Stratigraphy and paleogeography of Gondwana · PDF fileStratigraphy and paleogeography of...
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Stratigraphy and paleogeography of
Gondwana
GéoRessources - CREGU - CNRS UNIVERSITE DE LORRAINE
54 506, Vandoeuvre les NANCY FRANCE Vienna 06-2015 – Karoo U Basins [email protected]
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)