A History and Preview of A History and Preview of SupercontinentsSupercontinents Through TimeThrough Time

OutlineOutline1.1. A Brief History of A Brief History of SupercontinentsSupercontinents

2.2. ““VaalbaraVaalbara”, “Ur” and “”, “Ur” and “ProtopangeaProtopangea” The First ” The First SupercontinentSupercontinent??

3.3. “Columbia”“Columbia”-- Son of “Ur”Son of “Ur”

4.4. RodiniaRodinia-- The Mad Momma of The Mad Momma of SupercontinentsSupercontinents

5.5. PannotiaPannotia-- Fastest Fastest supercontinentsupercontinent in the south.in the south.

6.6. PangeaPangea-- The forerunner of The forerunner of AmasiaAmasia

7.7. AmasiaAmasia-- The future The future supercontinentsupercontinent..

8.8. Why do we care how continents are positioned according to the spWhy do we care how continents are positioned according to the spin axis?in axis?

-- True Polar Wander and Inertial Interchange EventsTrue Polar Wander and Inertial Interchange Events

-- Dynamics of Plate Motion and ReorganizationDynamics of Plate Motion and Reorganization

-- Impacts on Climate and Life?Impacts on Climate and Life?

-- Evolution of the Magnetic Field.Evolution of the Magnetic Field.

The Oldest The Oldest SupercontinentsSupercontinents-- A Brief Historical A Brief Historical Perspective (PPT)Perspective (PPT)

A series of papers in the early 1970’s by Dewey, Burke and ColleA series of papers in the early 1970’s by Dewey, Burke and Colleagues noted agues noted the existence of previous zones of continental rifting and collithe existence of previous zones of continental rifting and collision sion foreshadowing the possibility of previous foreshadowing the possibility of previous supercontinentalsupercontinental assemblages.assemblages.

JDA Piper (1970’s) used the extant JDA Piper (1970’s) used the extant paleomagneticpaleomagnetic database to propose the database to propose the existence of a longexistence of a long--lived Precambrian lived Precambrian supercontinentsupercontinent which he later dubbed which he later dubbed Proto and Proto and PaleoPaleo--PangeaPangea..

The main problem with the Paleo(and Proto) Pangea models is that the paleomagnetic data no longer support this long-lived reconstruction and there are numerous geological problems with the model.

SouthAmerica

Africa

ArabiaIran

IndiaAntarctica

NorthAmerica

RussiaScandanavia

~600 Ma

In 1984, Gerard Bond and In 1984, Gerard Bond and others proposed the existence others proposed the existence of a of a NeoproterozoicNeoproterozoicsupercontinentsupercontinent based upon the based upon the ubiquitous presence of ubiquitous presence of passive passive margin sequencesmargin sequences around the around the globe. They suggested that the globe. They suggested that the supercontinentsupercontinent broke apart at broke apart at the Precambrian/Cambrian the Precambrian/Cambrian boundary.boundary.

Passive marginsPassive margins form at form at locations where rifting of locations where rifting of continents beginscontinents begins

Subsequent Subsequent supercontinentalsupercontinental models have been forwarded models have been forwarded throughout the 1990’s up to the present and include throughout the 1990’s up to the present and include VaalbaraVaalbara ((ZegersZegers and colleaguesand colleagues) “) “UrUr” (” (RogersRogers), ), ProtoPangeaProtoPangea ((PiperPiper), “), “ColumbiaColumbia” (” (Rogers and Santosh, Rogers and Santosh, Zhao and colleaguesZhao and colleagues), “), “RodiniaRodinia” (” (McMenaminMcMenamin and and McMenaminMcMenamin; ; MooresMoores, , DalzielDalziel, Hoffman, Hoffman) and “) and “PannotiaPannotia” ” ((PowellPowell).).

That earlier That earlier supercontinentssupercontinents should exist is not surprising should exist is not surprising given the mobile nature of the Earth’s given the mobile nature of the Earth’s upper thermal upper thermal boundary layerboundary layer ((e.g. lithospheree.g. lithosphere))

VaalbaraVaalbara SupercontinentSupercontinent: Pre 2.7 : Pre 2.7 GaGa assembly of the assembly of the KaapKaapvaalvaal

CratonCraton (S. Africa) and the (S. Africa) and the PilPilbarabaraCratonCraton (W. Australia)(W. Australia)

A

combined

structural,

geochronological,

and

palaeo

A

combined

structural,

geochronological,

and

palaeo

CheneyCheney (1996) and later (1996) and later ZegersZegers et alet al. . (1998) noted that the sequence (1998) noted that the sequence stratigraphicstratigraphic and and chronostratigraphicchronostratigraphic data data showed remarkable similarities between showed remarkable similarities between these two these two cratonscratons..

