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60-723: The Oak Ridges Moraine Conservation Act , officially known as the Oak Ridges Moraine Conservation Act, 2001 , is a conservation plan for land situated on or near the Oak Ridges Moraine in Ontario , Canada . The legislation was enacted by the Government of Ontario in 2001. The primary purpose of the legislation is to protect the ecological and hydrological integrity of the Oak Ridges Moraine. The legislation

120-538: A North American varve chronology. Carl Caldenius visited Patagonia and Tierra del Fuego , and Erik Norin visited central Asia . By this stage, other geologists were investigating varve sequences, including Matti Sauramo who constructed a varve chronology of the last deglaciation in Finland . 1940 saw the publication of a now classic scientific paper by De Geer, the Geochronologia Suecica , in which he presented

180-489: A ban on all development on the Oak Ridges Moraine. This announcement sparked considerable opposition by the development industry which, in turn, attracted considerable media attention and public interest. A media campaign by environmental groups built on the public opposition of the developments, and the issue was transferred to the Ontario Municipal Board (OMB) in 2000. By May 2001, with the issue still unresolved,

240-567: A long-term timescale. However, by 2012, “missing” varves in the Lake Suigetsu sequence were identified in the Lake Suigetsu 2006 Project by overlapping multiple cores and improved varve counting techniques, extending the timescale to 52,800 years. Varves form in a variety of marine and lacustrine depositional environments from seasonal variation in clastic , biological, and chemical sedimentary processes. The classic varve archetype

300-611: A network of sites along the east coast of Sweden was established. The varved sediments exposed in these sites had formed in glaciolacustrine and glacimarine conditions in the Baltic basin as the last ice sheet retreated northwards. By 1914, De Geer had discovered that it was possible to compare varve sequences across long distances by matching variations in varve thickness, and distinct marker laminae. However, this discovery led De Geer and many of his co-workers into making incorrect correlations, which they called 'teleconnections', between continents,

360-511: A period of slowing meltwater runoff. Channel fill sediments comprise the base of Oak Ridges Moraine sediments , atop the unconformity. Lower deposits of the Oak Ridges Moraine sediments stratigraphic package start as coarse sands and gravels whereas upper sediments are interbedded fine sands and silts with channel fill . There may also be sequences of sediments decreasing in size from medium sands to silts and clays up to ten's of metres thick. Above these sediments lie clayey-silt to silt till of

420-475: A process criticised by other varve pioneers like Ernst Antevs . In 1924, the Geochronological Institute, a special laboratory dedicated to varve research was established. De Geer and his co-workers and students made trips to other countries and continents to investigate varved sediments. Ernst Antevs studied sites from Long Island , U.S.A. to Lake Timiskaming and Hudson Bay , Canada, and created

480-499: A relatively short period of time, perhaps no more than a few hundred years, as indicated by the annual deposition cycles in glacial lakes (known as varves ) within the moraine sediments. However, the lowest beds in the moraine may have experienced synchronous sedimentation. In the area of the Oak Ridges Moraine, glacially derived sediments, mainly of Pleistocene age, may overlie a regional unconformity and lower Newmarket till, up to 200 metres thick in some places. Extensive research in

540-456: A robust and resilient environment across the ORM landscape. These objectives include; undertaking science-based research; providing opportunities for recreation; taking action for the protection and restoration of the ORM and; providing expert advice for environmental planning and policy matters. Local concerns for preserving wildlife habitat on the moraine have increased in recent years. In April 2000,

600-463: A shortage in servicing capacity, what often appears as "new" development in Markham, Vaughan, Richmond Hill, Whitchurch-Stouffville and King Township on the moraine is in the majority of cases development which has had approval for many years. The greatest threat to the function of the moraine is land development on and below its surface, particularly in the headwaters. The estimated current population on

660-399: A source of potable water for numerous communities, both federal and provincial governments have invested resources towards research on the moraine. The Geological Survey of Canada and Ontario Geological Survey both investigate hydro stratigraphy and hydrology throughout the moraine. Palaeo-Indian hunter-gatherers were in this area between 11,000 - 9,500 BP. The oldest artifact found in what

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720-440: Is a coalition of nine Conservation Authorities with watersheds on the Oak Ridges Moraine (ORM). The Coalition formed in 2000 two years prior to the ORM conservation Plan, in response to the need for a comprehensive policy, planning and management approach geared to sustaining the health of the entire ORM. The CAMC is a partnership organization. It collaborates with numerous groups and individuals to achieve common objectives to support

