Minor plate that separated from Gondwana
This article is about the geological term. For the large plated meal in Indian restaurants, see
Thali
.
The
Indian Plate
(or
India Plate
) is a
minor tectonic plate
straddling the
equator
in the
Eastern Hemisphere
. Originally a part of the ancient continent of
Gondwana
, the Indian Plate broke away from the other fragments of Gondwana
100
million years ago
and began moving north, carrying
Insular India
with it.
[2]
It was once fused with the adjacent
Australian Plate
to form a single
Indo-Australian Plate
; recent studies suggest that India and Australia have been separate plates for at least 3 million years.
[3]
The Indian Plate includes most of modern
South Asia
(the
Indian subcontinent
) and a portion of the basin under the
Indian Ocean
, including parts of
South China
, western
Indonesia
,
[4]
[5]
and extending up to but not including
Ladakh
,
Kohistan
, and
Balochistan
.
[6]
[7]
[8]
Plate movements
[
edit
]
Due to
plate tectonics
, Insular India, situated over the Indian plate, split from Madagascar and collided (c. 55 Mya) with the
Eurasian Plate
, resulting in the formation of the
Himalayas
.
Until roughly
140
million years ago
, the Indian Plate formed part of the
supercontinent
,
Gondwana
, together with modern Africa, Australia, Antarctica, and South America. Gondwana fragmented as these continents drifted apart at different velocities;
[9]
a process which led to the opening of the
Indian Ocean
.
[10]
In the late
Cretaceous
approximately
100
million years ago
, and subsequent to the splitting from
Gondwana
of conjoined
Madagascar
and
India
, the Indian Plate split from Madagascar and formed
Insular India
. It began moving north, at about 20 cm (7.9 in) per year,
[9]
and is believed to have begun colliding with Asia as early as
55
million years ago
,
[11]
in the
Eocene
epoch of the
Cenozoic
. However, some authors suggest the collision between India and Eurasia occurred much later, around
35
million years ago
.
[12]
If the collision occurred between 55 and 50 Mya, the Indian Plate would have covered a distance of 3,000 to 2,000 km (1,900?1,200 mi), moving more quickly than any other known plate. In 2012,
paleomagnetic
data from the Greater Himalaya was used to propose two collisions to reconcile the discrepancy between the amount of crustal shortening in the Himalaya (~1,300 km or 800 mi) and the amount of convergence between India and Asia (~3,600 km or 2,200 mi).
[13]
These authors propose a continental fragment of northern Gondwana rifted from India, traveled northward, and initiated the "soft collision" between the Greater Himalaya and Asia at ~50 Mya. This was followed by the "hard collision" between India and Asia occurred at ~25 Mya.
Subduction
of the resulting ocean basin that formed between the Greater Himalayan fragment and India explains the apparent discrepancy between the crustal shortening estimates in the Himalaya and paleomagnetic data from India and Asia. However, the proposed ocean basin was not constrained by paleomagnetic data from the key time interval of ~120 Mya to ~60 Mya. New paleomagnetic results of this critical time interval from southern Tibet do not support this Greater Indian Ocean basin hypothesis and the associated dual collision model.
[14]
In 2007, German geologists
[9]
suggested the reason the Indian Plate moved so quickly is that it is only half as thick (100 km or 62 mi) as the other plates
[15]
which formerly constituted Gondwana. The
mantle plume
that once broke up Gondwana might also have melted the lower part of the
Indian subcontinent
, which allowed it to move both more quickly and farther than the other parts.
[9]
The remains of this plume today form the
Marion Hotspot
(
Prince Edward Islands
), the
Kerguelen hotspot
, and the
Reunion hotspots
.
[10]
[16]
As India moved north, it is possible the thickness of the Indian Plate degenerated further as it passed over the hotspots and magmatic extrusions associated with the
Deccan
and
Rajmahal Traps
.
