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Nine bedrock and two till samples were analyzed to determine whether their chemical and physical properties could be used to distinguish between bedrock units and to differentiate local bedrock from overlying tills. The bedrock samples came from The North Cliff subsite of the Wellsch Valley Site, and the till samples from Jaw Face subsite. Eight of the nine bedrock samples show great similarity. However, their geochemical differences from the overlying Quaternary tills establish that the tills contain much material entrained, during one or more early Quaternary glaciations, from older bedrock outcrops to the north and northeast. The glaciers that laid down the tills appear to have reworked and concentrated elements compatible with a dry climate, probably formed by weathering during long interglacial, and perhaps preglacial, intervals when the surface was undergoing slow degradation.

The basal part of Jaw Face section at the Wellsch Valley site, some 50 km north-northwest of Swift Current, Saskatchewan, contains mammalian fossils that are considered to be late Blancan to early Irvingtonian in age. It has been sampled for paleomagnetic studies through a thickness of 11 m. The section above 8.8 m has normal polarity; that below has reversed polarity. A tephra, which has yielded a minimum fission-track age of 0.69 ± 0.11 Ma, lies within the reversely magnetized part, near the top of the fossiliferous zone and just below the reversal at the 8.8 m level. Therefore, the change from normal to reversed polarity at the 8.8 m level is probably the Brunhes–Matuyama reversal at 0.73 Ma. Earlier studies have indicated that the Jaramillo (0.9–0.97 Ma) and Olduvai (1.67–1.87 Ma) Normal Polarity subzones occur within the lower predominantly reversed part of the Jaw Face section. In this more detailed study, we find no evidence of these normal subzones. We suggest that earlier results could have been artifacts of the procedures used. Several stratigraphic interpretations are possible. Our preferred interpretation is that the Jaw Face section extends from the upper part of the Matuyama Zone into the lower Brunhes Zone, that is, the mammalian faunas are entirely Irvingtonian in age. Alternatively, the section could contain a substantial hiatus, so the lower part would be early Matuyama in age and its faunas late Blancan – early Irvingtonisn, and the upper part could span the latest Matuyama and lower Brunhes zones. Other possibilities are discussed in the text.

Twelve till samples from the North Cliff section at the Wellsch Valley site, Saskatchewan, were analyzed by neutron activation to determine if trends in traced element composition would prove useful in differentiating stratigraphic units. After analyzing trace-element distributions (including rare-earth elements), no discrete stratigraphic units could be recognized from the samples studied. The eight tills in the North Cliff Section appear to be homogeneous, even though each successive glaciation apparently originated from a different source area on the Canadian Shield. The compositional data tend to enhance the impression that each successive glacier reworked sediments of similar chemical composition into younger and younger drift sheets, separated in some cases by fluvial and aeolian deposits.

This paper presents the results of a combined stratigraphical, paleomagnetic, and vertebrate paleontological study of the Maser-Frisch Site near Irvine, Alberta. At that site, about 3 m of mainly pond and stream deposits overlies Cretaceous bedrock and underlies Quaternary till and loess. All of the deposits have normal magnetic polarity. Further, the lower pond and stream deposits have yielded an interesting collection of mammal bones. Taxa identified include rabbit or hare, ground squirrel, prairie dog, bog lemming, canids, cats, badger, elephant, horses, camel, and shrub-ox. The identified taxa tentatively imply a late Irvingtonian Land Mammal Age for the fauna. This, along with their preglacial setting and normal polarity, indicates that the pond and stream deposits were laid down near the beginning of the Brunhes Polarity Chron (about 0.7 Ma) and so provide a maximum limit for the first glaciation of the region. Together, the fauna and deposits offer an interesting glimpse at conditions prevailing on the High Plains of the region at that time, which apparently resembled the dry, treeless grassland found there at present.

