Document generated on 09/26/2021 3:28 a.m. Géographie physique et Quaternaire Stratigraphic and Structural Framework of Upper Middle Ordovician Rocks in the Head Lake-Burleigh Falls Area of South-Central Ontario Cadre stratigraphique et structural des roches de l’Ordovicien moyen supérieur dans la région de Head Lake-Burleigh Falls, au centre-sud de l’Ontario Stratigraphischer und struktureller Rahmen der Felsen aus dem oberen mittleren Ordovizium in der Gegend von Head Lake-Burleigh Falls im südlichen Zentrum von Ontario Bruce V. Sanford La néotectonique de la région des Grands Lacs Article abstract Neotectonics of the Great Lakes area Field investigations in the Head Lake-Burleigh Falls area of south-central Volume 47, Number 3, 1993 Ontario, that focused mainly on the Covey Hill(?), Shadow Lake, Gull River and Coboconk formations along the Paleozoic escarpment, provided clear evidence URI: https://id.erudit.org/iderudit/032956ar of faulting. Observed and inferred structural deformation, coupled with faciès DOI: https://doi.org/10.7202/032956ar changes within the Shadow Lake and lower Gull River, point to a succession of basement movements during the Phanerozoic. These range from Hadrynian-Early Cambrian, through Middle Ordovician to post-late Middle See table of contents Ordovician times. Some of the earlier movements (Hadrynian-Early Cambrian to late Middle Ordovician) appear to be coincident with, and probably related to, plate tectonic events and the associated Taconian orogeny that were in Publisher(s) progress along the southeastern margins of the North American continent. Post-Middle Ordovician block faulting, on the other hand, may have been Les Presses de l'Université de Montréal triggered by any number of epeirogenic events related to late stage Taconian, Acadian or Alleghanian orogenies in Late Ordovician to Carboniferous times, ISSN or possibly to rifting associated with continental break-up and initiation of 0705-7199 (print) seafloor spreading processes in the early Mesozoic. Manuscrit révisé accepté le 1492-143X (digital) 5 août 1993 Explore this journal Cite this article Sanford, B. V. (1993). Stratigraphic and Structural Framework of Upper Middle Ordovician Rocks in the Head Lake-Burleigh Falls Area of South-Central Ontario. Géographie physique et Quaternaire, 47(3), 253–268. https://doi.org/10.7202/032956ar Tous droits réservés © Les Presses de l'Université de Montréal, 1993 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/ Géographie physique et Quaternaire, 1993, vol. 47, n° 3, p. 253-268, 15 fig. STRATIGRAPHIC AND STRUCTURAL FRAMEWORK OF UPPER MIDDLE ORDOVICIAN ROCKS IN THE HEAD LAKE- BURLEIGH FALLS AREA OF SOUTH- CENTRAL ONTARIO Bruce V. SANFORD, Independent Exploration Geologist,17 Meadowglade Gardens, Nepean, Ontario K2G 5J4. ABSTRACT Field investigations in the RÉSUMÉ Cadre stratigraphique et structu­ ZUSAM M EN FASSU NG Stratigraphischer Head Lake-Burleigh Falls area of south- ral des roches de l'Ordovicien moyen supé­ und struktureller Rahmen der Felsen aus central Ontario, that focused mainly on the rieur dans la région de Head Lake-Burleigh dem oberen mittleren Ordovizium in der Covey Hill(?), Shadow Lake, Gull River and Falls, au centre-sud de l'Ontario. Des levés Gegend von Head Lake-Burleigh Falls im Coboconk formations along the Paleozoic de terrain faits dans la région de Head Lake- sùdlichen Zentrum von Ontario. FeId- escarpment, provided clear evidence of Burleigh Falls, portant surtout sur les forma­ forschungen im Head Lake-Burleigh FaIIs- faulting. Observed and inferred structural tions de Covey HiII (?), Shadow Lake, Gull Gebiet, sùdliches Zentrum von Ontario, die deformation, coupled with faciès changes River et Coboconk ont fait ressortir la pré­ sich haupt-sàchlich auf die Bildungen von within the Shadow Lake and lower Gull sence de failles. Les déformations tecto­ Covey Hill(?), Shadow Lake, Gull River und River, point to a succession of basement niques observées et supposés, ainsi que les Coboconk entlang des palàozoischen movements during the Phanerozoic. These changements de faciès dans le Shadow Steilabfalls konzentrierten, ergaben ein kla- Lake et le cours inférieur de la GuII River, range from Hadrynian-Early Cambrian, res BiId der Verweiiung. Die beobachteten montrent qu'il y a eu une succession de mou­ through Middle Ordovician to post-late und vermuteten strukturellen Verformungen Middle Ordovician times. Some of the earlier vements du socle pendant le weisen zusammen mit Fazies-Ànderungen movements (Hadrynian-Early Cambrian to Phanérozoïque. Ces