[10]
The massive amounts of
volcanic gases
released during the passage of the Indian Plate over the hotspots have been theorised to have played a role in the
Cretaceous?Paleogene extinction event
, generally held to be due to a
large asteroid impact
.
[17]
In 2020, however, geologists at the
University of Oxford
and the
Alfred Wegener Institute
found that new plate-motion models displayed increased movement speeds in all
mid-ocean ridges
during the late Cretaceous, a result irreconcilable to current theories of plate tectonics and a refutation of the plume-push hypothesis. Perez-Diaz concludes that the accelerated movement of the Indian Plate is an illusion wrought by large errors in
geomagnetic reversal timing
around the
Cretaceous?Paleogene boundary
, and that a recalibration of the time scale shows no such acceleration exists.
[18]
[19]
The collision with the
Eurasian Plate
along the boundary between India and
Nepal
formed the
orogenic belt
that created the
Tibetan Plateau
and the
Himalaya
Mountains, as sediment bunched up like earth before a
plow
.
The Indian Plate is currently moving north-east at five cm (2.0 in) per year, while the Eurasian Plate is moving north at only two cm (0.79 in) per year. This is causing the Eurasian Plate to deform, and the Indian Plate to compress at a rate of four mm (0.16 in) per year.
[
citation needed
]
Geography
[
edit
]
The westerly side of the Indian Plate is a transform boundary with the
Arabian Plate
called the
Owen Fracture Zone
, and a
divergent boundary
with the
African Plate
called the
Central Indian Ridge
(CIR). The northerly side of the Plate is a
convergent boundary
with the
Eurasian Plate
forming the
Himalaya
and
Hindu Kush
mountains
, called the
Main Himalayan Thrust
.
[
citation needed
]
See also
[
edit
]
Notes
[
edit
]
- ^
"Sizes of Tectonic or Lithospheric Plates"
. Geology.about.com. 2014-03-05
. Retrieved
2016-01-13
.
- ^
Oskin, Becky (2013-07-05).
"New Look at Gondwana's Breakup"
. Livescience.com
. Retrieved
2016-01-13
.
- ^
Stein, Seth; Sella, Giovanni F.; Okai, Emile A. (2002).
"The January 26, 2001 Bhuj Earthquake and the Diffuse Western Boundary of the Indian Plate"
(PDF)
.
Geodynamics Series
. American Geophysical Union: 243?254.
doi
:
10.1029/GD030p0243
.
ISBN
9781118670446
. Retrieved
2015-12-25
.
- ^
Sinvhal,
Understanding Earthquake Disasters
, p. 52, Tata McGraw-Hill Education, 2010,
ISBN
978-0-07-014456-9
- ^
Kumar, M. Ravi; Bhatia, S. C. (1999). "A new seismic hazard map for the Indian plate region under the global seismic hazard assessment programme".
Current Science
.
77
(3): 447.
JSTOR
24102967
.
- ^
M. Asif Khan,
Tectonics of the Nanga Parbat syntaxis and the Western Himalaya
, p. 375, Geological Society of London, 2000,
ISBN
978-1-86239-061-4
- ^
Srikrishna Prapnnachari,
Concepts in Frame Design
, page 152, Srikrishna Prapnnachari,
ISBN
978-99929-52-21-4
- ^
A. M. Celal ?engor,
Tectonic evolution of the Tethyan Region
, Springer, 1989,
ISBN
978-0-7923-0067-0
- ^
a
b
c
d
Kind 2007
- ^
a
b
c
Kumar et al. 2007
- ^
Scotese 2001
- ^
Aitchison, Ali & Davis 2007
- ^
van Hinsbergen, D.; Lippert, P.; Dupont-Nivet, G.; McQuarrie, N.; Doubrivine, P.; Spakman, W.; Torsvik, T. (2012).
"Greater India Basin hypothesis and a two-stage Cenozoic collision between India and Asia"
.
Proceedings of the National Academy of Sciences
.
