GeoEngineering Centre Field Trip 2013

Geology of the Kingston Area 1.1 Billion Years of Earth History

South China Seychelles India

Kalahari

Baltica Laurentia

East Antarctica

P

Siberia

A v alo nian

Rio Plata Amazonia

Congo

T i m 30°S ani an

Cado mi a n

M

vic ian

West Africa

60°S

The Supercontinent Rodinia 750 Million Years Ago...

Siberia 250 million years ago

Pangaea Baltica

30°N

North China Laurentia

Palaeotethys

South China Equator

a

ld or

ring the Ordo

iod er

W

Madagascar

du ap

30°N

North China

Australia

West Afric

Miller Museum of Geology, Miller Hall, Queen’s University

Amazonia

ot Ne

ys eth

Gondwana 30°S

Congo

Rio

India

Pl

a ta Kalahari

East Antarctica

Subduction zones

Australia 60°S

Seafloor spreading axis

Field Trip Background Info: Minerals and Rocks The 8 most abundant elements in the Earth’s crust by weight % are:

Rock-forming Minerals and their Properties Although there are thousands of different kinds of minerals, many rocks are only made up of a few common rock-forming minerals. Quartz, feldspar, and mica are common silicate minerals that are found in the igneous, sedimentary, and metamorphic rocks that we will see on the field trip in the afternoon. Calcite is a common carbonate mineral that we will see in several rocks as well. Mica:

Oxygen (O) Silicon (Si) Aluminum (Al) Iron (Fe) Calcium (Ca) Sodium (Na) Potassium (K) Magnesium (Mg)

Microcline Feldspar:

46.6% 27.7% 8.1% 5.0% 3.6% 2.8% 2.6% 2.1%

Most of the common rock-forming minerals of the crust are silicates (based on silicon and oxygen compounds).

Quartz:

The Mohs Hardness Scale of Minerals

Calcite:

1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

Hematite: Amphibole:

Classification of Rocks

Talc Gypsum Calcite Fluorite Apatite Orthoclase Quartz Topaz Corundum Diamond

(Hardness of glass plate ~5.5)

The Rock Cycle

Rocks are made up of different kinds of minerals. The types of minerals, and the way that the rock formed, can be used to determine the environment in which the rock formed.

Igneous and recrystalli zat lting ion Me

Igneous Rocks: Rocks formed from cooling molten liquids either intruded into the Earth’s crust or extruded on the surface of the Earth.

Magma/Lava ring athe we

eating

Chemical and/or Mechanical Sediments

Bu

rh d/o an iral

Metamorphic

Changes due to Heat and Pressure

dl an

ithi

ficat

ion

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n

The Earth is the ultimate recycler, and the rocks are converted from one type to another by natural geological processes over long time periods. Although nothing much seems to happen to the rocks in our lifetimes, if we could watch them over millions of years we would see tremendous changes in the rocks.

or chemi cal d e po sit io

Sedimentary Rocks: Rocks formed from cementing of mechanically weathered sediments, or from chemically precipitated sediments. Metamorphic Rocks: Rocks formed under tremendous heat and/or pressure.

(Hardness of fingernail: ~2.5)

Sedimentary

Field Trip Preparation: Geological History of Kingston The Grenville Mountains of Kingston: 1.3 Billion Years Ago. 1.8 - 1.3 billion years ago

Laurentia

The oldest rocks in the Kingston area are the metamorphic and igneous rocks of the Grenville Province of the Canadian Shield. They started out as sediments in an ocean over 1.3 billion years ago, and they were metamorphosed during the formation of a supercontinent called Rodinia. The eroded roots of the mountain range that formed in this area due to continental collisions at that time underlie the entire Kingston region.

Shallow Sea

(Proto-North America)

(Covering present-day Kingston area)

Er

os

ion Ocean

Sandstone, conglome rate mudstone,

Limestone

Eroding mountains near present-day Sudbury, Ontario, deposit sediments in a shallow sea near present-day Kingston. Limestone forms in the ocean offshore. 1.3 billion - 950 million years ago

South China

Grenville Orogeny Seychelles India

Metamorphic gneiss, schist, quartzite, and marble

Madagascar Igneous Plutons

Kalahari

Collisions with other ancient continents produced the Grenville Mountains, folding and metamorphosing the pre-existing sediments. Igneous rocks intrude forming plutons, dykes and sills.

East Antarctica

Laurentia

Siberia Rio Plata Amazonia

Congo

500 million years ago (Proto-North America)

Baltica Laurentia

Grenville Province Igneous Dykes

A v alo nian

Igneous Dykes

30°N

North China

Australia

West Africa

Cado mi a n

Laurentia

(Proto-North America)

T i m 30°S ani an

60°S

Igneous Plutons Metamorphic gneiss, schist, quartzite, and marble

The Supercontinent Rodinia around 750 million years ago.

