What kinds of rock is the grand canyon made up of?

Answer 1

The roots of the ancient mountain range that now lies at the bottom of the Grand Canyon were formed about 1.7 billion years ago. (my note: this layer is called the Vishnu Schist and is metamorphic; all younger layers are sedimentary rocks consisting of limestones, sandstones and shales, as follows)

There is then an unconformity of about 450 million year in which the rocks are missing.

At 1.25 billion years ago the first sedimentary layer, the Bass Formation, was laid down. Ancient coastal dwelling colonies of algae known as Stromatolites are preserved within this layer and indicate that the area was coastal at that time.

At 1.2 billion years ago the sea retreated leaving mud flats behind which eventually became the Hakatai Shale.

At 1.19 billion years a similar layer was deposited which is known as the Dox Formation. This was again formed of mudstones and shales and contains ripple marks as well as other features that indicate that it was close to the coast.

Between 1.25 and 1.1 billion years ago there was also some volcanic activity with the region of the Grand Canyon and this is when the Cardenas Basalts were formed.

Between 1 billion and 825 million years ago additional coastal and shallow sea formations, which are now classified as the Chuar group, were deposited.

There is then another unconformity of about 250 million years in which new rock layers were probably laid down but were completely eroded away.

The Tapeats Sandstone was then deposited around 550 million years ago along long vanished coastline. There are places in the Canyon in which in which off shore islands have been found imbedded within this layer.

The Bright Angel Shale was deposited around 540 million years ago and indicates that the ocean was again advancing.

The Muav Limestone was deposited around 530 million years ago at the bottom of a shallow sea.

The thick layer of Redwall Limestone which began to deposited around 330 million years ago indicates that the land was submerged for a great deal of time.

The Supai Group which rests atop the Redwall is dated at 300 million years ago and indicates that it was formed in an above water and coastal environment.

The Hermit Shale which was deposited around 280 million years ago contains many plant fossils which indicate that it was also above water.

The Coconino Sandstone represents the remains of a vast sea of sand dunes which was blown down from the north around 270 million years ago.

The layers found within Toroweap Formation contains both sandstone and limestone, indicating that it was sometimes coastal and sometimes submerged. These layers date to around 260 million years.

The top layer of the Grand Canyon, the Kaibab Limestone, contains many marine fossils which indicate that it originated at the bottom of the sea. This layer is around 250 million years old.

Rock layers younger than 250 million years have been eroded away and no longer exist in the immediate vicinity of the Grand Canyon.

Answer 2

The primary rock layers of the Grand Canyon are:

Kaibab Limestone
Toroweap Formation
Coconino Sandstone
Hermit Shale
Supai Formation
Redwall Limestone
Muav Limestone
Bright Angel Shale
Tapeats Sandstone
and
Vishnu Schist

Answer 3

The more general answer is sedimentary. Although as the previous answerer mentions the lower older levels are schist which is igneous in origin.