Teeth collected from Pleistocene surficial sediments in southeastern Alberta and western Saskatchewan have been dated by electron spin resonance (ESR). The dates generally agree with the previously determined temporal sequence of the deposits, largely based on studies of fossil vertebrates and supplemented by some absolute ages, but the absolute ages of the oldest deposits appear to be much younger than previously estimated. Absolute ages (ESR) have been compared with faunal ages (using nomenclature of Stalker and Churcher): the age of Aftonian – early Kansan deposits at the Maser–Frisch site is 450 ± 30 ka; Kansan deposits in the Medicine Hat region range from 410 to 250 ka; Sangamon deposits at Mitchell Bluff are 67 ± 12 ka; middle Wisconsinan deposits at Empress, Alberta, are 34 ± 4 ka; postglacial beds near Medicine Hat give ages of 11 ± 2 ka (in agreement with 14C ages). At Wellsch Valley, however, ESR dates (280 ± 35 ka) are much younger than the age of about 1.5 Ma obtained from fauna, fission track, and paleomagnetics. This discrepancy may be due to late introduction of U into the teeth.

The margin of a former Laurentide ice sheet is traced through southern and central Alberta, from the Saskatchewan border southeast of Medicine Hat to beyond Rocky Mountain House, southwest of Edmonton. This margin, which marks the limit of a significant glacier advance or readvance, is thought to represent the maximum extent of Laurentide ice on the Canadian prairies during Classical Wisconsin time. In the south this margin follows a well-developed hummocky moraine; in the north it is indicated mainly by a discordance in trend of ice-flow markings, a disruption of drainage, and a change in maturity of topography on either side.

Eight separate till sheets are displayed at the North Cliff, which is part of the Wellsch Valley site in Saskatchewan. Those tills are differentiated by using physical characteristics, particle size, clay and primary mineralogy, and sediment chemistry. Grain size tends to fine downward in the section, and a significant increase in the mean [Formula: see text] centre of gravity indicates that some weathering occurred after deposition of the tills. Within the clay mineral suites, smectite tends to dominate in all eight tills, indicating that the paleoclimate was generally as dry as the present-day climate. Only till number 4 (counting from the bottom) contains halloysite; this halloysite may have been entrained from a preweathered surface by the glacier, or it may have formed in situ following deposition. Among the primary minerals, quartz dominates throughout the section, whereas plagioclases are least abundant in tills 4 and 5, possibly as a result of postdepositional weathering. Element composition shows only minor changes for Cu, Pb, Zn, Co, and Ni, whereas Mo increases upward in the section, Cr remains uniform in tills 1, 2, 3, 7, and 8 but increases slightly in tills 4–6, and Mn increases downward, possibly as a response to fluctuating amounts of groundwater. Till 4 forms the best stratigraphic marker in the sequence because of its high Mn content and the presence of halloysite, but till 5 also contains distinctive features in its element composition.The clay composition of the surface soil, which has formed in the top till since the departure of the last glacier, resembles that found in the underlying tills, whereas quartz and plagioclase are present in lesser amounts. These properties reflect both weathering in a semiarid climate and the presence of preweathered material from earlier paleosols.

The prominent terraces north of Bow River at Cochrane, Alberta, divide readily into an upper and a lower set. The three terraces of the upper set represent deltas built into lakes ponded in front of Laurentide ice. They were constructed between 19 000 and 15 000 years ago, when Classical Wisconsin glaciation was near its maximum. Due to the inhospitable conditions then prevailing, these upper terraces contain few or no fossils. During a warm interstade that followed, the glaciers shrank and Bow River deepened and enlarged its valley until ice readvance, about 12 000 years ago, stopped this phase of erosion. Before the glaciers in the Bow and its tributary valleys again retreated, more than 10 000 years ago, Bow River had deposited vast quantities of fill in its valley. Since then, the river has carved the five lower terraces from that fill and from the underlying bedrock.The valley fill is here named "Bighill Creek Formation". It is a valuable source of gravel and sand, and a prolific supplier of vertebrate fossils. Most of the latter come from a sand unit, here called "Clarke Pit Member", which extends throughout much of the formation. Radiocarbon dates indicate that the member is about 11 000 years old.

