Posted on April 18, 2022 (Updated on July 9, 2025)

What is spur in geology?

A spur is a lateral ridge or tongue of land descending from a hill, mountain or main crest of a ridge. It can also be defined as another hill or mountain range which projects in a lateral direction from a main hill or mountain range.

What is a geological spur?

A spur is a long, gently-sloping ‘tongue’ of ground that runs down from a hill to lower ground. Spurs often provide access to and from the high ground, for walkers, for roads, etc.

What is valley and spur?

A spur is formed between two river valleys. In the case of a river valley, the greatest height is to the outer side and the land sinks down towards the inner side, where the riverbed is. In the case of a spur, the greatest height is to the inner side and the land sinks down towards the outer side of the spur.

What is the difference between ridge and spur?

Ridge (Also: Arete or Spur) – A continuous elevated terrain with sloping sides. In the map represented by “U” or “V” shaped contour lines where the higher ground is in the wide opening. Arete is a narrow ridge and a Spur is a smaller ridge branching off a summit or a main ridge.

What is a spur place?

Sput definition

An annular reinforcement in a steam boiler, to strengthen a place where a hole is made.

What is a spur in river?

Spurs are river engineering elements used to protect river banks from erosion and to concentrate flow to the river axis. Today, spurs are also employed for promoting environmental conditions along a river bank.

What is ridge in geology?

A ridge or a mountain ridge is a geographical feature consisting of a chain of mountains or hills that form a continuous elevated crest for an extended distance. The sides of the ridge slope away from the narrow top on either side.

What is fractionated plateau?

The fractioned plateau is the longest mountain chain on the earth’s surface which is submerged under the sea. It is characterized by a central rift system at the crest.

What is the difference between a ridge and a valley?

Ridge (Also: Arete or Spur) – A continuous elevated terrain with sloping sides. A valley can be “V” or “U” shaped and often can be seen as a “negative” to a ridge. On a map, valleys are represented by the same contour shape as ridges with the difference being the the wide openings are at lower elevation.

What is flank zone?

The flanks are marked by sets of mountains and hills that are elongate and parallel to the ridge trend. transform faults. Oceanic ridges offset by transform faults and fracture zones.

How do ridges form?

A mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics. This uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.

What are the types of ridges?

Friction ridge patterns are grouped into three distinct types—loops, whorls, and arches—each with unique variations, depending on the shape and relationship of the ridges: Loops – prints that recurve back on themselves to form a loop shape.

What is the oceanic crust?

Oceanic crust is the part of the Earth’s crust that makes up the seafloor. It’s thinner, denser, and simpler in structure than the continental crust. Oceanic crust is also younger, on average; from its birth at a mid-ocean ridge to its end at a subduction zone is no more than 250 million years.

Why is oceanic crust basaltic?

Magmas generated by melting of Earth’s mantle rise up below the oceanic crust and erupt on Earth’s surface at mid-ocean ridge systems, the longest mountain ranges in the world. When the magma cools it forms basalt, the planet’s most-common rock and the basis for oceanic crust.

Why is ocean crust thin?

The oceanic crust is thin, relatively young and uncomplicated compared to the continental crust, and chemically magnesium-rich compared to continental material. The oceanic crust is the product of partial melting of the mantle at the mid-ocean ridges: it is the cooled and crystallized melt fraction.

Why is oceanic crust denser?

Why is the oceanic crust more dense? Oceanic crust is denser because it generally melts to a higher fraction than continental crust. When rocks melt to 20–30% like they do at mid-ocean ridges, the result is more dense than when rocks melt to form continental plates, which is typically 1–5%.

What crust is thicker?

continental crust

Earth’s crust is generally divided into older, thicker continental crust and younger, denser oceanic crust.

Is continental crust made of basalt?

Origin. All continental crust is ultimately derived from mantle-derived melts (mainly basalt) through fractional differentiation of basaltic melt and the assimilation (remelting) of pre-existing continental crust.

What is the only liquid layer inside the Earth?

The outer core

The outer core is the liquid largely iron layer of the earth that lies below the mantle. Geologists have confirmed that the outer core is liquid due to seismic surveys of Earth’s interior. The outer core is 2,300 km thick and goes down to approximately 3,400 km into the earth.

What is the hottest layer of the earth?

the inner core

The core is the hottest, densest part of the Earth. Although the inner core is mostly NiFe, the iron catastrophe also drove heavy siderophile elements to the center of the Earth.

Which is the thinnest layer of the earth?

the crust

Discuss with the whole class what the relative thicknesses of the layers are — that the inner core and outer core together form the thickest layer of the Earth and that the crust is by far the thinnest layer.

Which is the last layer of the earth?

Exosphere. Although some experts consider the thermosphere to be the uppermost layer of our atmosphere, others consider the exosphere to be the actual “final frontier” of Earth’s gaseous envelope.

What is third layer of Earth?