mouvements se sont im Shadow Lake und dem unteren Lauf des late Middle Ordovician) appear to be coinci­ produits de l'Hadryanien-Cambrien inférieur GuII River auf eine Aufeinander-folge von dent with, and probably related to, plate tec­ à l'Ordovicien moyen, puis jusqu'après l'Or­ Untergrundbewegungen wàhrend des tonic events and the associated Taconian dovicien moyen supérieur. Certains des pre­ Phanerozoikums. Dièse reichen vom frùh- orogeny that were in progress along the miers mouvements (Hadryanien- Cambrien hadrynischen Kambrium durch das mittlere southeastern margins of the North American inférieur à l'Ordovicien moyen) semblent Ordovizium bis zu Zeiten nach dem spàten continent. Post-Middle Ordovician block coïncider avec la tectonique des plaques, et mittleren Ordovizium. Einige der frùheren faulting, on the other hand, may have been y être reliés, et avec l'orogenèse du triggered by any number of epeirogenic Taconique qui s'est manifestée sur les Bewegungen (frùh-hadrynisches Kambrium events related to late stage Taconian, marges sud-ouest du continent nord- bis spates mittleres Ordovizium) scheinen Acadian or Alleghanian orogenies in Late américain. La formation de failles dans les mit der Tektonik der Platten sowie der tako- Ordovician to Carboniferous times, or possi­ blocs après l'Ordovicien moyen, d'autre part, nischen Orogenèse, welche entlang der bly to rifting associated with continental a pu être provoquée par un ou plusieurs sudôstlichen Rander des nordamerikanis- break-up and initiation of seafloor spreading événements épirogénétiques liés aux oroge­ chen Kontinents stattgefunden haben, zei- processes in the early Mesozoic. nèses du dernier étage du Taconique, de tlich zusammenzufallen und verbunden zu l'Acadien et de l'Alléghanien de l'Ordovicien sein. Die Bildung von Brùchen in den supérieur au Carbonifère pendant la forma­ Blôcken nach dem mittleren Ordovizium tion des fossés d'effondrement lié à la sépa­ kônnte andererseits durch ein oder mehrere ration des continents et le début de l'expan­ epirogenetische Ereignisse ausgelôst wor- sion océanique au Mésozoïque inférieur. den sein, verbunden mit den Orogenesen der letzten takonischen, akadischen und alleghanischen Stufe vom spàten Ordovizium bis zum Karbon, oder wohl auch verbunden mit Spaltung auf Grund des Auseinanderbrechens der Kontinente und dem Beginn der Ausbreitung des Meeresbodens im frùen Mesozoikum. Manuscrit révisé accepté le 5 août 1993 254 B.V. SANFORD INTRODUCTION these is the southwest-trending Central Metasedimentary Belt Boundary Zone (CMBBZ) that was tectonically active Upper Middle Ordovician carbonate rocks have a wide dis­ during the Grenvillian orogeny (Hanmer, 1988). This struc­ tribution in the Great Lakes region of Canada and the United tural element is exposed on the Canadian Shield and contin­ States. They are present in the subsurface in the Michigan ues to the southwest beneath the Paleozoic cover rocks. and Appalachian basins. From there they rise to the surface Other linear features (that may represent possible structural along the periphery of both tectonic elements to form an out­ boundaries) are magnetic anomalies that, in general, parallel crop belt extending from the Adirondack region of New York the NE-SW structural grain of the Central Metasedimentary State, through south-central Ontario, to the states of Michigan Belt (Geological Survey of Canada, 1989). Finally there are and Wisconsin (Douglas, 1969; Sanford and Baer, 1981). linear topographical features, including the major drainage systems, superimposed on the Paleozoic terrain. These In south-central Ontario, upper Middle Ordovician carbon­ appear to have orientations similar to those of the surface lin­ ate rocks onlap two major positive tectonic elements (Fig. 1), eaments in neighbouring segments of the Canadian Shield the Algonquin and Frontenac arches, both of which are and are, thus, conceived as possible major fracture systems. known to have undergone vertical tectonic movements through successive periods of Precambrian and Paleozoic time (Sanford et al., 1985). To obtain a general understand­ Prior to field investigations, the bedrock geology of the ing, as to the timing and magnitude of these movements, a Head Lake-Burleigh Falls area was compiled onto modern field survey was carried out in 1992 to investigate one small 1:50,000 scale topographical maps (Energy, Mines and segment of Paleozoic terrain where it onlaps Precambrian Resources, 1979, 1980) from geological maps prepared by basement rocks of the Frontenac