'Saskatchewan gravels and sands' is the name used for numerous, widely scattered deposits of gravel and sand found on the Canadian Prairies. These deposits represent the final phase of deposition by preglacial rivers before the first Pleistocene ice-sheet disrupted regional drainage. In the past, Saskatchewan gravels and sands have been identified chiefly by their absence of stones from the Canadian Shield and position below the drift in buried valleys or on low ground. These remain the basic criteria. Sole dependence on them, however, has resulted in extraneous deposits being called Saskatchewan. Such misidentifications cannot be eliminated entirely, but their number can be greatly decreased by use of additional checks. These include intensive study of each deposit and its topographic position, and establishing that there was both an adequate source for the gravel and sand contained in it and competent means of transporting that material from source to present site. In addition, the valley containing the deposit must have formed an integral part of the preglacial drainage system, its cross-section and longitudinal profile must have resembled those of a typical preglacial valley, and there must not have been any competing valley that could have carried the local, preglacial drainage more efficiently.

Elements from the left hind foot of a small horse, probably Equus conversidens Owen, are reported from a few miles southeast of Medicine Hat, Alberta. The bones were found below a buried soil contained within an eastward-striking glacial spillway. A date of about 8000 y B.P. is suggested for the specimens on stratigraphic considerations. If this date is correct, these bones probably represent the youngest indigenous fossil horse known in North America.

230Th and 231Pa dates were obtained on 10 bone samples from Quaternary deposits near Medicine Hat, Alberta. The youngest date so obtained (9500 ± 1500 years) agrees reasonably well with a radiocarbon date (11 200 ± 200 years) from the same site. In addition, where samples were collected from more than one bed at the same bluff the results are in the correct chronological order. A Sangamon bed containing chipped stones, thought to be artifacts, gave a date of 72 000 ± 6000 years, which is acceptable, though at the younger end of the previously estimated age range of between 200 000 and 70 000 years for the bed.In general, however, the results reveal large discrepancies with the estimated ages of the beds that yielded the bones. Although several causes for the discrepancies are possible, in two or three instances the uranium-series dates themselves appear to be incorrect, and the other dates must be treated with caution.

Human bones, found by the writer's geological field party in 1961, came from a cliff (Woodpecker Island Bluff) on the east side of Oldman River about 3 mi. north of Taber, Alberta. This paper discusses stratigraphy of the bluff and age of the bones, which have been described by Langston and Oschinsky (1963). The bones cannot be dated directly; however, they were found about 60 ft. below prairie level, in a sand unit lying beneath a till sheet. As the till was deposited by a Classical Wisconsin ice sheet that spread over the area more than 22,000 years ago, the bones are at least that old. Correlation with other bluffs along Oldman River indicates they are more than 32,000 years, and probably more than 37,000 years, old.

Radiocarbon dates from the Castle River Valley of southwestern Alberta indicate that the last major glacier advance down that valley reached its maximum extent 6200 radiocarbon years ago. This advance is considered to be late Pinedale in age. The Pinedale then ended with onset of the “Climatic Optimum” or “Altithermal,” which lasted in that region from about 6000 to 4500 years B.P. The dates were obtained on bison bones found in outwash near the base of a 250-ft-high cliff. This cliff, here called Mountain Mill Bluff, lies on the south side of Castle River, 7 miles east of the Rocky Mountains and 6 miles due west of the town of Pincher Creek. The lower part of the outwash extends downvalley from a terminal moraine (Mountain Mill Moraine) of the former Castle Valley Glacier. The bison wandered into a meltwater stream draining from that glacier about 6200 years ago, drowned, and were buried by outwash accumulating below the moraine. As moraine and out-wash were laid down contemporaneously, dates on the bison bones indicate the time of construction of the moraine.