Geoscience Reference
In-Depth Information
Figure 1.7 Hydrothermal activity in the deep sea. (a) The Rose Garden vent on the
Galapagos Rise in 1979. Vestimentiferan tube worms and mussels dominate. Bresiliid
shrimp and archacogastropod limpets walk on them. (b) Bresiliid shrimp at a Mid-Atlantic
Ridge vent. (c) Serpulid polychaetes and a dandelion in the near field at the Rose Garden.
Most of the serpulids are retracted into their tubes, but the tentacles of several are spread for
capturing food particles from the water. (d) Spaghetti worms cover pillow lava at the
periphery of Rose Garden. (e) The huge thicket of vestimentiferan tube worms at the main
vent fissure at Rose Garden in December, 1979. Mussels live among the worms, principally
at the base of the tubes. (f) The population of vestimentiferans has been drastically reduced,
and mussels have proliferated to form a great pile over the fissure opening. (g) The rift
valley on the East Pacific Rise at 9
N in April 1991. A recent lava flow has blanketed the
valley. Wide-scale venting has encouraged bacterial growth, but there are not yet any
animals grazing on the mats. (h) The same general area in December, 1993, a little over two
and a half years later, showing vigorous colonization by vestimentiferans. The bacterial mats
have disappeared.
Source: Reproduced from Ref.
[100]
.
developing bigger, purer, and dislocation-free single crystals. The method has been
widely accepted since 1960s and practically all inorganic species, starting from
native elements to the most complex oxides, silicates, germanates, phosphates, chal-
cogenides, carbonates, and so on, have been obtained by this method. The technique
is being employed on a large scale to prepare piezoelectric, magnetic, optic,
ceramic, and a host of other materials both as single crystals and polycrystalline
materials. In the recent years, several new advantages of the hydrothermal technique
