Connecting people with nature in Ontario's Mississippi Valley

Mississippi Valley Field Naturalists Get a Reading Lesson

The following account of the Wednesday October 25, 2017 ‘geology’ event Reading the Rocks.

Wednesday was a beautiful cool, crisp October morning as the Mississippi Valley Field Naturalists and friends gathered in  Metcalfe Geoheritage Park for “Reading the Rocks,” led by Neil Carleton, a founding MVFN member. It was the perfect backdrop for the drama that was about to unfold. Four dozen heads tilted backward as Neil began our breakneck journey through geological time, by sweeping his arms skyward, pulling the Grenville Mountains from their ancient roots, to dizzying heights. Beneath these towering behemoths, we imagined the tremendous heat and pressure that would transform the rock, limestone to marble and shale to schist, 20 km beneath our feet.

photo Brenda Boyd

photo Brenda Boyd

 

Meanwhile, as the continents restlessly wandered the globe, Neil’s arms fell as the equatorial landmass that would become North America was covered in a succession of tropical oceans. His voice filled with awe as he described the diversity of marine life in the warm, shallow seas. Pointing downriver to a distant landmark, he was ready to take us further on our exploration in time, but closer to the present when a cooling climate triggered a global ice age.  Tipping the landscape on its head, the outcrop now stood 2 km atop a glacier. We could almost hear the grinding of the massive continental ice sheet in its relentless advance, scouring the landscape and smoothing the bedrock to a polished finish.  Neil’s hands and arms floated away from his body as the ice melted leaving behind the rock debris known as glacial till.

Neil then turned to the scientific record of the events he had described so eloquently. It is all there in the folded layers, bedrock striations, and colourful minerals if you take the time to read the rocks. He pointed to a large slab of micaceous schist that formed deep in the roots of the Grenville Mountains. He traced the fossils of predatory cephalopods, the uniquely preserved burrows of soft-bodied organisms, and the rippled sediments frozen in the rock of what was once the near shore bottom of an Ordovician Sea. Ruler straight lines on the face of one boulder and a conglomerate rock formed by the cementation of igneous, sedimentary and metamorphic rocks formed in very different ways, in very different places, that had been carried in and under the ice sheet, and left behind were evidence of the melting ice as it receded from the area only some 11,500 years ago.

The group then moved to tables of fossil specimens that Neil had set up for closer examination. A microscope allowed a look at the fine details of the corals, brachiopods, and trilobites that inhabited the prehistoric seas of our area.  A scavenger hunt of geological words further engaged us in our exploration of rock and fossils. Neil wrapped up the morning by answering questions and distributing “loot bags” containing local rock samples with labels, along with shells from the Champlain Sea.

Metcalfe Geoheritage Park is located  at the base of  Bay Hill (i.e. at the rivers edge at 250 Almonte Street in Almonte. For directions see http://mvfn.ca/events/reading-the-rocks/).  Try your hand at reading the rocks. There are pamphlets at the park to help you, or bring along your smartphone and access in-depth information, through the QR codes located at the base of each sample. Learn what the rocks have to tell us about the fascinating geological history of Almonte and the surrounding area.

By Gretta Bradley

Almonte's Metcalfe Geoheritage Park photo P. Donaldson (1280x591)

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Did ‘geo’ hear about the recent geoheritage tour?

WHEN?  Saturday, June 13, 2015

 WHO?   Twenty-five Mississippi Valley Field Naturalists (MVFN) members,  led by Dr. Allan Donaldson, Professor Emeritus, Department of Earth Sciences, Carleton University. 

photo Neil Carleton

MVFN members arrived at Metcalfe Geoheritage Park in Almonte by car, on foot, and on their bicycles.

WHAT ?   This was a full day geoheritage tour to examine and reflect on the geoheritage of our area.

 

Ordovician Sea Bottom (1024x682)

 In this postcard image (an artist’s interpretation of our local environment during the lower Ordovician period) one can see that about 470 million years ago a tropical ocean teeming with marine life covered our region.

Geoheritage Tour 9 June 13 2015 (732x1024)

The fossil remains of ancient Ordovician sea life can be seen in the area’s limestone bedrock.

Geoheritage Tour 3 June 13 2015 (1024x768)

WHERE? Metcalfe Geoheritage Park & two additional sites: The group gathered at this very picturesque location in Almonte: Canada’s first municipal geoheritage park; this park is new and nearing completion.

Geoheritage Tour 5 June 13 2015 (1024x768)

Geoheritage Tour 10 June 13 2015 (1024x767)

The local metamorphic, sedimentary, and igneous rocks on display at Metcalfe Geoheritage Park in Almonte tell a story of towering mountains, ocean depths, colliding continents, and a landscape locked in ice over the past 1.2 billion years.

