In pics: Gabbros under electron microscope (6)

The structure of Gabbro under electron microscope aboard the JOIDES Resolution is pictured by Zhang Jiansong on Dec. 26, 2015. (Photo/Xinhua)

On Dec. 26, 2015, some 30 scientists from 12 countries, including China set out on an exploration mission to the southwest Indian Ocean aboard the JOIDES Resolution, as part of the International Ocean Discovery Program (IODP). The IODP is the world's largest geo-science research program with 26 countries in its membership, according to Xinhua News Agency.

Scientists will puncture through the Earth's crust and into the mantle below for the first time to take rock samples. So far, they have collected samples of gabbro from nearly 300 meters beneath the seabed.

Gabbro is a rock of coarse-grained magmatic crystalline structure, mainly composed of clinopyroxene and plagioclase composition, and might also contains hornblende, olivine and other ingredients. Gabbro rock is one of the representatives of the deep ocean crust.