Ages of the igneous rocks range from 70 to 74 million years.

He noted significant problems with the current classification systems for igneous rocks.

These igneous rocks are some 390 million years old.

Ages of these igneous rocks fall in the interval 25 to 28 million years.

Subsequently the name was given to igneous rocks with large crystals.

Evolved igneous rocks are much less common on cold, dead bodies such as the Moon.

He was noted for his study of silicates and igneous rocks.

Most major igneous rocks are found along this scale.

They occur in rare and unusual types of igneous rocks.

The area near the mine contains sedimentary and igneous rocks.

The second approach was by isotopic age dating of the igneous rocks.

Igneous rocks can be classified according to their chemistry.

Many and peculiar are the classifications that have been proposed for igneous rocks.

These elements are major components of the minerals comprising igneous rocks.

Igneous rocks such as granite and basalt also often form cliffs.

Igneous rocks make up over 90% of the Earth's crust by volume.

The polarity of the Earth's magnetic field is recorded in igneous rocks.

They are the oldest igneous rocks, with crystallization ages of around 4.55 billion years.

Quartz veins and igneous rocks form most of its geology.

We will classify igneous rocks on the basis of texture and composition.

"But a geological oddity, to say the least, especially in igneous rocks.

These formed hard igneous rocks which have resisted erosion.

Igneous rocks, said a remote corner of Jon's mind.

Silica-saturated igneous rocks fall in between these two classes.

These unusual igneous rocks are some of the youngest in eastern North America.

The settlement is built on a large amount of igneous rock.

Ages of the igneous rocks range from 70 to 74 million years.

Intrusions are one of the two ways igneous rock can form.

He noted significant problems with the current classification systems for igneous rocks.

These igneous rocks are some 390 million years old.

Ages of these igneous rocks fall in the interval 25 to 28 million years.

Subsequently the name was given to igneous rocks with large crystals.

Huge walls of igneous rock, some about 250 feet high, rise above the falls on both sides.

Evolved igneous rocks are much less common on cold, dead bodies such as the Moon.

He was noted for his study of silicates and igneous rocks.

Most major igneous rocks are found along this scale.

Obsidian is a natural volcanic glass found as a kind of igneous rock.

Igneous rock is hardened magma, which can happen above or below ground.

Crystal shape is also an important factor in the texture of an igneous rock.

Two different groups of igneous rock have been found within Alexander Island.

They occur in rare and unusual types of igneous rocks.

Igneous rock is rock that has been made by volcanic action.

The area near the mine contains sedimentary and igneous rocks.

The second approach was by isotopic age dating of the igneous rocks.

It is an igneous rock, formed from volcanic action.

When it has stopped moving, lava solidifies to form igneous rock.

Granite makes up the bulk of the igneous rock.

Igneous rock flowed up into fissures, as a new ocean began to form.

Also in certain sections of the region, we can find granite, which is an intrusive igneous rock.

Igneous rocks can be classified according to their chemistry.