780-409: Is a light / dark coloured couplet deposited in a lake basin. During summer months, light lamine composed of silica and calcium carbonate are deposited. This is the consequence of dead phytoplankton , and other micro-organisms that create their skeletons or shells out of silica or calcium carbonate, falling to the lake bottom. This process of the precipatation and deposition of dead micro-organisms out of

840-547: Is a pair of large ridges composed of four elevated wedges. It is bounded to the west by the Niagara Escarpment, a cuesta which was critical to the formation of the moraine, and to the east by the Trent River and Rice Lake. The four wedges ( Albion , Uxbridge , Pontypool and Rice Lake from west to east) formed in stages, though some synchronous formation also occurred at an early period of formation. The moraine peaks at

900-565: Is an annual layer of sediment or sedimentary rock . The word 'varve' derives from the Swedish word varv whose meanings and connotations include 'revolution', 'in layers', and 'circle'. The term first appeared as Hvarfig lera (varved clay) on the first map produced by the Geological Survey of Sweden in 1862. Initially, "varve" referred to each of the separate components comprising a single annual layer in glacial lake sediments , but at

960-584: Is now Richmond Hill, Ontario, from these people, was a stone scraper about 40 mm long, at the Mortson Site, near Leslie Street and 19th Avenue. Other artifacts were found in a settlement site on the eastern shore of Lake Wilcox. Late Archaic artifacts c. 3800 BP have also been found at the Silver Stream site, near the headwaters of the Rouge River on Leslie Street, just north of Major Mackenzie Drive, and at

1020-507: Is representative of the unequal effects of regional erosion, uplift, sedimentary deposition and continental processes (tectonics, building and destroying of continents). Rocks from the Grenville Province of Precambrian age lie below Ordovician aged limestones and shales in much of the Oak Ridges Moraine area. These come from a period of continental scale orogeny in eastern North America about 1.2 to 1.3 billion years ago. This area of

1080-481: Is silt with some clay content, as layers of 2 to 20 metres (6.6 to 65.6 ft) thick in places. Glacial sediments are subject to erosional forces and valley cutting processes, removing previously laid sediments and placing them further along the river path. At the Oak Ridges Moraine system, rocks from the Ordovician Period underlie the post-glacial sediment and are a large part of the bedrock geology, aside from

1140-401: Is the transition of deposition layers from glaciofluvial to glaciolacustrine . Sedimentary glaciofluvial areas form the core of the Oak Ridges Moraine, though restricted to subglacial cavity fills of confined subaqueous fans . Overlaying this core is a glaciolacustrine sedimentary layer that is younger and topographically lower, principally in the delta and basin areas of the moraine. In

1200-421: Is the water source for many headwaters streams flowing south into rivers that drain into Lake Ontario and north into rivers that drain into Lake Scugog and Lake Simcoe . Varied landforms on the moraine, such as woodlands , wetlands , watercourses , kettle lakes and bogs , have provided an environment suitable for significant flora and fauna communities to develop and thrive. The moraine contains one of

1260-462: The Halton Till , at thicknesses reaching 20 metres (66 ft). The Halton Till is not present over the entire expanse of the moraine, cropping out locally and interspersed. Glacial lake sediments cap the entire sequence of Oak Ridges Moraine sediment stratigraphy in the region, namely from two glacial lakes, Lake Algonquin and Lake Iroquois . The main depositional ingredient from these lakes

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1320-511: The Newmarket Till of stony, silty sand and sandy-silt diamicton ranging from 5 to 50 metres (16 to 164 ft) thick and is thought to extend southward under Lake Ontario. Cutting into the Newmarket Till is another regional unconformity, which led to coarse grained channel fill sediments. Some channel fills are 10 to 25 metres of gravels or 10-to-75-metre (33 to 246 ft) sands that decrease in grain size during later deposition following

1380-599: The Oak Ridges Moraine Land Trust was formed. The ORMLT is a non-profit organization that raises funds to protect areas on the moraine through conservation easements and outright purchases. They have protected 6 square kilometres (1,500 acres). The Nature Conservancy of Canada is also active and are raising funds to protect a 5.4 km (1,300 acres) property called Happy Valley Forest. 44°03′N 78°52′W  /  44.050°N 78.867°W  / 44.050; -78.867 Varve A varve

1440-455: The moraine is currently under dispute; environmental groups such as the Sierra Club maintain the area's delicate ecosystems are threatened by development pressures. Attractive forests and hilly relief typical of the moraine are a magnet for developers looking for building opportunities in the densely populated Greater Toronto Area . However, many planners and residents see a need to preserve

