Document generated on 09/27/2021 7:59 a.m. Géographie physique et Quaternaire A Paleoenvironmental Reconstruction of Elkwater Lake, Alberta Reconstitution paléo-environnementale de l’Elkwater Lake, en Alberta Reconstitución paleoambiental del Elkwater Lake en Alberta, Canadá Dion J. Wiseman, Garry L. Running and Andrea Freeman Drylands: Holocene Climatic, Geomorphic and Cultural Change on Article abstract the Canadian Prairies Cores retrieved from two slump blocks at the west end of Elkwater Lake, Volume 56, Number 2-3, 2002 Alberta were used to determine which of two mass wasting events was responsible for impounding the lake and to establish a maximum age of lake URI: https://id.erudit.org/iderudit/009111ar formation. A high resolution Digital Elevation Model of the study area was used DOI: https://doi.org/10.7202/009111ar to estimate the volume of material involved in each mass wasting event, recreate pre-slump topographic conditions, determine the probable extent and elevation of the lake at different periods in time, and evaluate the viability of See table of contents alternative outlets. Results suggest that the lake formed no more than 9440 BP as a result of impoundment by the eastern slump block. The lake rose to its highest mid-Holocene elevation prior to 7245 BP, establishing an outlet through Publisher(s) Feleski Creek 3.5 km northeast of the present shoreline. Lake levels then dropped during the comparatively dry Altithermal, concurrent with a period of Les Presses de l'Université de Montréal rapid sediment influx and the development of the alluvial fan on which the Stampede site is located. As water levels rose during the late Holocene, and ISSN with the former outlet cut off by progradation of the alluvial fan, Elkwater 0705-7199 (print) Lake established its present outlet though Ross Creek. 1492-143X (digital) Explore this journal Cite this article Wiseman, D. J., Running, G. L. & Freeman, A. (2002). A Paleoenvironmental Reconstruction of Elkwater Lake, Alberta. Géographie physique et Quaternaire, 56(2-3), 279–290. https://doi.org/10.7202/009111ar Tous droits réservés © Les Presses de l'Université de Montréal, 2002 This document is protected by copyright law. Use of the services of Érudit (including reproduction) is subject to its terms and conditions, which can be viewed online. https://apropos.erudit.org/en/users/policy-on-use/ This article is disseminated and preserved by Érudit. Érudit is a non-profit inter-university consortium of the Université de Montréal, Université Laval, and the Université du Québec à Montréal. Its mission is to promote and disseminate research. https://www.erudit.org/en/ GPQ_56-2-3.qxd 13/05/04 9:58 AM Page 279 Géographie physique et Quaternaire, 2002, vol. 56, nos 2-3, p. 279-290, 8 fig. A PALEOENVIRONMENTAL RECONSTRUCTION OF ELKWATER LAKE, ALBERTA Dion J. WISEMAN, Garry L. RUNNING IV and Andrea FREEMAN, respectively: Department of Geography, Brandon University, Brandon, Manitoba R7A 6A9; Department of Geography, University of Wisconsin-Eau Claire, Eau Claire, Wisconsin 54720-4004, U.S.A.; Department of Archaeology, University of Calgary, 2500 University Drive N.W., Calgary, Alberta T2N 1N4. ABSTRACT Cores retrieved from two slump RÉSUMÉ Reconstitution paléo-environne- RESUMEN Reconstitución paleoambiental blocks at the west end of Elkwater Lake, mentale de l’Elkwater Lake, en Alberta. Les del Elkwater Lake en Alberta, Canadá. El Alberta were used to determine which of two carottages effectués dans les zones des deux examen de bloques de roca obtenidos en las mass wasting events was responsible for glissements de terrain survenus à l’extrémité zonas de dos deslizamientos de terreno ocur- impounding the lake and to establish a max- ouest de l’Elkwater Lake ont servi à détermi- ridos en el extremo oeste del Elkwater Lake imum age of lake formation. A high resolution ner lequel des deux était responsable de l’en- en Alberta fue empleado para determinar Digital Elevation Model of the study area was diguement des eaux afin d’évaluer l’âge de cual de los dos eventos fue el responsable used to estimate the volume of material la formation du lac. Une modélisation numé- de la retención del agua y también para esta- involved in each mass wasting event, recre- rique à haute résolution des altitudes dans la blecer una edad máxima para la formación ate pre-slump topographic conditions, deter- région à l’étude a permis de déterminer le del lago. Una modelización numérica de alta mine the probable extent and elevation of the volume de matériel déplacé au cours de cha- resolución de la elevación del área de estudio lake at different periods in time, and evaluate cun des glissements, de recréer la topogra- fue empleada para calcular el volumen del the viability of alternative outlets. Results sug- phie préalable des