By 500 million years ago, the Grenville Mountains were Approximate eroded to their roots.Major Plate Boundaries

Water World: Kingston in the Ordovician During the Cambrian and Ordovician Period, ocean levels were high on the Earth. Periodically during these times, North America was covered by water forming a distinctive sequence of rocks. The geography of the Earth was quite different during the Ordovician, as shown by the paleogeographic reconstructions of Dr Ron Blakey of Northern Arizona University.

Ice Age: Kingston 18 000 years ago The Earth’s climate began to cool dramatically around 1.6 million years ago. At least 4 times in the last one million years, the Kingston area has been completely covered by glacial ice. The last major ice sheet, the Wisconsin advance, covered this area until only about 10 000 years ago.

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Field Trip Preparation: Plate Tectonics Outline of the Major Tectonic Plates of the Earth Eurasian Plate

Eurasian Plate North American Plate Atlantic Pacific Plate

Mid-Ocean Ridge

Cocos Plate

Nazca Plate

Indian-Australian Plate

African Plate

South American Plate Antarctic Plate

Simplified Summary of Plate Tectonic Activity Mid-Ocean Ridge (Divergent Plate Margin) Island Arc Volcano

Continental Rift Zone (Newly-Forming Plate Boundary)

Subduction Zone

“Hot Spot” Volcano

(Convergent Plate Margin)

Trench

Trench

Continental Crust

Oc

ea

At subduction zones, the crust melts as it sinks back into the Earth again.

“Hot Spot”

nic

Cr

us

t

Rising magma adds new ocean crust at ridges

The movement of the plates is related to heat flow inside of the Earth. At mid-ocean ridges, underwater volcanoes add new ocean crust. At trenches, the ocean crust sinks down into the mantle again. “Hot spots” may be the cause of isolated volcanic island chains in the middle of the ocean (like the Hawaiian Islands).

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3 4

5 6

Legend PALEOZOIC ORDOVICIAN Period Sedimentary Rocks Black River & Trenton Groups Limestone.

13

Beekmantown Group Dolomite and sandstone.†

12

LOWER ORDOVICIAN OR CAMBRIAN Sedimentary Potsdam or Nepean Formation Sandstone.

11

UNCONFORMITY

PRECAMBRIAN PLUTONIC ROCKS (Igneous Rocks) 10

9

8

7

Diabase or porphyritic andesite dikes. Granitic gneiss, migmatite, granitized gneiss, hybrid granite gneiss, granite pegmatite. Granite and syenite. Grey granite, granite gneiss, granodiorite, tonalite. Diorite, gabbro, anorthosite, metagabbro, amphibolite. INTRUSIVE CONTACT

METASEDIMENTARY ROCKS

2

(Metamorphic Rocks formed from Sediments) 5

Quartzite, quartzo-feldspathic rocks.

4

Paragneiss, pelitic and psammo-pelitic schists and gneisses.

3

Marble, lime silicate rocks, skarn.

2

Para-amphibolite, biotite-amphibole schists and gneisses.

1

Geology of Kingston Field Trip Route September 2013 Version

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Stop #1

Barriefield Hill Roadcut. Sea Level Rise. Barriefield Hill is a gentle limestone anticline - an arch made of dipping sedimentary layers which have the youngest layers at the top of the crest and the oldest layers in the core of the arch. An upside down arch with the oldest layers on the bottom is called a syncline. One of the principles of stratigraphy (the study of sedimentary rock layers) says that sedimentary beds are originally deposited in flat, horizontal layers. So how did these layers become curved? Two possibilities exist: 1/ the flat layers were subjected to a force that folded or bent them; or 2/ the layers were deposited over a “bump” in the older basement rock and subsequent compaction over the basement high has accentuated the draping effect. There is evidence for both possibilities in this outcrop. In the south-side ditch halfway up the hill near the core of the anticline, there is an exposed “knob” of billion year old quartzite and gneiss. This resistant rock could be the basement high that the limestone layers draped over as mud was deposited from the seawater 470 million years ago. Since nothing is simple in geology however, there is evidence further up the hill (in the form of pressure-solution produced stylolites) that shows that there could have been pressure directed in an east-west sense that may have also slightly folded the sedimentary layers into the present anticlinal form.

Stylolites

Pressure Direction

Stylolites are surfaces in the rock where it has dissolved due to high directed pressure. When viewed from the side, the dissolution surface line resembles blocky “turret” shapes in the rock.

1 cm

Gentle Anticline

Quartzite/Gneiss Core at the base of the anticline.