1500-476: The 1910 Geological Congress, the Swedish geologist Gerard De Geer (1858–1943) proposed a new formal definition, where varve means the whole of any annual sedimentary layer. More recently introduced terms such as 'annually laminated' are synonymous with varve. Of the many rhythmites in the geological record, varves are one of the most important and illuminating in studies of past climate change . Varves are amongst

1560-693: The Esox site, on the eastern shore of Lake Wilcox. Although preservation of the moraine was first suggested in the 1940s, it was not until 1991 that the issue achieved prominence in political discourse. Part of the reason for its entry into political discourse, was due to the formation, in 1989, of the Save the Oak Ridges Moraine (STORM) Coalition. The Government of Ontario created the Oak Ridges Moraine Technical Working Committee in June 1991, with

1620-575: The Grenville Province is mainly composed of metamorphosed gneiss and mylonite , while also including intrusions of granitic composition as well. Both the metamorphic and igneous rocks are able to better withstand erosional forces from the advancing ice sheets compared to some softer rock types. Softer metamorphic rocks of the Precambrian basement include marbles or meta turbidites , both from sedimentary origin. The ecologically diverse moraine

1680-635: The Late Ordovician to Early Silurian time. Large gaps in deposition from the Early Silurian through Mesozoic time allowed large scale erosion to occur in this geographic region, to the onset of Quaternary glaciation and subsequent sediment deposition. A 1997 report from the Geological Survey of Canada estimates the bedrock thickness to range between 50 and 500 metres (160 and 1,640 ft) thick, below approximately 200 metres (660 ft) of Pleistocene aged sediments. This broad range of thickness

1740-513: The Middle Ordovician brought in a second sequence of deposition as clastic and carbonate sediments above this new unconformity. A third depositional sequence is found in the Late Ordovician, separated from the Middle Ordovician by local erosion and clastic sediments, consists of a shale base topped with more shale interbedded with limestone and calcareous siltstones . Above this is yet another unconformity, this time due to sea regression in

1800-635: The Oak Ridges Moraine in Richmond Hill and Uxbridge . The exchange settled outstanding disputes being considered by the OMB involving moraine lands in Richmond Hill and Uxbridge. Despite all these efforts, including the government's creation of a permanently protected Greenbelt , the political struggle regarding the moraine continues. Unless approved prior to the Oak Ridges Moraine Conservation Act coming into force in 2001 or through orders of

1860-552: The Ontario Municipal Board to the contrary, development on the Oak Ridges Moraine is restricted to the Settlement Area. Smaller-scale development which improves the ecological integrity of the moraine is permitted in other areas (i.e., tree farm), but is otherwise restricted. Given that the land-subdivision process is lengthy and that Markham, Vaughan, Richmond Hill, Whitchurch-Stouffville and King Township are experiencing

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1920-514: The Rice Lake wedge . Near the Rice Lake wedge and Peterborough drumlin field are a couple of low-lying terrain plains and small hills on bedrock basement. The Oak Ridges Moraine probably formed in the Late Wisconsin glacial period. Ice melt from the Niagara Escarpment flowed into the western boundaries of the moraine, wherein conduits beneath the ice expanded to form a west-to-east passage between

1980-589: The Swedish Time Scale, a floating varve chronology for ice recession from Skåne to Indalsälven . Ragnar Lidén made the first attempts to link this time scale with the present day. Since then, there have been revisions as new sites are discovered, and old ones reassessed. At present, the Swedish varve chronology is based on thousands of sites, and covers 13,200 varve years. In 2008, although varves were considered likely to give similar information to dendrochronology , they were considered "too uncertain" for use on

2040-478: The Uxbridge wedge, generally rising from east to west, a result of the moraine's west-to-east formation. That is, the western portion of the moraine received earlier and more frequent sedimentary deposition than the eastern portion, as the ice lobes which controlled the moraine's eastern formation slowly retreated. The Rice Lake wedge is separated from the other wedges where the Oak Ridges Moraine intersects Rice Lake. As

2100-549: The absence of bioturbation . Consequently, varves commonly form under anoxic conditions. A well-known marine example of varved sediments are those found in the Santa Barbara basin, off California . Another long record of varved sediments is the palaeo-lacustrine record of the Piànico–Sèllere Basin (southern Alps). Here, the detrital layer part of each varve was used as a proxy for 771 palaeofloods which occurred over

2160-531: The aim of creating a regional planning strategy for the moraine. The plan was completed in 1994, but was subsequently dismissed in favour of local government administration of the affected lands. This led to intense development on some portions of the moraine. In early 1999, developers targeted Richmond Hill for large subdivisions on the moraine which would house over 100,000 people. On July 20, 1999, Minister of Municipal Affairs and Housing Steve Gilchrist announced, on "Rouge Park Day", that he would be implementing

