A recent pillow lava flow with biological material resting between the pillows, indicating where low-temperature hydrothermal fluid has been leaking out of the crust.

Hydrothermal mineral laden fluids give a smoky appearance to the waters near a hydrothermal vent.

Large pillow lavas on the Galapagos Rift

Looking down a cliff-face into a deep fissure along the Galapagos Rift.

A large crack in an otherwise smooth lava sea floor along the Galapagos Rift

Note the white faces on the rock in the right center of the image. This apparently once continuous tube-like lava flow appears to have been pulled apart as this rift formed. Ocular proof of plate tectonics in action. A mini-version of the fit between Africa and South America.

Pillow lavas with light sediment cover. Two red shrimp are seen in the left half of the image.

Cracked pillow lavas with hydrothermal alteration of the rock faces. Two red shrimp appear to be acting in concert in lower center of image.

Diffuse venting areas, such as this one found on an early dive, host unique microbial communities fueled by nutrients contained in the escaping hydrothermal fluids.

Diffuse venting areas, such as this one found on an early dive, host unique microbial communities fueled by nutrients contained in the escaping hydrothermal fluids.

Diffuse venting areas, such as this one found on an early dive, host unique microbial communities fueled by nutrients contained in the escaping hydrothermal fluids.

A recent lava flow showing white microbial staining on the broken basaltic rocks , caused by discharge of warm hydrothermal fluids through the seafloor. The discharge is still occurring at this location as evidenced by the shimmering aspect of the waters over the white bacterial covered area.

Hydrothermal mineral laden fluids give a smoky appearance to the waters near a hydrothermal vent. The sea floor can barely be perceived below with a white vent crab seen in lower center of image and white microbial covered pillow lava structures seen as well.

Classic pillow lavas in foreground with hydrothermally altered material in background.

Hydrothermally altered and shattered pillow lavas. A large red shrimp is in center of one shattered pillow structure.

A deep crevasse probably marking proximity to the locus of seafloor spreading.

An extinct hydrothermal spire probably composed of sulfide minerals spewed from a black smoker.

Closeup of the surface of an extinct hydrothermal spire probably composed of various sulfide minerals. Note white brittle star on this spire, a type of fauna hardly ever noted in proximity to active venting.

Pillow lavas at the edge of crevasse near the locus of active spreading.

An oddly broken lava slab showing cooling zones of lava and pink and white alteration.

A recent pillow lava flow with biological material resting between the pillows, indicating where low-temperature hydrothermal fluid has been leaking out of the crust.

A field of extinct sulfide chimneys, several meters high, rise above the surrounding seafloor. The pink staining is a combination of biological and chemical processes.

A field of extinct sulfide chimneys, several meters high, rise above the surrounding seafloor. The pink staining is a combination of biological and chemical processes.

A field of extinct sulfide chimneys, several meters high, rise above the surrounding seafloor. The pink staining is a combination of biological and chemical processes.

A field of extinct sulfide chimneys, several meters high, rise above the surrounding seafloor. The pink staining is a combination of biological and chemical processes.

A field of extinct sulfide chimneys, several meters high, rise above the surrounding seafloor. The pink staining is a combination of biological and chemical processes.

Apex of extinct sulfide chimney, several meters high, rises above the surrounding seafloor. The coloration is a combination of biological and chemical processes.

Inactive sulfide chimneys along the pinnacle of one tall extinct sulfide spire. It is likely that these once had billows of superheated hydrothermal fluid emanating from them. They form when minerals in the hot fluid precipitate out upon contact with seawater.

Inactive sulfide chimneys along the pinnacle of one tall extinct sulfide spire. It is likely that these once had billows of superheated hydrothermal fluid emanating from them. They form when minerals in the hot fluid precipitate out upon contact with seawater.

Inactive sulfide chimneys along the pinnacle of one tall extinct sulfide spire. It is likely that these once had billows of superheated hydrothermal fluid emanating from them. They form when minerals in the hot fluid precipitate out upon contact with seawater. This is the summit of a 10+ meter high extinct chimney.

Rugged lava cliff face with small tube worms and white holothurian

Microscopic microbial material often lines cracks and vent openings in the basaltic seafloor lava following volcanic eruptions.

Microscopic microbial material often lines cracks and vent openings in the basaltic seafloor lava following volcanic eruptions.

Bacterial mat covering basaltic rocks and white vent crabs

Vent shrimp and crabs on rock covered with microbial material

Vent shrimp on gray rock surface

Smooth fairly new black shiny lava overlying angular lava boulder field.

Small anemones and small tube worms on rock race

Pillow lavas overlying angular rock face in relatively biota poor area

Lone lava boulder lying on ridge of angular volcanic rock.

Dead broken clam shells indicating an area of previous hydrothermal venting.

An open lava tube. This collapsed feature often occurs when the outer edges of a flow are quickly cooled by contact with seawater. The insulated lava inside remains viscous and eventually recedes, creating a void.

Antipatharian sea whip coral colonizing area of large pillow lava formations. Red shrimp seen to left of base of coral.

Hydrothermal 'smoke", really mineral-laden vent fluids, rising into water column at Tempus Fugit vent field.

In a hydrothermal venting fog cloud with much particulate matter raining down.

A Brachyuran crab rests on rock near a site of diffused venting. These blind crabs are typically found inhabiting mussel beds close to hydrothermal venting.

Microscopic microbial material often lines cracks and vent openings in the basaltic seafloor lava following volcanic eruptions. This area has a particularly interesting pattern of microbial coverage.

Shrimp and crabs colonizing a rock outcrop at a diffuse venting site.

Brachyuran crabs rest on rock near a site of diffused venting. These blind crabs are typically found inhabiting mussel beds close to hydrothermal venting.

Brachyuran crabs are seen on a rock surface near a site of diffused venting. These blind crabs are typically found inhabiting mussel beds close to hydrothermal venting.