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Stop #2

A mole-hill out of a mountain... Abbey Dawn Roadcut. The oldest rocks in the Kingston area (the “basement rocks”) are approximately 1.1 billion year old metamorphic rocks of the Canadian Shield. They formed when our part of North America (Laurentia) collided with part of South America (Amazonia). The collision produced a Himalaya-scale mountain range called the Grenville Mountains running through this area around a billion years ago. Pre-existing sedimentary rocks were changed (metamorphosed) due to the heat and pressure: sedimentary limestone became metamorphic marble, sandstone became quartzite, and impure mixtures of mud and sand became gneiss. As tectonic forces changed, the mountain-building pressures eased and weathering took over. By about 500 million years ago, the mountain range was completely eroded away leaving a barren rocky surface covered with sand, gravel and boulders. Land plants had not yet appeared on the Earth, and the land would have been bleak and barren. Harder rock ridges and knobs made up predominantly of quartzite would have been more resistant to erosion, and so some topographic relief would have been present in the area. Today, these resistant rocks are responsible for the area’s world famous 1000 Islands Region. The outcrop at the Abbey Dawn Road illustrates beautifully the response of different rock types to erosion, and shows the sequence of events in the region between 1 billion and 500 million years ago. At the north end of the outcrop, the rock is a very resistant quartzite, which stands higher than the south end which is predominantly softer gneiss that more easily eroded away. At the very south end of the outcrop is a prominent angled layer of boulders, overlain by flat-lying layers of limestone from about 470 million years ago. The fact that the limestone beds are still horizontal indicates that it hasn’t been disturbed since being deposited as layers of mud on an ocean floor around 470 million years ago. This implies that the whole outcrop shows the original orientation of the rocks when sea levels rose. The quartzite to the north was a “hill” left over from the erosion of the Grenville Mountains. Boulders rolled down the hill to the south, creating a talus slope of angular boulders against the south slope of the hill. Finally, as sea levels rose, layers of lime mud were deposited against the boulder layer, eventually becoming limestone. Since the quartzite and gneiss is around 1 billion years old, and the limestone is about 470 million years old, the 1-2 metre layer of boulders represents an erosional time gap (an unconformity) of at least 500 million years!

Undisturbed flat-lying limestone

500 million years of erosion!

Talus-slope boulder layer (conglomerate) Unconformity surface (a “non-conformity”)

Gneiss (south end) next to quartizite “hill” (north end)

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Stop #3

Can you handle the pressure... Hwy 15 and Sunbury Road Roadcut.

During the mountain building episode, pre-existing limestone was metamorphosed to marble. Just as rocks respond differently to weathering (as seen at the Abbey Dawn roadcut) rocks also respond differently to the heat and pressure of metamorphism. In this outcrop, the marble behaved like wax, easily bending and flowing under the pressure. Pieces of brittle gneiss behaved differently, first folding and then breaking into pieces that are now seen “floating” in the surrounding marble. Within the marble, grey-metallic grains of graphite can be found, which formed during the metamorphism from organic carbon that was buried in the original limestone.

Fragments of brittle gneiss surrounded by softer marble

Folded gneiss

Stop #4

Rivers flowing across a barren land... Sunbury Road. The world of 500 million years ago was a much different place. Permanent land life had not yet appeared on the Earth (neither plants nor animals) and the continents were barren and wind-swept. Sands from the weathering of the Grenville Mountains would have been blown by winds, and washed by streams meandering across the landscape. Here, the sandstone is thinly bedded and cemented partially with the mineral hematite (red iron oxide) indicating that it was probably deposited on land in a river system. Pebble layers possibly indicate floods that winnowed away the finer sand, leaving only the heavier sediments. Other sandstones in the Kingston area were originally deposited in huge dunes, or on tidal-flat beaches near the slowly rising oceans from 470 million years ago.

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Stop #5

Dykes and Plutons... Sunbury Road. In addition to metamorphism, the mountain building episode was accompanied by volcanism as well. Cracks opened up by the pressures of continental collision were filled with hot magma from below. At this outcrop, black basaltic magma filled cracks in the white quartzite forming numerous diabase dykes cutting through the rock. At the west end of the outcrop, a larger intrusive white granite can be found. Even larger intrusions (plutons) of pink granitic rock can be seen throughout the area, forming features such as Foley Mountain in Westport, Ontario.

Black diabase dyke in white quartzite

Stop #6

Crosscutting Relationships Inverary. Number the rocks and the events from oldest (1) to youngest (7) on this schematic diagram of the outcrop. Sketch a normal fault and a reverse fault.

Limestone

Disconformity (Sea Level Rise) Rideau Grit (Arkose Sandstone) Nonconformity (Erosion) Precambrian Quartzite/Gneiss

F

ke Dy au lt M ov e

ke

Dy

me nt

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