lieux, de déterminer l’éten- material involucrado en cada deslizamiento gest that the lake formed no more than due et le niveau probables du lac à de terreno, reconstituir las condiciones topo- 9440 BP as a result of impoundment by the différentes périodes et d’évaluer l’existence gráficas anteriores, determinar la dimensión eastern slump block. The lake rose to its high- éventuelle d’autres exutoires. Les résultats y la elevación probables del lago durante dife- est mid-Holocene elevation prior to 7245 BP, indiquent que le lac s’est formé avant rentes periodos en el tiempo e igualmente, establishing an outlet through Feleski Creek 9440 BP par suite de l’endiguement créé par evaluar la viabilidad de canales alternativos. 3.5 km northeast of the present shoreline. le glissement situé le plus à l’est. Le lac aurait Los resultados obtenidos sugieren que el Lake levels then dropped during the compar- alors atteint son plus haut niveau avant lago se formó hace unos 9400 años como atively dry Altithermal, concurrent with a peri- 7245 BP à l’Holocène moyen, créant un exu- resultado de la contención de agua debido a od of rapid sediment influx and the develop- toire au droit du Feleski Creek, à 3,5 km au un deslizamiento de terreno en la zona este. ment of the alluvial fan on which the nord-est du rivage actuel. Le niveau du lac El lago alcanzó su elevación máxima en el Stampede site is located. As water levels rose s’est peu à peu abaissé au cours de Holoceno medio hace unos 7245 años, esta- during the late Holocene, and with the former l’Altithermal, une période relativement sèche bleciendo una salida a través de Feleski outlet cut off by progradation of the alluvial au cours de laquelle il y eut apport rapide de Creek a unos 3.5 km al noreste de la ribera fan, Elkwater Lake established its present sédiments, puis formation du delta alluvial actual. Más tarde durante un periodo de outlet though Ross Creek. aujourd’hui occupé par le site Stampede. calentamiento seco el nivel lacustre fue dis- Avec l’élévation du niveau lacustre à minuyendo coincidiendo con una afluencia l’Holocène supérieur et l’alluvionnement de rápida de sedimentos y con la formación de l’ancien exutoire, le Ross Creek est devenu le un cono aluvial en la zona que ocupa actual- nouvel exutoire de l’Elkwater Lake. mente el sitio Stampede. Durante el Holoceno superior, a medida que el nivel de agua iba aumentando, el cono aluvial blo- queó por progradación el canal inicial de sali- da y el Elkwater Lake estableció el actual canal de evacuación a través de Ross Creek. Manuscrit reçu le 10 novembre 2002 ; manuscrit révisé accepté le 3 septembre 2003 (publié en mai 2004) E-mail address: [email protected] GPQ_56-2-3.qxd 13/05/04 9:58 AM Page 280 280 D. J. WISEMAN, G. L. RUNNING IV and A. FREEMAN INTRODUCTION may exist in similar nearshore environments elsewhere in the study area. Furthermore, variations in the rate of deposition The Cypress Hills of southeastern Alberta and southwest- and textural composition of sediments deposited at the site are ern Saskatchewan are an area of unique physiographic and hypothesized to be a function of one or more of the following ecological diversity within the Canadian prairie ecozone. The factors: 1) adjustment of the fluvial geomorphic system to resulting abundance and diversity of resources has attracted changing climatic conditions; 2) change in the position of the numerous aboriginal groups to this region throughout much site on the fan as it formed; and 3) changing loci of deposition of the Holocene. The location of archeological sites within the on the fan controlled by variations in the distance to the shore- Cypress Hills is ultimately dependent on factors affecting site line of Elkwater Lake. These hypotheses can only be tested by selection and, subsequently, to processes of site formation establishing when the lake formed and how the level and extent and preservation, each of which are inherently linked to geo- of the lake has varied throughout the Holocene. morphic processes and climatic conditions. Current paleoenvironmental research in the Cypress Hills is focused on the area around Elkwater Lake (Fig. 1). The OBJECTIVES Stampede archeological site (DjOn-26) is located approxi- The objectives of this research are to: 1) evaluate the via- mately 750 m from the eastern shore of Elkwater Lake on the bility of the slump-dammed lake hypothesis as a possible proximal end of an alluvial fan and adjacent to a deeply incised explanation for the formation of Elkwater Lake and establish channel descending from the northern flank of the Cypress the age of lake formation; 2) evaluate the viability of alterna- Hills (Fig. 2). The distal end of the fan extends northwest tive outlets from Elkwater Lake northward through the Green across the Elkwater Channel.