Samarkand is smaller in size than Tashkent.
1) Divergent boundaries because they cause new crust to form.
2) MORS are underwater mountain ranges that rise to connect with the continents and form new crust. The lava gets pushed under the oceanic crust.
Explanation:
Serpentine
- Formation: it forms through serpentinization, a geological low-temperature metamorphic process where low-silica mafic and ultramafic rocks are oxidized and hydrolyzed with water into serpentinite.
- Characteristics: rich in magnesium and water, light to dark green, greasy-looking and slippery feeling. It can resist the transfer of heat. A source of asbestos, architectural stone, ornamental stone, gem material
- Minerals present: it follows the formula (X)2-3(Y)2O5(OH)4 where X can be magnesium, iron, nickel, aluminum, zinc, or manganese; and, Y will be silicon, aluminum, or iron.
Green Schist
- Formation: they form by regional metamorphism of mafic igneous rocks through depth of burial, and proximity to batholiths.
- Characteristics: The green is due to abundant green chlorite
- Minerals present: actinolite and epidote mainly, but they can also include quartz, orthoclase, talc, carbonate minerals, and amphibole.
Basalt Pillow
- Formation: it forms when lava of basaltic compositions erupted underwater. The rapid cooling of the lava forms the pillow-shaped bodies.
- Characteristics: they are volcanic igneous rocks, very dark, almost black color.
- Minerals present: Basalt has a lower percentage of silica and a higher percentage of iron and magnesium than other volcanic rocks.
Umber
- Formation: it develops in Cyprus massive sulfide deposits.
- Characteristics: is not one precise color, but a range of different colors, from medium to dark, from yellowish to reddish to grayish depending on the iron oxide and manganese in the clay
- Minerals present: contains iron oxide and manganese oxide and sulfide precipitates like pyrite.
I hope you find this information useful and interesting! Good luck!
Answer:
Convergent and divergent plate boundaries
Explanation:
In a convergent plate boundary, two plates move towards each other. Due to the impact, the heavier tectonic plate subducts beneath the lighter plate. This results in the formation of a subduction zone, and there forms a trench above this zone. The rocks at greater depths, melts and mixes up with the magma and eventually rises upward, towards the surface in the over-riding plate, giving rise to the formation of volcanoes and volcanic arcs.
In a divergent plate boundary, two plates move away from one another. Due to this opposite motion of plates, there occur cracks on the seafloor and land areas, from where the magma comes out. With continuous spreading, there forms a ridge, which is commonly known as the mid-oceanic ridge. This type of plate boundary is responsible for the formation and expansion of the ocean basin. For example, the mid-Atlantic ridge.