PaleomagneticPaleomagnetic tests initially supported the tests initially supported the configuration (configuration (ZegersZegers et al., 1998et al., 1998); ); however later work however later work WingateWingate (1998) argued (1998) argued against against VaalbaraVaalbara at ~2.8 Ga.at ~2.8 Ga.

““Ur”Ur”

Rogers (1996) also noted that the Rogers (1996) also noted that the KaapvaalKaapvaal cratoncraton, the , the PilbaraPilbara cratoncraton, , the Western the Western DharwarDharwar cratoncraton (India) the (India) the SinghbhumSinghbhum cratoncraton (India) and (India) and portions of coastal east Antarctica were all “stabilized” (e.g. portions of coastal east Antarctica were all “stabilized” (e.g. accumulated accumulated platform sediments that were left platform sediments that were left undeformedundeformed) by 3.0 Ga. He linked ) by 3.0 Ga. He linked these together in a single landmass which he named “Ur”. Subseqthese together in a single landmass which he named “Ur”. Subsequent uent growth of Ur occurred to form the East Gondwana landmass. growth of Ur occurred to form the East Gondwana landmass.

The Growth of “Ur” from 3.0 to 1.5 Ga according to Rogers (1996).

““Ur” in Younger Ur” in Younger SupercontinentsSupercontinents--Piper’s Piper’s ProtoPangeaProtoPangea

PiperPiper (1982, 1987, 2000, 2003) (1982, 1987, 2000, 2003) has argued repeatedly that the has argued repeatedly that the paleomagneticpaleomagnetic data support a data support a longlong--lived Precambrian lived Precambrian supercontinentsupercontinent. .

A careful examination of A careful examination of paleomagneticpaleomagnetic poles with good poles with good age control shows gross age control shows gross inconsistencies with this model. inconsistencies with this model. This model needs to be This model needs to be considerably revised or considerably revised or completely discardedcompletely discarded ((Van der Van der Voo and Meert, 1991; Meert and Voo and Meert, 1991; Meert and Torsvik, 2004Torsvik, 2004).).

ArcticaArctica

AtlanticaAtlantica

UrUr

The “Columbia” The “Columbia” SupercontinentSupercontinent ((Rogers and Rogers and Santosh, 2002; Zhao et al., 2004Santosh, 2002; Zhao et al., 2004))

Rogers and Santosh (2002) concluded that a supercontinent called “Columbia” was assembled during the interval from ~1.9-1.8 Ga. Key observations supporting their hypothesis were cited as:

- The existence of numerous 1.9-1.8 Ga orogenic belts

- A series of ~1.5 Ga rift basins associated with the breakup of the supercontinent.

Zhao et al. (2002, 2003, 2004) Zhao et al. (2002, 2003, 2004) Updates to ColumbiaUpdates to Columbia

Zhao et al. have detailed the evidence for Columbia in a series of papers, Specific evidence cited by Zhao et al. for their version of Columbia includes:

•The formation of Nuna (Gower et al., 1990) composed of the North American protocraton and possibly Baltica (northern Europe) during the interval from 2.1-18. Ga.

• Presence of 2.1-1.8 Ga orogenic belts (these include the Trans-Hudson; Penokean; Taltson-Thelon; Wopmay; New Quebec; Torngat; Foxe; Makkovik-Ketilidian; Ungava; Nugssutoqidian; Kola-Karelian; Svecofennian; Volhyn; Palchema; Akitkan; Transantarctic; Capricorn; Limpopo; Transamazonia; Eburnean; Trans North China; Central Indian Tectonic Zone; Central Aldan; Halls Creek).

•Continental Rift Basins and ‘anorogenic’ magmatism beginning ~1.6 Ga.

Distribution by Distribution by continent of 2.1continent of 2.1--1.8 1.8 GaGa orogenicorogenic belts as belts as described by Zhao et described by Zhao et al. (2004)al. (2004)

The ‘Columbia” Supercontinent of Zhao et al., 2004.

The Demise of the The Demise of the ColumbiaColumbia SupercontinentSupercontinent at 1.5 at 1.5 GaGa (Zhao (Zhao et al., 2004)et al., 2004)

The The RodiniaRodinia SupercontinentSupercontinent

First proposed by McMenamin and McMenamin (1990) as the birthplace for the Cambrian explostion. Later Moores (1991) proposed a link between the SW US and East Antarctica and Australia (SWEAT) during the Mesoproterozoic and called this the SWEAT fit. Shortly thereafter (Dalziel, 1991) proposed a supercontinent based partly on the SWEAT hypothesis. This was followed by a proposal from Hoffman (1991) and a decade long series of papers examining the evidence for Rodinia.