2220-403: The clay into coarse grains. Since the saline waters leave coarse particles all year, it is nearly impossible to distinguish the individual layers in salt waters. Indeed, clay flocculation occurs at high ionic strength due to the collapse of the clay electrical double layer (EDL), which decreases the electrostatic repulsion between negatively charged clay particles. Although the term varve

2280-449: The connected systems. A specific concern is urbanization, which affects water quality by increasing its load of metals and organic contaminants. A study by Cook et al. (1985) found an increase in mean annual runoff , instantaneous discharge, and hydrograph peak flow as a result of urbanization: "...changes in land use coincided with changes in volumetric and time distribution aspects of hydrologic response". In 1829, John Bigsby conducted

2340-403: The first investigation of the moraine. He noted the elevation, and styled the area Oak Ridge , identifying the portion of moraine north of Toronto . The moraine's extent was not established until 1863 when William Logan conducted the Geological Survey of Canada . Taylor formally defined the landform as the Oak Ridges Moraine in 1913. He described its extent to be from King and Maple in

2400-766: The land mass of the moraine and only those development projects which had already received zoning and planning approval were allowed to be completed. During the provincial election of 2003, the Liberal Party of Ontario promised to terminate development on the moraine as part of their election campaign. The government, in its attempt to halt developments, proposed the North Pickering Land Exchange. This involved exchanging government-owned public lands in North Pickering (the Seaton lands) for privately owned lands on

2460-677: The last large contiguous forested spans in southern Ontario. Some of the wide variety of plant and animal species found in the moraine are species at risk in Canada and Ontario, including the West Virginia white butterfly , Jefferson salamander , and red-shouldered hawk . Unique ecosystems in the moraine include wetlands similar to those of boreal forests in Northern Ontario, and remnants of tallgrass prairie and oak-pine savanna that are globally threatened ecosystems. A representative portion of

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2520-472: The late stages of its development, random unstratified accumulation (known as diamicton ) occurred along the ice margins. Whereas the glacial river deposits were more substantial by volume, the diamicton deposits represent a greater portion of the moraine's exposed surface. Research suggests that sedimentation occurred in a west to east sequence along the four main sedimentary wedges: Albion , Uxbridge , Pontytool and Rice Lake . The wedges may have formed in

2580-516: The lithostratigraphic and geographical record. Cause of this stratigraphic gap may originate from a couple large scale meltwater events, the older Algonquin and younger Ontarian erosional floods from melting glaciers of the Late Wisconsinan glaciation. Basement layers are composed of Early Ordovician aged dolostone as a first sequence only to be stripped away by erosion in the Middle Ordovician. Sea transgression during continent reformation in

2640-574: The main Laurentide Ice Sheet and a mass of ice in the Lake Ontario basin. Stratified sediment was deposited rapidly on the high-relief erosional surface. Up to 150 metres (490 ft) in some areas, the deposits occurred on surfaces defined by highly eroded channels and drumlin uplands. The channel tunnels were primarily created by the erosion from glacial rivers, a typical process before moraine formation. Characteristic of this moraine

2700-474: The moraine area indicate there may be 6 different periods of sedimentation from the onset of glaciation. There are lower deposits of sand, silt and clay, which rest directly above the regional time unconformity up to 100 metres (330 ft) thick in some areas. These lower deposits are thought to be proglacial lake derived, and contain from bottom to top: York Till, Don Interglacial beds, Scarborough Formation, Sunnybrook Till and Thorncliffe Formation. Next comes

2760-537: The moraine from the negative aspects of urban sprawl . Moreover, because it is a rich resource for sand and gravel, it has become a significant source of materials for the aggregate industry of the Greater Toronto Area. Fisher and Alexander in the early 1990s described a "metropolitan" invasion of the Oak Ridges Moraine, in response to which organizations such as Save the Oak Ridges Moraine (STORM) were formed. Conservation Authorities Moraine Coalition (CAMC)

2820-468: The moraine is a local topographic high, streams originating in the lower Oak Ridges Moraine sediment packages, by groundwater movement, either flow south into Lake Ontario or north toward Lake Simcoe or Georgian Bay through large river valleys carved during melting of glaciers. To the north are drumlinized uplands, referred to as the Peterborough drumlin field, which may continue south of Rice Lake and

2880-624: The moraine land itself is roughly 200,000 but this number continues to grow at a frantic pace, with large urban developments occurring in Stouffville , Vaughan , Richmond Hill , and Aurora . This rapid development is especially apparent in Oak Ridges, where land previously set aside for conservation has, as of 2009, been opened up by the Richmond Hill Town Council for development. Another five million people live in close proximity. Use of

