SELF-ORGANIZED BREAKUP OF GONDWANA
byJIM SEARS
UNIVERSITY OF MONTANA
MAIN CONCLUSIONS:
BREAKUP OF GONDWANA WAS SELF-ORGANIZED TO MINIMIZE
WORK
ARGUES AGAINST DEEP MANTLE PLUMES
HEARD ISLAND HOT SPOT
THE DEEP MANTLE PLUME PARADIGM: AN INTEGRAL PART OF PLATE TECTONICS SINCE
J.T. WILSON (1963) AND W.J. MORGAN (1981)
STATIONARY HOT SPOT VOLCANOES:TAILS OF DEEP MANTLE PLUMES?
LARGE IGNEOUS PROVINCES (LIPS): HEADS OF DEEP MANTLE PLUMES?
HEADS AND TAILS LINKED BY HOT SPOT TRACKS?
PLUMES RANDOMLY GENERATED AT CORE-MANTLE BOUNDARY?
PLUME OUTBREAKS INITIATE CONTINENTAL BREAKUP?
GONDWANA
AUST
ANTARCTICA
NZ
AF
SA
INDIA
1999 UTIG
ACCEPTED MODEL FOR GONDWANA BREAKUPLAWVER ET AL. 1999
CAMP - FERNANDO
1999 UTIG
KAROO-BOUVET
1999 UTIG
GALLODAI-MARION
1999 UTIG
PARANA-TRISTAN
1999 UTIG
RAJMAHAL-KERGUELEN
BANBURY-HEARD
1999 UTIG
HOTSPOT CONSTELLATION
AFRICA
SOUTHAMERICA
INDIA
ARABIA
ANTARCTICA
AU
STR
ALI
A
N Z
HOWEVER, BREAKUP OF GONDWANA WAS NOT
RANDOM - IT WAS HIGHLY SELF-ORGANIZED
FLO
RID
A
ETHIOPIAN
38 Ma
LARGE IGNEOUS PROVINCES
DECCAN65 Ma
RAJMAHAL
110 Ma
PARANA 134 Ma
GALLODAI144 MaKAROO
183 Ma
FERRAR183 Ma
CAMP 205 Ma
LIMPOBO
TRANSKEI
MARANHAO 200 Ma
GONDWANA HOT SPOT FAMILY
HEARD
ST HELENA
MARION
BOUVETFERNANDO
TRISTAN
GOUGH
CROZETKERGUELE
NASCENCION
THESE MAJOR GONDWANA
FRACTURE POLYGONS RIGOROUSLY OBEY EULER’S THEOREM
FOR CONVEX POLYTOPES
BEN
UE
TA
CU
TU
GO
DAV
AR
I
WED
ELL
TRANSKEI
PER
U-P
ARAGUAY
DIS
CONTI
NUIT
Y
NAMELY, TO TILE A SPHERE WITH 12 +
PLATES, 12 MUST HAVE 5-FOLD SYMMETRY AT PRECISELY-DEFINED
VERTICES OF ICOSAHEDRON
GONDWANA
REMAINING (N-12) PLATES HAVE 6-
FOLD SYMMETRY
GONDWANA
Euler’s formula relating faces (F), vertices (V ), and edges (E) of a convex polytope (F + V = E + 2)
ICOSAHEDRAL ARRANGEMENTS
ICOSAHEDRAL VIRUS
HERPES SIMPLEX
FINITE ELEMENT SOLUTION FOR
THOMSON PROBLEM WITH 912
CHARGES ON SPHERE
(Altschuler et al., 1997)
EDGE LENGTHS AND CENTERS
ARE RIGOROUSLY DEFINEDEACH EDGE = 2600 KM AT
EARTH SCALE
GONDWANA
ANTARCTICA
PENTAGONRIFT EDGES ~
2600 KM
2600
KM
2600 KM 2600 KM
GONDWANA
PENTAGONS AND HEXAGONS IN EXACT ARRANGEMENT
PP
H
H
HH
H
P
GONDWANA
PP
H
H
HH
H
P
16 EDGES,>20,000 KM
PATTERN MINIMIZES TOTAL FRACTURE LENGTHAND THEREFORE MINIMIZES WORK
FUNCTION OF STRENGTH OF GONDWANA SHELL
GONDWANA
STRONGER
WEAKER
GONDWANA
PATTERN MINIMIZES TOTAL FRACTURE LENGTHAND THEREFORE MINIMIZES WORK
FUNCTION OF STRENGTH OF GONDWANA SHELL
GONDWANA
STRONGER
WEAKER
GONDWANAX
LARGE IGNEOUS PROVINCES ERUPTED DIACHRONOUSLY ALONG FRACTURE
PATTERN
DEPENDED ON PLATE TECTONICS TO OPENFRACTURES TO INDUCE DECOMPRESSION
MELTING
CONCORDANCE OF FAMILY OF HOT SPOTS WITH FRACTURE TESSELLATION
SHOWS HOT SPOTS ARE NON-RANDOM
HOTSPOTS ON TESSELLATION
YELLOW STRESS TESSELLATION IS DUAL OF FRACTURE TESSELLATION:
THEY CROSS ONE ANOTHER ORTHOGONALLY
HOTSPOTS ON TESSELLATION
HOOP STRESS ALONG NORTHERN GONDWANA MARGIN
NOTE RADIAL FRACTURES AT MARGIN
HOTSPOTS ON TESSELLATION
NOTE PERFECT SYMMETRY OF STRESS TESSELLATION ACROSS
GONDWANA
HOTSPOTS FAVOR CENTERS
EXPANSION OF GONDWANA LEADS TO FRACTURES
FRACTURE SYSTEM INDICATES GONDWANA WAS UNDER UNIFORM TENSION
HOTSPOTS ON TESSELLATION
NOTE SYMMETRY OF STRESS TESSELLATION ACROSS GONDWANA
INITIAL GEOMETRY OF GONDWANA DETERMINED BEST ORIENTATION OF TESSELLATION TO
ACHIEVE MINIMUM FRACTURE LENGTH
AND THEREFORE LEAST WORK
HOTSPOTS ON TESSELLATION
AFRICAN GEOID ANOMALYSYMMETRICAL TO FRACTURES
WHEN GONDWANA IS RESTORED TO TRIASSIC POSITION
HOTSPOTS ON TESSELLATION
GONDWANA SPREAD OUTWARD DOWN GEOID GRADIENT
SEE ANDERSON, 1982
GONDWANA STALLED ON MANTLE FRAMEWORKGONDWANA STALLED ON MANTLE FRAMEWORKINSULATED UNDERLYING MANTLEINSULATED UNDERLYING MANTLE
THERMAL EXPANSION OF MANTLE DROVE UPLIFT THERMAL EXPANSION OF MANTLE DROVE UPLIFT AND UNIFORM TENSION IN GONDWANAAND UNIFORM TENSION IN GONDWANA
FRACTURE TESSELLATION OCCURRED AT CLIMAX FRACTURE TESSELLATION OCCURRED AT CLIMAX OF UPLIFT, IN EARLY TRIASSICOF UPLIFT, IN EARLY TRIASSIC
FRACTURES LATER SEPARATED AS REQUIRED BY FRACTURES LATER SEPARATED AS REQUIRED BY PLATE TECTONICS, DRIVING DECOMPRESSION PLATE TECTONICS, DRIVING DECOMPRESSION
MELTING MELTING