BUSHVELD IGNEOUS COMPLEX

Feature

Details

About

It  is the largest layered igneous intrusion within the Earth's crust. The site was first publicised around 1897 by Gustaaf Molengraaff who found the native South African tribes residing in and around the area.  This is the oldest example of living microbes found within ancient rock to date.

It has been tilted and eroded forming the outcrops around what appears to be the edge of a great geological basin: the Transvaal Basin.  

Location

Northern South Africa, exposed at the edge of the Transvaal Basin.

Formation Age

It is approximately two billion years old and is divided into four limbs: northern, eastern, southern, and western.

Formation Process

Molten rock from Earth's mantle was brought to the surface through vertical cracks, creating a layered intrusion.

Key Geological Feature

Layered igneous intrusion, resembling a "layered cake" due to distinct rock strata.

Lobes/Sections

Divided into eastern, western, and northern sections, all formed at the same time.

Ore Deposits

It contains the world's largest reserves of platinum-group metals (PGMs) and platinum group elements (PGEs) — platinum, palladium, osmium, iridium, rhodium and ruthenium — along with vast quantities of iron, tin, chromium, titanium and vanadium.

 It represents about 75 percent of the world's platinum and about 50 percent of the world's palladium resources.

PRACTICE QUESTION

Q.Consider the following statements about the Bushveld Igneous Complex (BIC):

1. It is located in South America and is the largest layered igneous intrusion in the Earth's crust.
2. The BIC contains the world's largest reserves of platinum-group metals (PGMs).
3. The formation of the BIC occurred about 2 billion years ago due to volcanic activity.

Which of the statements given above is/are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 3 only

Answer: b

Explanation:

Statement 1 is incorrect: It is the largest layered igneous intrusion within the Earth's crust. It is located in northern South Africa, exposed at the edge of the Transvaal Basin. It covers a pear-shaped area of over 66,000 sq.km

Statement 2 is correct: The Merensky Reef is a layer of igneous rock in the Bushveld Igneous Complex (BIC) in the North West, Limpopo, Gauteng and Mpumalanga provinces of South Africa which together with an underlying layer, the Upper Group 2 Reef (UG2), contains most of the world's known reserves of platinum group metals (PGMs) or platinum.

Statement 3 is correct: The Bushveld Igneous Complex covers a pear-shaped area in the central Transvaal. It is divided into an eastern and western lobe, with a further northern extension. All three sections of the system were formed around the same time—about 2 billion years ago—and are remarkably similar.