1.   At the beginning of each belt was a mid-ocean ridge, where new ocean crust was made.

2.   Judging from the minerals present in the mass of water, it appeared to have spurted out of the ocean crust.

3.   Like a bulldozer, it plowed rock off the ocean crust that was descending and piled it into hills along its edge.

4.   Somehow these shallow reservoirs must provide the stuff that makes new ocean crust.

5.   The cold, bottom water that percolates down into the cracks in the ocean crust carries its own complement of chemicals.

6.   These might consist of old ocean crust or material from one of the boundary layers.

7.   Where the ocean crust is young, lava flows dominate the landscape.

8.   The find, near the Mid-Atlantic Ridge, which cuts a jagged line through the ocean crust, created immediate excitement among oceanographers.

9.   These volcanic rifts gird the globe like seams on a baseball, making ocean crust and, over the eons, moving the continents around like putty.