Stratigraphy and paleogeography of Gondwana · PDF fileStratigraphy and paleogeography of Gondwana GéoRessources - CREGU - CNRS UNIVERSITE DE LORRAINE Vienna 06-2015 – Karoo U...

Stratigraphy and paleogeography of

Gondwana

GéoRessources - CREGU - CNRS UNIVERSITE DE LORRAINE

54 506, Vandoeuvre les NANCY FRANCE Vienna 06-2015 – Karoo U Basins michel.cuney@univ-lorraine.fr

The Gondwana supercontinent

Gondwana supercontinent incorporated: S. America, Africa, Arabia,

Madagascar, India, Sri Lanka, Australia, New Zeland, Antarctica +

pieces of Europe

South & North China blocks were close to Australia, as indicated

by bioprovince connections with east Gondwana during the Early to

mid-Palaeozoic

Cambrian–Ordovician: deposition of a thick pile of Qz-rich

sandstones on the Gondwana over > 6000 km from the Atlantic

coast of N. Africa to Arabian Peninsula

In Europe Armorican Quartzite Formation

Its breakup started in the Early Jurassic (180 Ma)

Torvik and Cocks, 2013 3

Formation of Gondwanaland

A: Amazonia; A: E-Avalonia; AN: Arabia-Nubia; wA: W-Avalonia; B: Baltica; C: Congo; CAFB: C. Asian Fold B.;

EA: E.Antarctica; ES: E.Svalbard; G: Greenland; I: India; K: Kalahari; L: Laurentia; NA: N.Australia; NC: N.China;

R: Rio Plata; S: Sahara; SA: S. Australia; SC: S. China; Sf: Sao Francisco; Si: Siberia; T: Tarim; WA: W. Africa

High continental topography, and the lowering of sea level

W. Africa

Amazonia

Congo Sahara

E. Africa

Kalahari

India

N. Australia

S. China

W-Avalonia

Laurentia

Siberia

Baltica

Li et al.,

2013

Formation of

Gondwanaland

A: Amazonia; A: E-Avalonia; AN:

Arabia-Nubia; wA: W-Avalonia;

B: Baltica; C: Congo; EA:

E.Antarctica; I: India; K: Kalahari;

L: Laurentia; NA: N.Australia;

NC: N.China; R: Rio Plata; S:

Sahara; SA: S. Australia; SC: S.

China; Sf: Sao Francisco; T:

Tarim; WA: W. Africa

W. Africa

Amazonia

Congo

Sahara

E. Africa

Kalahari

India

N. Australia

S. China

W-Avalonia

S. Australia

Li et al.,

2013

540 Ma Tarim

E-Avalonia

Sao Francisco

Map of Gondwana showing position of the cratonic nuclei (after Gray et al., 2008).

THE KAROO FORMATION Series of basins developed on the Gondwana continent.

Stratigraphic limits:

• between Carboniferous and Jurassic (360-180 Ma), end with the regional

basalt flooding event

• theoretically ended with the initiation of the Gondwana break up during

Lower Jurassic

Paleogeographic extension of the Karoo sedimentation:

• S & E of Africa from South Africa to Somalia-Ethiopia (largest development),

• West Africa: Angola, Namibia, Democratic Republic of the Congo,

• North of Africa: Niger, …

• South America (Paraguay, Argentina, Brazil, Bolivia…)

• Asia (India, Saudi Arabia, Australia ….)

• But also Permian sediments with U in Europe (Gondwana ?)

Calculated effect of supercontinent cycle on sea level during Phanerozoic

Comparison with first-order eustasy, degree of platform flooding & number of continents

K A R O O

Permo-Triassic, Jurassic, Cretaceous fluvio-deltaic Gondwana sediments

potential for U mineralisation in:

Beaufort Group, Karroo basin of South Africa (Le Roux, 1985),

Parana basin, S. America (Barretto, 1985),

France (Comte et al., 1985),

Niger (Cazoulat, 1985),

Ngalia, Amadeus & Cooper basins, Australia

Gondwana basins, India.

Callingastaupstata Basin, Sierra Pintada, Argentina

Proliferation of land plants & their incorporation in fluvial to marginal marine,

poorly sorted sediments derived from fertile granitic & metamorphic rocks with

high U contents in interbedded tuffaceous rocks (as an additional source of U)

make Gondwana sediments a favorable host for sandslone type U deposit.

(Finch & Davis, 1985; Le Roux & Toens, 1987)

THE KAROO

Basins

In the

southern half

of Africa

The Karoo Basin

The Karoo U Province sediments

Includes parts of Adelaide Subgroup, & a smaller, crescent-shaped satellite

region in the Molteno and Elliot formations.

Thickest sandstones host the largest ore bodies & these sandstones are

up to 70 m thick in Adelaide Subgroup & up to 40 m thick in Molteno & Elliot

Formations.

Sandstone bodies = meandering river & sheet flood deposits in Adelaide

Subgroup,

= braided & meandering deposits in Molteno Formation

= meandering & sheet flood deposits in Elliot Formation

Sandstone bodies interbedded with dark green, greyish red & maroon

mudstone + subordinate siltstone, more abundant in Adelaide Subgroup &

Elliot Form. and = to sandstone in the Molteno Formation.

Damien DELVAUX 2001

Karoo basin system in the NW-

trending Ubende Belt Tanzania & E. Congo reflects an early

stage of Gondwana break-up

Karoo basins, much larger than the

remaining ones, formed initially as a

result of tectonically controlled

subsidence during the Late

Carboniferous - Permian & were filled by

fluvial-deltaic to lacustrine sediments

Along the Ubende belt, they probably

formed 2 major basin systems:

Kalemie-Lukuga -S.Tanganyika (KLT)

the Rukwa - Songwe – N. Malawi

(RSM) troughs.

Karoo basin system

in the Ubende Belt

Stratigraphy

of

Kayelekera

Geological map of the

eastern part of the

Tim Mersoï basin

(after Julia 1960) & 2003 airborne perimeter

from M. Souley, IAEA, 2005

STRATIGRAPHIC

CONTROLS

OF THE

LOCATION

OF THE

U – DEPOSITS

IN THE

TIM MERSOI

BASIN

West Air (Niger)

Parana

Karoo Precordilliera

Paganzo

Tarija

Gondwana

sedimentary basins

in South America

and Africa

Paraná Basin sedimentation

area covers > 1,700,000 km2

(Paraguay, Uruguay, Argentina,

Brazil)

It may have been interconnected

with the Karroo (in Africa),

Paganzo (Argentina), & Tarija

Basins (Argentina and Bolivia)

Parana basin

Sedimentary package deposited between

the Late Ordovician and the Late Cretaceous

Paganzo basin

(Argentina)

Carboniferous

to Permian

Tajira basin

(Argentina,

Bolivia)

Tajira basin stratigraphy

EW Koel-Damodar & NS Rajmahal

basins composed of separate outliers

arranged linearly

NW-SE Son-Mahanadi & Pranhita-

Godavari basins (PG) continuous of

outcrops

Son-Mahanadi (MR): funnel

shaped, narrow in SE & broad in NW

Pranhita-Godavari constant width

Satpura Gondwana basin to the NW

of Pranhita-Godavari basin is E-W

Mahadek Basin (to the NE) ?

Gondwana basins in India

Gondwana basins in Australia – Perth Basin

China

India

Gondwana basins in Australia – Perth Basin

PANGEA at 260 Ma

NCB=North China Block, SCB=South China Block, AI=Armorica, Avalonia & Iberia..

Modified from Meert (2012)