Data supporting a supercontinent during the Meso-Neoproterozoic:

1.1-0.9 Ga Orogenic Belts

Neoproterozoic rift basins and passive margin sequences around the globe.

Geologic, geochronologic and paleomagnetic evidence are supportive but often highly divergent on the exact makeup of theSC.

What did Rodinia Look Like?What did Rodinia Look Like?

MozambiqueOcean

BrasilianoOcean

800-700 Ma Rift

600-550 Ma Rift

1: Meert and Torsvik

‘Traditional’ Rodinia(?)Traditional’ Rodinia(?)

--How were continents How were continents distributed along the distributed along the western margin of western margin of LaurentiaLaurentia??

--Where does Siberia Where does Siberia fit?fit?

--What continents What continents occupied the SW and E occupied the SW and E LaurentianLaurentian margins?margins?

Issues with the Northern and Western Issues with the Northern and Western Margins of Margins of LaurentiaLaurentia

•• SWEAT, AUSWUS, SWEAT, AUSWUS, AUSMEX, SIBCOR or ??AUSMEX, SIBCOR or ??

•• When did rifting occur? When did rifting occur? Subsidence data says Subsidence data says ~550 Ma, most models ~550 Ma, most models posit an earlier 700posit an earlier 700--800 800 Ma rifting.Ma rifting.

Laurentia

BalticaAUS(SWEAT)

AUS(AUSWUS)

ANT(SWEAT)

ANT(AUSWUS)

Amazonia

Congo

RP

K3K2

K1

K4

SFCSFC

Congo

Siberia?

From: Meert and Torsvik (in press)

RKS

RKS

DB

DB

Meert and Torsvik, 2003Meert and Torsvik, 2003

SiberiaSiberia

•• 3 Distinct fits3 Distinct fits– Arctic Margin with a variety of orientations

(e.g. Pelechaty, 1996; Rainbird et al., 1998; Frost et al., 1998; Condie and Rosen, 1994)

– Cordilleran Margin (e.g. Sears and Price, 2000)

– Not part of younger Rodinia (e.g. Hartz and Torsvik, 2002; Meert and Torsvik, 2003)

Laurentia

Congo

K3K2

K1

Weil et al. (1998)

Dalziel et al. (2000)Powell et al. (2001)

K4

SFC

SFC

Congo

Figure 3a: Meert and Torsvik (in press)D

B

DB

DB

DB

DB

Meert & Torsvik (in press)

There have been any number There have been any number of fits proposed for the of fits proposed for the Kalahari & Congo Kalahari & Congo CratonCraton. . These myriad fits are These myriad fits are primarily based on:primarily based on:

A.A. ‘Need’ for a southern ‘Need’ for a southern continent to collide with continent to collide with SS--SW US during SW US during GrenvillianGrenvillian times (times (DalzielDalzielet al., 2000).et al., 2000).

B.B. Comparison of Comparison of APWP’sAPWP’sfrom from LaurentiaLaurentia--Congo and Congo and Kalahari (Weil et al., Kalahari (Weil et al., 1998; Powell et al., 2001; 1998; Powell et al., 2001; Meert and Torsvik, 2003)Meert and Torsvik, 2003)

KalahariKalahari--CongoCongo

Laurentia

BalticaAUS(SWEAT)

ANT(SWEAT)

Amazonia

Congo

RP

K3

K1

K4

SFCSFC

Congo

Figure 3a: Meert and Torsvik

RKS

RKS

DB

DB

AmazoniaAmazonia: : New paleomagnetic data from Tohver et al. (2002) New paleomagnetic data from Tohver et al. (2002) hint that hint that AmazoniaAmazonia might be the ‘southern’ continent.might be the ‘southern’ continent.

MozambiqueOcean

BrasilianoOcean

800-700 Ma Rift

600-550 Ma Rift

1: Meert and Torsvik

““SPUEG” Fit (750 Ma; SPUEG” Fit (750 Ma; HartzHartz & & Torsvik, 2002). Torsvik, 2002).