2940-599: The moraine may be found in the Happy Valley Forests , in York Region , north of Toronto . A number of features comprise the hydrological system of the Oak Ridges Moraine: This hydrological system is inter-twined with a regional flow systems not bound by the morphological limits of the moraine. For this reason, environmentalists and researchers promote an aggressive protection strategy extending beyond

3000-473: The moraine or nearby areas must satisfy several conditions, most prominently that each development leave a buffer zone of 30 metres (98 ft) between it and any hydrological feature; for a kettle lake, this measure is from the edge of the lake's catchment area. The Oak Ridges Moraine's hydrological system is a major constituent of the Humber Watershed , so that any factors affecting the moraine may affect

3060-400: The moraine were deposited in an esker (Brennand and Shaw, 1994); and that the moraine is not continuous, but is composed of multiple depositional environments : subglacial, ice-marginal and proglacial lacustrine (Barnett et al., 1998). Current research efforts on the moraine are quite extensive. Because of the political implications of development on the moraine, and because its aquifers are

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3120-529: The moraine, thus ensuring a contiguously protected hydrological system. Preservation of aquifers under the moraine is especially important, since they are used as a primary water source by some municipalities located on or near the moraine. These aquifers also discharge into tributaries that are the headwaters of approximately 65 creeks and rivers which eventually flow into Lake Simcoe, Lake Scugog and Lake Ontario or Georgian Bay. The Oak Ridges Moraine Conservation Act stipulates that any development which targets

3180-494: The presence of some older basement rock beneath. From the basement rocks to the overlying stratigraphic successions is an unconformity (a gap in the geologic record) where many millions of years of depositional or crystalline record are erased (mostly Silurian to Pleistocene rocks) by regional erosion processes and continent building phases. A large time gap is important in this context to correlate where and when this event occurred with respect to both local and surrounding geology of

3240-514: The provincial Conservative government announced a six-month moratorium on moraine development. A panel was formed to create a land-use plan consistent with the current "smart growth" policy. The plan was released in October 2001, and became the basis for Bill 122, the Oak Ridges Moraine Conservation Act, 2001 , which divided the moraine into four zones with increasingly stringent controls on development in each. The Act prevented development of over 92% of

3300-433: The smallest-scale events recognised in stratigraphy . An annual layer can be highly visible because the particles washed into the layer in the spring when there is greater flow strength are much coarser than those deposited later in the year. This forms a pair of layers—one coarse and one fine—for each annual cycle. Varves form only in fresh or brackish water, because the high levels of salt in normal sea water coagulate

3360-509: The water column is resticted to warm months when productivity (ecology) is high. The corresponding dark colored layers are composed of organic matter and fine sediment particles transported and deposited during spring freshets as a result of winter snowmelt. The alternation of these two distinct layers allows for high-precision dating of sediment profiles, for each couplet is equivalent to one year. In addition to seasonal variation of sedimentary processes and deposition, varve formation requires

3420-617: The west to the Trent River in the east. He also proposed that its origin was overlapping, interlobate glaciation retreat, between the Lake Ontario Lobe and the older Lake Simcoe Lobe . This has become the accepted explanation for the moraine's development, though research in the 1970s suggested the moraine may not be interlobate. Research conducted in the 1990s revealed that the moraine has multiple origins: its eastern area has subglacial depositions (Gorrell and McCrae, 1993); early parts of

3480-545: Was Gerard De Geer. While working for the Geological Survey of Sweden, De Geer noticed a close visual similarity between the laminated sediments he was mapping, and tree-rings . This prompted him to suggest the coarse-fine couplets frequently found in the sediments of glacial lakes were annual layers. The first varve chronology was constructed by De Geer in Stockholm in the late 19th century. Further work soon followed, and

3540-479: Was not introduced until the late nineteenth century, the concept of an annual rhythm of deposition is at least two centuries old. In the 1840s, Edward Hitchcock suspected laminated sediment in North America could be seasonal, and in 1884 Warren Upham postulated that light-dark laminated couplets represented a single year's deposition. Despite these earlier forays, the chief pioneer and populariser of varve research

3600-680: Was passed by the Legislative Assembly of Ontario on 13 December 2001, and received royal assent the next day. The government also released the Oak Ridges Moraine Conservation Plan regulation, which defined land use and planning policies consistent with the Act, and assigned interim directors to the new Oak Ridges Moraine Foundation . This article about Canadian law is a stub . You can help Misplaced Pages by expanding it . Oak Ridges Moraine The Oak Ridges Moraine

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