to widespread slope instability along the valley of the North Saskatchewan River. The Battleford glacier flowed southeastward down the valley of the North Saskatchewan River during its final stage in west-central Saskatchewan. It created flutings, crevasse fillings, folding and faulting in ice-thrust ridges, and extensive horizontal gouge zones filled with soft, malleable clay. Extensive drilling and testing for the foundations of the Maymont bridge provided definitive data outlining at least three gouge zones. The shallowest gouge zone at an elevation of 465 m defines the base of the most severe glacial folding and deformation of the bedrock in at least one of the ice-thrust ridges. The deeper gouge zones are at about 433 and 438 m elevation. Postglacial landslides (slumps) along the southern side of the North Saskatchewan River are controlled by the gouge zones, which are low-friction slide surfaces along which large horizontal movements took place. Multiple normal faults and graben structures in the landslide mass could have been the mechanism for horizontal movement and extension with little or no rotation. Two main slide masses have been identified: the lower one moved on the middle gouge zone (438 m), and the upper one moved on the upper gouge zone (465 m).

Viking Formation (Albian) at Eureka, Saskatchewan: A Transgressed and Degraded Shelf Sand Ridge (1)

The Viking oil field at Eureka is part of the long (80 km), narrow (10 km) east-west-trending Dodsland-Hoosier offshore sand ridge in west-central Saskatchewan. The various facies of the ridge are encased in marine mudstones, and the ridge has formerly been interpreted as a tidal current deposit. However, core examination shows that the facies are burrowed and bioturbated and very few primary sedimentary structures are preserved. The sandstone facies are extensively bioturbated by Teichichnus, and contain no medium-scale cross-bedding, and no other tidal features such as reactivation surfaces, spring-neap cycles and tidal bundles. Cross sections constructed from well logs and cores demonstrate that the ridge overlies an erosion surface, and that at least three other erosi n surfaces occur within the sand body. These surfaces strike east-west, and dip very gently southward. Pebble veneers occur in patches on the erosion surfaces. We interpret the ridge as having formed from a plume of sand in a shallow sea, with its western end close to a deltaic distributary channel (similar to the plume east of the modern Nile delta). The regional Viking shoreline moved north or northeastward into the basin during a lowstand of relative sea level. During subsequent transgression, the delta was eroded and displaced an unknown distance southwestward. The ridge also shifted southward, and was finally detached from the distributary and abandoned on the shelf. Original slopes of the southern ridge margin were flattened to gradients of 0.0006-0.0009 by storm-generated currents. The internal erosion surfaces were probably formed during the overall transgression. Rates of sediment movement were relatively slow, resulting in almost c mplete bioturbation and, hence, destruction of primary sedimentary structures.

Assessment of soil erosion in west-central Saskatchewan using cesium-137 : Kiss, J J; De Jong, E; Rostad, H P W Can J Soil SciV66, N4, Nov 1986, P561–600

Assessment of soil erosion in west-central Saskatchewan using cesium-137 : Kiss, J J; De Jong, E; Rostad, H P W Can J Soil SciV66, N4, Nov 1986, P561–600

Development Of Heavy Oil And Natural Bitumen In Western Canada

Abstract Activity in Alberta and Saskatchewan heavy oil and bituminous sands regions is widespread with projects of sufficient number and scope to produce a significant quantity of heavy oil and bitumen. This paper describes in general terms the location and nature of several projects in each of the prime developmental areas, with special attention to the drilling, production and transportation methods developed. Although numerous new commercial scale projects were expected to proceed in 1986, the drop in crude oil prices and shortage of cash flow since early 1986 has resulted in several postponements. The two oil sands mining projects in the Athabasca deposits continue operation with major efforts to reduce cost and defer projects for increased production. The vast resources of the area have been defined, the development of recovery technology and production systems is well advanced. Significant new production from these deposits will not be achieved until crude prices stabilize at levels above the recent U.S. $14 – $15 experienced. Introduction In Western Canada, resources of heavy oil and natural bitumen occur primarily in west-central Saskatchewan and northeast Alberta. Alberta's resources are the most significant in ultimate potential. The resources occur primarily in widespread Cretaceous sands with some potential sources in underlying carbonates. The crude oil is generally of heavy gravity 20 ° – 25 ° API in the south-east deposits and transitions to natural bitumen of 8 ° – 12 ° API in the northwestern deposits. Recovery methods span the entire technical and operational spectrum from near conventional through various thermal and other in-situ methods, to the oil sands mines in the Athabasca deposits. Production of raw bitumen and heavy oil exceeds markets available in Canada. A well developed transportation and marketing system delivers most of the crude to the U.S. markets primarily in PADD II (Illinois, Indiana, Michigan, Minnesota, Ohio, Wisconsin). The emerging technology in recovery is supported by advanced technology in the application of slant well drilling, horizontal well drilling, and innovative water source and re-use methods. The price collapse of 1986 has caused the heavy oil and bitumen programs to be re-evaluated and, in many cases, delayed or reduced in scope. The certainty that remains for the industry is that an abundant resource has been defined over a vast area, technology has been established or is in advanced development to exploit these resources, and the fiscal and administrative policy of the governments is supportive of heavy oil and bitumen development. Occurrence of Heavy Oil and Bitumen The deposits of heavy oil and bitumen in western Canada, primarily in Alberta, are among the largest known in the world. The classification as bitumen or heavy crude oil used in this paper conforms with the practice in Alberta which defines natural bitumen as a viscous mixture of heavy hydrocarbons which, in its naturally occurring state, will not flow to a well. Heavy crudes are those mixtures which may flow naturally and have density greater than 900 kg/m3. For ease of reference, Alberta has adopted a geographic nomenclature for the bitumen deposits as Peace River, Athabasca, and Cold Lake (Fig. I).

