Structure of the Earth obducted onto the continental crust and preserved as ophiolite sequences. Many rocks now making up Earth's crust formed less than 100 million (1) years ago; however, the oldest known mineral grains are about 4.4 billion (4.4) years old, indicating that Earth has had a solid crust for at least 4.4 billion years. Earth's mantle extends to a depth of 2,890 km, making it the thickest layer of Earth. The mantle is divided into upper and lower mantle. The upper and lower mantle are separated by the transition zone. The lowest part of the mantle next to the core-mantle boundary is
Women and the environment 1980s was an important decade for women in the environment. In 1980 the term 'ecofeminism' was born with two important events taking place. In April, 1980 the conference, "Women and Life on Earth: Ecofeminism in the 1980's" was held in Amherst, MA, the first in a series of conferences on ecofeminism. In November, 1980 the Women's Pentagon Action took place in Washington D.C.. when the group, "Women and Life on Earth" gathered to protest war, militarism, nuclear weapons and the effects on the environment. At its core, ecofeminism recognizes the link between the oppression of women and the oppression of