Valcanoes Flashcards
(78 cards)
Vent or opening on the surface of the earth
Valcanoes
Difference between volcano and valcanicity
Valcano is just a opening, where as valcanicity is a broad term,
Valcanicity means the exogenic and endogenic process acting i.e, exogenic -> outpouring of lava, endogenic implies magma or molten material.
Materials erupted during valcanoic emission
Water vapour and gases,
Magma and lava,
Fragmental materials
% of water vapour in valcanoic water vapour and gases
60-90%
Gases that come out of valcano
Sulphur dioxide,
Nitrous dioxide,
Carbon dioxide and monoxide both
Difference between magma and lava
Molten rock material inside the earth surface is called magma and which comes out is called lava
What is basic and what is acidic in magma and lava
Lava is acidic and magma is basic and
By this we can say that granite is formed in lava and basalt Is formed in magma,
Basalt is highly denser so a bit fine grained, while granite is less denser so a bit corrosive,
Remember these words:
Plutonic, hypabassal, extrusive,
Pegmatic, pheneratic, aphantic, glassy
Fragmentic materials formed during valcanoic eruption are
Volcanoic dust,
Volcanoic ash, lapilli,
Valcanoic bombs
Volcanic eruption is due to ? And which theory explains it
Plate techtonic theory explains it, due to destructive and constructive plate boundaries
What happens in destructive plate boundaries ?
Collision of two plates, the heavier plate goes below the lighter plate and the subduction zone is formed.
The heavier plate which went down gets melted and the magma rises upwards.
Magma thus rises upwards and blows away forming a volcanic eruption.
Destructive plate boundaries causes volcanoes and where can we see them, in the case of mountain ranges
Fold mountains are the best source of the destructive volcanic eruption.
80% of worlds volcanoes are due to constructive or destructive ?
Constructive
What happens in convergent plates in volcano
Convergent have the constant supply of material for the magma formation, so there is a continuous eruption, these causes a bit low intense eruptions,
these eruptions are called as fissure volcanic eruptions,
Fissure volcanic eruptions are seen in? Convergent or divergent, mention any example
Divergent i.e constructive and example is mid oceanic ridge
What are volcanic hotspots
Areas of active volcanic eruptions, continuous supply of magma, these are not associated with plate boundaries, they are intra plate
what are intra plate volcanoes?
Volcanic hotspots
Example of volcanic hotspots
Reunion hotspot and Hawaii island
what is reunion hotspot
It helped in the formation of black cotton soil in India
Mention the world distribution of volcanoes, i,e types of volcanoes
Circum pacific belt,
Mid Atlantic belt,
Mid continental belt,
Region of volcanic hotspots
Types of volcanic landforms
Intrusive And extrusive
Difference between intrusive and extrusive volcanic landforms
Intrusive here the magma gets cooled below the surface of the earth in extrusive magma gets converted to lava and gets cooled.
In - have larger crystals, Ex - Have smaller crystals.
Larger crystals meant granite and smaller crystals meant basalt,
Intrusive are further divided into plutonic and hypabassal
So difference between plutonic and hypabassal land forms
Plutonic is formed deep inside and hypabassal is formed just below the surface.
Types of intrusive land forms
Batholith - large mass of all the below,
Sill - forms in horizontal like parallel to bedding plain in sedimentary rocks,
Dykes - perpendicular to the bedding plain,
Lopolith - present in the shape of saucer or bent shaped.
Laccolith - mushroom shaped.
Phacolith - lens shaped which occupy anticline and syncline
Features of batholith
It’s the biggest and deepest of all