AN ASSESSMENT OF SOIL EROSION IN WEST-CENTRAL SASKATCHEWAN USING CESIUM-137

Soil erosion in five Rural Municipalities of west-central Saskatchewan was assessed using cesium-137 as an indicator of soil redistribution. Native, noneroded soils across the study area were sampled to determine a baseline value for cesium-137 (2877 Bq m−2), which was used to predict the erosion of cultivated soils since the early 1960s. Soil redistribution estimates were calculated for idealized positions (upper, middle, lower) on medium-textured cultivated hillslopes, and for the total erosional portion of the hillslopes. Mean hillslope soil erosion rates were 23 ± 8 t ha−1 yr−1 for slopes with 0–3% gradient, 27 ± 9 t ha−1 yr−1 for 3–10% slopes, and 48 ± 16 t ha−1 yr−1 for 10–24% slopes, representing a soil removal of 3.8 cm, 4.4 cm, and 7.8 cm, respectively, since 1960. These soil losses represented between 27 and 67% of the topsoil and between 8 and 35% of the solum currently present within the eroding upslope areas. A significant positive correlation existed between the thickness of soil horizons and solums, and the rate of soil erosion on the upper and middle slope positions. The greatest erosion rates were determined for the upper slope positions, probably because of a dominance of wind and tillage erosion within the area. Soil erosion rates within slope classes decreased with increasing slope length, particularly on 10–24% slopes. Erosion by overland flow was considered to be of minor importance, especially on level landscapes (0–3% gradient) where erosion averaged 23 ± 8 t ha−1 yr−1. Erosion rates ranging between 23 and 48 t ha−1 y−1 occurred over approximately 2/3 of the cultivated study area. High rates of soil erosion over such a large portion of the landscape are alarming, considering that the accepted tolerable soil loss is 11.2–4.5 t ha−1 yr−1. Key words: Soil erosion, cesium-137, water erosion, wind erosion, hillslope

Muscular dystrophy in Saskatchewan Hutterites

A slowly progressive form of muscular dystrophy was studied in a Dariusleut Hutterite kindred from a colony in west-central Saskatchewan. The disorder combines some characteristics of the dominantly inherited facio-scapulo-humeral and the recessively inherited limb-girdle types of muscular dystrophy. Intellect, vision, hearing, and sensations were normally preserved. Nerve conduction was also intact. The disorder reported herein resembles a type of muscular dystrophy we previously described in the Manitoba Schmiedeleut Hutterites [Shokeir and Kobrinsky, 1976]. This condition, which affects both sexes, appears to be genetic in origin and recessively inherited.

THE AGE OF SOME HOLOCENE SOILS ON THE EAR LAKE TERRACES IN SASKATCHEWAN

Soil profiles on the lake bottom and on four successive postglacial lacustrine terraces situated on the edge of Ear Lake in west-central Saskatchewan were studied to contribute to the knowledge of processes associated with environments of soil formation since deglaciation. Detailed morphological studies and radiocarbon dates of selected horizons indicated incipient and well-developed paleosols have formed in response to progressive formation of the terraces. The ages of the paleosols revealed a possible relationship between postglacial climatic fluctuation and the formation of these terraces. Buried soils on the lower terraces meet the criteria for Solonetzic soils while surface soils of the upper terraces have Solonetzic characteristics. The study showed the presence of soils which have characteristics reflecting more than one interval of horizon differentiation and led to the suggestion that it may be erroneous to relate their properties solely to prevailing environmental conditions. Key words: 14C dates, terrace formation, soil age, Holocene soils, paleosol, Solonetzic soil