Thses Ppt is about mineral Resources of indian ocean

1. Chemistry of Oceanic
Rocks And Mineral
Resources Of The
Indian Ocean
Paper: Geology 508
Supervision: Dr. H.V Majethiya
M.G. Science Institute
(Geology Department)
Name: Akash Limbachiya
Roll No: 04
M.Sc.- Semester:4

2. Chemistry of Ocenic Rocks
 Oceanic crust, the outermost layer of Earth’s lithosphere that
is found under the oceans and formed at spreading centres
on oceanic ridges, which occur at divergent plate boundaries.
 Oceanic crust is about 6 km (4 miles) thick. It is composed of
several layers, not including the overlying sediment. The
topmost layer, about 500 metres (1,650 feet) thick, includes
lavas made of basalt (that is, rock material consisting largely
of plagioclase [feldspar] and pyroxene).
 Oceanic crust differs from continental crust in several ways: it
is thinner, denser, younger, and of different chemical
composition. Like continental crust, however, oceanic crust is
destroyed in subduction zones.

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 The lavas are generally of two types: pillow lavas and sheet flows.
Pillow lavas appear to be shaped exactly as the name implies—
like large overstuffed pillows about 1 metre (3 feet) in cross
section and 1 to several metres long.
 On the East Pacific Rise at 8° S latitude, a series of sheet flow
eruptions (possibly since the mid-1960s) have covered more than
220 square km (85 square miles) of seafloor to an average depth
of 70 metres (230 feet).
 These gabbro layers are thought to represent the magma
chambers, or pockets of lava, that ultimately erupt on the seafloor.
The upper gabbro layer is isotropic (uniform) in structure.
 In some places this layer includes pods of plagiogranite, a
differentiated rock richer in silica than gabbro

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The layers in the cumulate gabbro have less silica but are
richer in iron and magnesium than the upper portions of the
crust. Olivine, an iron-magnesium silicate, is a common
mineral in the lower gabbro layer.
Mantle rock is composed mostly of peridotite, which consists
primarily of the mineral olivine with small amounts of
pyroxene and amphibole.

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https://opentextbc.ca//

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Layer 1 is on an average 0.4 km thick. It consists of
unconsolidated or semiconsolidated sediments,
usually thin or even not present near the mid-ocean
ridges but thickens farther away from the ridge. Near
the continental margins sediment is terrigenous,
meaning derived from the land, unlike deep sea
sediments which are made of tiny shells of marine
organisms, usually calcareous and siliceous, or it can
be made of volcanic ash and terrigenous sediments
transported by turbidity currents.

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 Layer 2 could be divided into two parts: layer 2A – 0.5 km thick
uppermost volcanic layer of glassy to finely
crystalline basalt usually in the form of pillow basalt, and layer
2B – 1.5 km thick layer composed of diabase dikes.
 Layer 3 is formed by slow cooling of magma beneath the
surface and consists of coarse
grained gabbro and cumulate ultramafic rocks. It constitutes
over two-thirds of oceanic crust volume with almost 5 km
thickness.

8.  Oceans cover 70 percent of Earth's surface, host a vast variety of
geological processes responsible for the formation and
concentration of mineral resources, and are the ultimate repository
of many materials eroded or dissolved from the land surface.
 Today, direct extraction of resources is limited to salt; magnesium;
placer gold, tin, titanium, and diamonds; and freshwater.
 The limitations on extraction of the dissolved elements as well as the
extraction of solid mineral resources are nearly always economic,
but may also be affected by geographic location (ownership and
transport distance) and hampered by technological constraints
(depth of ocean basins).
 The principal mineral resources presently being extracted and likely
to be extracted in the near future are briefly considered here.
Mineral Resources of The Indian
Ocean

9. Salt
https://en.m.wikipedia.org/wiki/Sea_salt

10. Magnese Nodules
https://m.economictimes.com/news/economy/policy/government-to-
extend-pact-with-isa-on-exploring-manganese-nodules/

11. Phosphorites
https://en.m.wikipedia.org/wiki/Phosphorite

12. Sand and Gravel
https://en.m.wikipedia.org

13. Metal Deposits Associated with volcanism
and seafloor vents
https://www.researchgate.net/figure/

14. Magnesium
https://en.m.wikipedia.org

15. Limestone and Gypsum
https://www.dreamstime.com/

16. Reference
 http://en.wikipedia.org
www.geoscience.co.in
 Indian’s Mineral’s Resource's 2nd Edition (S. Krishanswamy)
 https://www.britannica.com/place/Indian-Ocean/Economic-
aspects

17. THANK YOU