The group continued the tour after lunch, traveling via car-pool to two additional sites of interest.

Geoheritage Tour 6 June 13 2015 (1024x768)

The ancient geology of the Canadian Shield in the Carp area was examined at the 2nd tour site.

Geoheritage Tour 7 June 13 2015 (1024x768)

At the third site, the glacially sculpted contours and fossils of recently exposed limestone bedrock invited close inspection.

NOTE: Photos and [most] text by MVFN founding and current member Neil Carleton

 

 

 

 

 

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Geoheritage Tour with Allan Donaldson

This full day geology tour for MVFN members and friends will be led by Dr. Allan Donaldson. The tour will start at the outdoor display of rock specimens at Almonte’s Metcalfe Geoheritage Park. We will spend the morning there discussing the rocks on display, as well as a suite of additional hand specimens of rocks and fossils representative of local geology.

After lunch (from approx. 11:45 am – 1 pm), the tour will continue with an afternoon drive and visits to outcrops of both Precambrian bedrock and fossil-bearing Paleozoic strata.

Date: Saturday, June 13, 2015

Time: 9:30 am

Location: Meet at the parking lot, Metcalfe Geoheritage Park, Almonte St. (South of Mill St.) in Almonte. In the afternoon we will be going to two other sites, with a return to Almonte at approximately 4:30 pm. Please arrange to car pool to minimize the number of vehicles for travel in the afternoon.

Bring: lunch, hat, sunglasses, sunscreen, bug repellant, and hiking boots (the afternoon sites are on open but uneven rocky areas free of brush and boggy areas, so wear hiking boots rather than rubber boots). We will be observing rather than collecting, so also consider bringing a hand lens and camera.

You must pre-register for this event:  please contact Gretta Bradley at  or 613-256-4202.  Please remember to give your name and the event/s you are registering for.

NOTE: Our geoheritage tour leader,  Dr.Allan Donaldson (B.Sc. Geol. Eng., Queen’s; Ph.D. Sedimentology, Johns Hopkins), spent 10 years as a Research Scientist with the Geological Survey of Canada investigating Precambrian strata in Canada’s  northern Territories. He then joined Carleton University’s Department of Geology, where he taught for 30 years and during this time he and his graduate students continued research work in the north. Soon after retiring in 1996, Allan founded the Ottawa-Gatineau Geoheritage Initiative, an organization devoted to advancing public appreciation of the underpinnings of the landscape: via talks, field excursions and networking with other nature-based groups. In the past, Allan has led several other geology tours for MVFN.

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Geoheritage Tour

The Friends of Murphy’s Point Park are hosting a Geoheritage Tour on Saturday, October 25th, 2014.  For full details please see the poster below and the Friends of Murphy’s Point Park Website.

For further information about geological heritage of our area, visit the Ottawa-Gatineau Geoheritage Project website. The Ottawa-Gatineau Geoheritage Project promotes greater public knowledge and appreciation of the geology and related landscapes in and around Canada’s National Capital Region.

 

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MVFN Geotour of Lanark County

A Geotour of Lanark County

Saturday, July 17, 2010 —— 9:00 a.m. – 4:30 p.m.

 Accompany Dr. Allan Donaldson on a geoheritage tour of our region to learn about stratigraphy, fossils, and the Canadian Shield.

 Meet: at Metcalfe Park, in Almonte at 9:00 a.m. for outing introduction and to carpool. Metcalf Park is at the bottom of the lower falls on the Mississippi River near the new Hydro development site in Almonte,  From Hwy 29, turn toward Almonte at traffic lights (Almonte St.) and park is at the bottom of the hill on your left before you reach Mill St. in Almonte and before crossing over the first bridge.

 Tour itinerary:

1. Drive directly to one of the Cavanagh quarries – Stratigraphy and fossils

2. Parking area, east side of Pakenham Bridge – Fossils and stratigraphy

3. Lunch (at Pakenham or en route to next stop)

4. Smith’s Falls – Building stone and memorial cairn – recognition of rocks, primary and secondary structures, and evaluation of likely source

5. Civitan Court in front of Crystal Palace, Perth – Display of rocks from the Precambrian Shield (a potential geoheritage park, complementary to Metcalfe Geoheritage Park); nearby local building stone; possible visit to Matheson House Museum

6. Return to Metcalfe Geoheritage Park, Almonte, 4:30 p.m.

 Bring: lunch, boots with steel toes (or your most protective footwear if you don’t have such boots) and safety hat (if you have one) for the quarry, sun hat, sunscreen, hand lens, binoculars, camera, your natural history notebook, insect repellant, and lots to drink

For further information please contact Cathy Keddy at 613-257-3089

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