Bharath, Golden Heaven - the Core of Earth

Excerpts from Lord Macaulay's address to the British parliament on 2 February, 1835

"I have travelled across the length and breadth of India and I have not seen one person who is a beggar, who is a thief. Such wealth I have seen in this country, such high moral values, people of such calibre, that I do not think we would ever conquer this country, unless we break the very backbone of this nation, which is her spiritual and cultural heritage, and, therefore, I propose that we replace her old and ancient education system, her culture, for if the Indians think that all that is foreign and English is good and greater than their own, they will lose their self-esteem, their native culture and they will become what we want them, a truly dominated nation."

                       

09.01.2006 <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
Earth's Inner Fort Knox
Searching for a pot of gold? Try the center of the Earth.

by Anne Wootton

http://discovermagazine.com/2006/sep/innerfortknox

More than 99 percent of Earth's gold is missing—it all sank tothe center of the planet billions of years ago. In fact, says geologist Bernard Wood of Macquarie University in Australia, there's enough gold in Earth's core to coat its surface in 1.5 feet of the stuff. How did it get there?Earth formed from a series of smaller planetesimals that crashed together over the course of 30 million to 40 million years. Wood deduced how much gold ought to be present in Earth's crust by comparing the crust's composition to that of meteorites similar to the planetesimals. He concluded that the crust was depleted of gold, platinum, and nickel and suggests that all these iron-loving elements were pulled into Earth's iron-rich core while its surface was still an ocean of molten magma.In fact, if meteorites hadn't later deposited gold on Earth's surface millions of years after its core had fully formed and its crust had cooled, gold would be even more rare and expensive than it is today. Wood has calculated that 1.6 quadrillion tons of gold must lie in Earth's core. This may sound like a lot, but it is really only a tiny percentage of the core's overall mass—about one part per million. The core holds six times as much platinum, Wood notes, "but people get less excited about that than gold." Last Update: Thursday, June 15, 2006. 11:27pm (AEST)
Researcher calculates gold within Earth's coreBy Stephen Pincock for Science Online

An Australian researcher says there is enough gold buried deep within the Earth's core to cover the entire land surface of the planet to a depth of half a metre.

Macquarie University geologist Professor Bernard Wood made his calculations based on research published in today's issue of journal Nature.

Professor Wood and his colleagues have charted the early history of Earth's development, starting with the birth of the solar system more than 4.5 billion years ago and focusing on the formation of Earth's molten metal core.

"By looking at other stars that are currently at the state our sun was in then, we can see that they are surrounded by a flattened disc of dust and gas," Professor Wood said.

"We know that within about 10,000 years, these formed into small bodies that were about 10 kilometres across."

Radioactive dating has shown that over the next 100,000 to one million years, those small "planetesimals" collided to form planetary embryos of a size between that of Mars and the moon.

Within 10 million to 100 million years, larger planets had formed.

"In the case of Earth, it was around 30 million years," Professor Wood said.

'Magma ocean'

Professor Wood says the Earth was probably covered in a sea of molten rock, hundreds of kilometres deep, early in its history.

He says this "magma ocean" reacted with metals during the planet's development, extracting many of the most important and interesting elements, including gold, and eventually depositing them in the Earth's own iron-rich core.

To calculate how much gold was in the Earth's core, Professor Wood compared the composition of the Earth's crust with that of meteorites, which can be used to represent planetesimals.

He and other researchers have found that the meteorites had similar levels of all elements that would not normally dissolve in iron.

But they also noted that meteorites had higher levels of elements such as gold, platinum and nickel.

"This tells us that the Earth is chemically very similar to those meteorites but the Earth's crust is depleted in all those elements that like to dissolve in iron," Professor Wood said.

He says there is only one place those elements can have gone - the molten core.

"We can say that more than 99 per cent of the Earth's gold is in the core," he said.

"It's a nice image to think we could all step outside and be knee-deep in the stuff."