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You are possibly aware of plate tectonics, the surface of the earth is divided into a series of rigid plates of the lithosphere (the crust and upper part of the mantle). Example of one which is know well, the Pacific plate (ring of fire).
The different plates meet at plate boundaries, three major types, the one we are interested in, is the divergent boundary (plates move apart).
Such boundaries occur in mid oceans (mid-ocean ridges) and are associated with the addition of new crustal material from below the earth crust. As the crust moves away from the mid ocean ridge it becomes older. Therefore many million years ago the continental rocks were on the ocean bottom.
This is a simplistic answer and have not taken into account the other two very important types which also contribute, which form volcanoes and mountain.
As for the age of the sea floor would be in the order 125 to 200 million years old and the continental rocks in the order of a few billion years old.
What else can I help you with?
Which type of crust is heavier and younger?
Oceanic crust is heavier and younger compared to continental crust. It is denser because it is composed of basaltic rocks, while continental crust is made up of less dense granitic rocks. Additionally, oceanic crust is continually being formed at mid-ocean ridges through seafloor spreading, making it much younger on average than continental crust.
Why is the seafloor young?
The seafloor is continuously being created at mid-ocean ridges through seafloor spreading, where tectonic plates move apart and magma rises from the mantle to create new oceanic crust. As a result, the oldest seafloor is only about 200 million years old, much younger than continental crust which can be billions of years old.
Are rocks on the seafloor are much older than many continental rocks?
Yes, rocks on the seafloor are generally younger than many continental rocks. Seafloor rocks are primarily formed at mid-ocean ridges through volcanic activity and are continuously created and recycled through tectonic processes. In contrast, continental rocks can be much older, with some dating back billions of years, as they have remained largely stable and unaltered over geological time. Thus, while some individual seafloor rocks may be old, the majority are younger than the oldest continental rocks.
Are oceanic plates only made up of oceanic crust?
yes but oceanic crust is younger than continental crust because of deep sea trenches
How do the two types of crust vary?
Their main differences are in thickness, composition, density and age.Oceanic crust is thinner (5-10 km thick) than continental crust (20-70 km thick).Oceanic crust is composed of minerals that have higher concentrations of iron and magnesium (Mafic minerals) than those of the continental crust (which is richer in aluminum and silica - Felsic minerals).The rocks that make up the oceanic crust are typically more dense (3300 kg/m3) than those that make up the continental crust (2700 kg/m3).Oceanic crust is as a rule much younger than continental crust; the oldest oceanic crust is rarely over 200 million years in age, whereas the continental crust can exceed 3 billion years in age.
Which type of crust is heavier and younger?
Oceanic crust is heavier and younger compared to continental crust. It is denser because it is composed of basaltic rocks, while continental crust is made up of less dense granitic rocks. Additionally, oceanic crust is continually being formed at mid-ocean ridges through seafloor spreading, making it much younger on average than continental crust.
Oceanic crust is than continental crust.?
younger
Why is the seafloor young?
The seafloor is continuously being created at mid-ocean ridges through seafloor spreading, where tectonic plates move apart and magma rises from the mantle to create new oceanic crust. As a result, the oldest seafloor is only about 200 million years old, much younger than continental crust which can be billions of years old.
Differences of the continental crust and oceanic crust?
The continental crust is thicker, less dense, and older than the oceanic crust. It is composed mainly of granite rocks and is found beneath continental landmasses. In contrast, the oceanic crust is thinner, denser, and younger, with basalt rocks being the dominant rock type. It forms the ocean floor and is continually created and destroyed through the process of seafloor spreading and subduction.
What are the two types of crust that makes up the continents and ocean?
The two types of crust that make up the Earth's surface are continental crust and oceanic crust. Continental crust is thicker, less dense, and usually older than oceanic crust. Oceanic crust is thinner, more dense, and typically younger due to the process of seafloor spreading.
Why are there fewer large impact craters on the Earth's seafloor than on the continents?
The Earth's seafloor is constantly being renewed through processes like subduction and seafloor spreading, which can erase evidence of large impact craters over time. Additionally, water covers about 70% of the Earth's surface, increasing the likelihood of impacts occurring in the oceans rather than on land. As a result, large impact craters on the seafloor may be less visible or have been obscured by geological processes.
Oceanic crust is what than continental crust?
Oceanic crust is denser and thinner than continental crust. It is mainly composed of basalt, while continental crust is primarily made up of granite. Oceanic crust is also younger and constantly being formed at mid-ocean ridges through volcanic activity.
Which are younger old seafloor rocks or old continental rocks?
Old sea floor rocks are much younger than old continental rocks! This is because the oceanic lithospheric plate forming the seafloor tends to be recycled at places known as subduction zones where it is forced below less dense (commonly continental) lithosphere. As such the oldest continental rocks tend to be 2-3 billion years old whereas oceanic crust neve tends to be more than a few hundred million years old.
How does the density of oceanic crust differ from that of continental crust?
Oceanic crust is denser than continental crust because it is primarily composed of basalt, which is a mafic rock with a higher density than the felsic rocks that make up continental crust. Additionally, oceanic crust is thinner and younger than continental crust, contributing to its higher density.
What are the characteristics of the oceanic crust?
Oceanic crust is thinner and denser than continental crust, primarily composed of basaltic rock. It is typically younger due to the process of seafloor spreading, where new crust is formed at mid-ocean ridges and pushes older crust away. Oceanic crust is also more mafic in composition compared to continental crust.
What types of crust can be found in the lithosphere?
The lithosphere can have two main types of crust: continental crust and oceanic crust. Continental crust is thicker, older, and less dense than oceanic crust. Oceanic crust is thinner, younger, and denser, primarily composed of basaltic rocks.
Which type of crust is primarily made of basalt and is more dense?
Oceanic crust is primarily made of basalt and is more dense than continental crust. It is also younger and thinner compared to continental crust.