Note: Fit works for 1100Note: Fit works for 1100--1000 Ma poles, 1000 Ma poles, but not for 930but not for 930--850 Ma suggesting some 850 Ma suggesting some readjustments between readjustments between BalticaBaltica--LaurentiaLaurentia

Figure 3b: Meert and Torsvik

~1225 Ma

RKS

Laurentia

Baltica

Amazonia

BalticaBaltica

This fit is made by using This fit is made by using paleomagnetic data from paleomagnetic data from BalticaBaltica(Pesonen et al., in press) at 1225 (Pesonen et al., in press) at 1225

Ma and fitting the 1.55Ma and fitting the 1.55--1.60 1.60 rapikivirapikivi suites from suites from AmazoniaAmazoniaand and BalticaBaltica ((GeraldesGeraldes et al., et al.,

2001)2001)

Issues W/Issues W/RodiniaRodinia1.1. Mesoproterozoic to Early Neoproterozoic Fits between continentalMesoproterozoic to Early Neoproterozoic Fits between continental blocks blocks

are critically dependent on choice of paleomagnetic data (includare critically dependent on choice of paleomagnetic data (including polarity) ing polarity) and choice of geologic links.and choice of geologic links.

2.2. New paleomagnetic data challenge ‘traditional’ Rodinia modelsNew paleomagnetic data challenge ‘traditional’ Rodinia models——especially especially with respect to the Australiawith respect to the Australia--Antarctic blocks and Antarctic blocks and AmazoniaAmazonia..

3.3. The new The new paleomagneticallypaleomagnetically based models leave significant lengths of based models leave significant lengths of Neoproterozoic Neoproterozoic LaurentianLaurentian passive margin sequences with no conjugate.passive margin sequences with no conjugate.

4.4. Geologic links can be used to argue for nearly any fit (or no fiGeologic links can be used to argue for nearly any fit (or no fit) between the t) between the various various cratonscratons thought to compose Rodinia.thought to compose Rodinia.

5.5. Nearly 20 years since the Bond et al. proposal and a dozen yearsNearly 20 years since the Bond et al. proposal and a dozen years since the since the McMenaminMcMenamin and and McMenaminMcMenamin proposal, we still have no definitive proposal, we still have no definitive configuration for Rodinia.configuration for Rodinia.

PannotiaPannotia (Powell, 1995)(Powell, 1995)

The existence of Pannotia is predicated on the notion that Gondwana assembly was completed prior to the opening of the Iapetus Ocean along the eastern margin of Laurentia.

Timing is crucial- Gondwana assembly appears to have culminated somewhere between 570-530 Ma (Meert, 2003). Rifting in northeastern Laurentia and Baltica began around 615 Ma (Kamo et al., 1989; Svenningsen, 2001).

Paleomagnetic data are somewhat equivocal, but at best this supercontinent would have existed for no more than 15-20 Ma.

The breakup of Pannotia may have been quite rapid. This rapid transition has led to numerous hypotheses regarding the dynamics of plate driving mechanisms and/or episodes of true polar wander (Kirschvink et al., 1997; Evans, 1998; Meert, 1999; Meert and Tamrat, 2003; Evans, 2002, Meert and Lieberman, 2004).

Laurentia

Amazonia

Baltica

RioPlata Sao Fracisco

Congo

EastAntarctica

Kalahari

Sri Lanka SeychellesMadagascar

India

East Africa Orogen

Arabian-Nubian Shield

WestAfrica

AegirSea

Cadomian Arc

IapetusOcean

MawsonSea

PacificOcean

30 S 60 S

Passive Margin

Siberia

Avalonia

Mawson Sea

X

Ægir Sea

Siberia

WesternGondwana

Ava

loni

aArmorica

East

Ant

arct

ica

Baltica

Laurentia ?

Equator

30 S

60 S

SP

Iapetus

X

Gondwana

Siberia

Baltica

Laurentia

Avalonia

Equator

30 S

60 S

SP

580 Ma 550 Ma 500 Ma

The Key to solving this issue is The Key to solving this issue is to acquire high quality to acquire high quality paleomagneticpaleomagnetic data from data from LaurentiaLaurentia and and BalticaBaltica..

PangeaPangea

The most recent supercontinent reached maximum packing around 250 Ma and began to break apart shortly thereafter (225-175 Ma).

From Torsvik, 2003

The Future The Future SupercontinentSupercontinent+250 Ma+250 Ma

Does the Pacific Persist? If so, you get Does the Pacific Persist? If so, you get PangeaPangea--UltimaUltima ((ScoteseScotese, 2000, 2000))

Does the Atlantic become the next superocean? If so, you get Amasia.

SupercontinentalSupercontinental CyclicityCyclicity??

Given many caveats regarding the timing of Given many caveats regarding the timing of supercontinentalsupercontinentalassembly in the assembly in the ProterozoicProterozoic, it would appear that , it would appear that supercontinentssupercontinents will form, on average, every 500will form, on average, every 500--700 million 700 million years.years.

Why?Why?