109
(20): 7659?7664.
Bibcode
:
2012PNAS..109.7659V
.
doi
:
10.1073/pnas.1117262109
.
PMC
3356651
.
PMID
22547792
.
- ^
Qin, Shi-Xin; Li, Yong-Xiang; Li, Xiang-Hui; Xu, Bo; Luo, Hui (2019-01-17). "Paleomagnetic results of Cretaceous cherts from Zhongba, southern Tibet: New constraints on the India-Asia collision".
Journal of Asian Earth Sciences
.
173
: 42?53.
Bibcode
:
2019JAESc.173...42Q
.
doi
:
10.1016/j.jseaes.2019.01.012
.
ISSN
1367-9120
.
S2CID
134469511
.
- ^
The lithospheric roots in South Africa, Australia, and Antarctica are 300 to 180 km (190 to 110 mi) thick. (
Kumar et al. 2007
) See also
Kumar et al. 2007
,
figure 1
- ^
Meert, J.G.; Tamrat, Endale (2006). "Paleomagnetic evidence for a stationary Marion hotspot: Additional paleomagnetic data from Madagascar".
Gondwana Research
.
10
(3?4): 340?348.
Bibcode
:
2006GondR..10..340M
.
doi
:
10.1016/j.gr.2006.04.008
.
- ^
Schulte, Peter; et al. (5 March 2010).
"The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous-Paleogene Boundary"
(PDF)
.
Science
.
327
(5970). AAAS: 1214?1218.
Bibcode
:
2010Sci...327.1214S
.
doi
:
10.1126/science.1177265
.
ISSN
1095-9203
.
PMID
20203042
.
S2CID
2659741
.
- ^
Perez-Diaz, L.; Eagles, G.; Sigloch, K. (2020).
"Indo-Atlantic plate accelerations around the Cretaceous-Paleogene boundary: A time-scale error, not a plume-push signal"
.
Geology
.
48
(12): 1169?1173.
Bibcode
:
2020Geo....48.1169P
.
doi
:
10.1130/G47859.1
.
- ^
Andrews, Robin George (14 April 2021).
"The New Historian of the Smash That Made the Himalayas"
.
Quanta Magazine
. Retrieved
15 April
2021
.
References
[
edit
]
- Aitchison, Jonathan C.; Ali, Jason R.; Davis, Aileen M. (2007).
"When and where did India and Asia collide?"
.
Journal of Geophysical Research
.
112
(B5): B05423.
Bibcode
:
2007JGRB..112.5423A
.
CiteSeerX
10.1.1.1008.2522
.
doi
:
10.1029/2006JB004706
.
hdl
:
10722/72794
.
ISSN
0148-0227
. Retrieved
January 12,
2016
.
- Chen, Ji (January 4, 2005).
"Magnitude 9.0 off W coast of northern Sumatra Sunday, December 26, 2004 at 00:58:49 UTC: Preliminary rupture model"
.
U.S. Geological Survey
. Archived from
the original
on March 5, 2005
. Retrieved
28 December
2004
.
- Kind, Rainer (17 October 2007).
"The fastest continent: India's truncated lithospheric roots"
(Press release). Helmholtz Association of German Research Centres
. Retrieved
2 October
2019
.
- Kumar, Prakash; Yuan, Xiaohui; Kumar, M. Ravi; Kind, Rainer; Li, Xueqing; Chadha, R. K. (18 October 2007).
"The rapid drift of the Indian tectonic plate"
.
Nature
.
449
(7164): 894?897.
Bibcode
:
2007Natur.449..894K
.
doi
:
10.1038/nature06214
.
ISSN
0028-0836
.
PMID
17943128
.
S2CID
4339656
.
- Scotese, Christopher R. (January 2001).
"The collision of India and Asia (90 mya ? present)"
. Paleomap Project
. Retrieved
28 December
2004
.
External links
[
edit
]