by Charles O’Dale – the 2017 RASC GA Holleford crater exploration group shot. We are on the top of the west rim looking north-east into the crater. The crater can be seen in the background. Today it is 30 metres deep, but it is filled with ~200 metres of Ordovician sedimentary rock. So the virtual crater floor is ~230 metres below us in this image.
THE HOLLEFORD CRATER – A meteorite travelling 55,000 kilometres per hour (15.3 km/s) smashed into the earth here eons ago, blasting a hole 244 metres deep and 2.5 kilometres wide. Aerial photogrphs revealed the crater in 1955, and since then scientists have pieced together much of its geological history. Analysis of drill samples suggest that the meteorite struck in the late Precambrian or early Cambrian period (between 450 and 650 million years ago). At first the depression filled with water, becoming a circular lake. Later, Palaeozoic seas swept in sediments, filling the crater to its present depth of about 30 metres. The explosive impact of the meteorite (estimated to have been only 90 metres in diameter) is still evident in the hundreds of feet of shattered rock that drilling has detected beneath the original crater floor. [Photo taken on a prior visit.]Holleford got its name from the first postmaster; John Redmond in 1894. It was named after the village of Hollyfort, Ireland where the family had lived prior to immigrating to this area of Canada. [Photo taken on a prior visit.]
by David Lauzon – The exploration of the Holleford crater would not have been the success it was without the cooperation of property owners on the site who allowed us access to their properties. In appreciation the RASC 2017 GA gave these property owners a token of our appreciation. Here Irene is accepting our plaque from yours truly, THANK YOU.
This schematic of the Holleford Crater illustrates the geological shape difference of the west and south east crater rims (documented in images below).
Bus Ride to the Crater
by: Charles O’Dale – the bus ride to the crater.by Irene Johnston – our transportation from Ottawa to the crater.
by Charles O’Dale – on the crater floor looking west. Note the “gradual” slope of the far west rim. The group pictures were taken on the west rim top, illustrated here just above my right shoulder in the image. [Photo taken on a prior visit.]by Gillian Sullivan – a history of the crater presentation on the top of the west rim.by Irene Johnston – the group listening to my description of the crater.by Irene Johnston – our group “Canada Day” crater picture.by Mike Weckworth – descending the west crater rim to the crater floor. Note the “smooth” edge of the crater wall.by Mike Weckworth – on the crater floor looking up the smooth west crater wall. RASC crater exploration, how could it get better than this?
Crater Floor
by Julie Lacerte – the centre of the crater floor taken from the west rim. The “true” crater floor is ~200 metres below the water.by Gillian Sullivan – the RASC walking down the west rim to the crater floor, exploration at its best!by Gillian Sullivan – on the crater floor looking west.by Julie Lacerte – the north rim of the crater is illustrated here from the crater floor looking north-east.by Gillian Sullivan – the point of impact creating the Holleford crater is the clump of trees on the far side of the pond, centre of the image.by Gillian Sullivan – the centre of the crater floor is illustrated in the background. There is a ~200 metre Ordovician sedimentary “plug” in the crater, meaning that the virtual crater floor is ~200 metres below this image.
by Charles O’Dale – photo opportunity at the crater plaque.by David Lauzon – here our intrepid explorers are having lunch on the floor of the Holleford crater. How could life get any better than this?
by Mike Weckworth – on the top of the south-east rim looking north. Note the “steep scarps” of the descending rim.by Charles O’Dale – on the floor or the crater looking south toward the rising “steep scarps” of the south-east rim. [Photo taken on a prior visit.]
South Rim
by Gillian Sullivan – an example of the “travails” required to explore the optional tour of the south rim of the crater.by Gillian Sullivan – an RASC Ottawa Centre geologist explaining the features of the south crater rim.by Gillian Sullivan- an “in situ” Ordovician sedimentary rock feature on the south rim of the Holleford crater that is under “investigation”.by Brenda Shaw – an “in situ” fossil within Ordovician sedimentary rock on the south rim of the Holleford crater.by Brenda Shaw – “in situ” fossils within Ordovician sedimentary rock on the south rim of the Holleford crater.
by Charles O’Dale – in situ Ordovician sedimentary rock over the south rim. [Photo taken on a prior visit.]by Charles O’Dale – in situ Ordovician sedimentary rock over the south rim. [Photo taken on a prior visit.]by Charles O’Dale – in situ Ordovician sedimentary rock over the south rim. [Photo taken on a prior visit.]by Charles O’Dale – in situ Ordovician sedimentary rock over the south rim. [Photo taken on a prior visit.]
North Rim
by Charles O’Dale – north of the crater looking south at the crater north rim (from the outside). [Photo taken on a prior visit.]
