1. Chemosynthetic Environment
A Fossil Analogy
By Natalie Quintana

2. What are chemosynthetic environments?
Hydrothermal vents
Located at mid-ocean ridges
Discovered in 1977 on the Galapagos Rift, in the Pacific
Cold seeps
located continental margins extending from the coast to abyssal plains

3. How do hydrothermal vents form?
Tectonic plates separate
Hot, melting rock from earth’s mantle rises to the surface, causing lava to erupt onto ocean floor
temperatures exceeding 350C
The lava forms a underwater mountain, sea mount
Chain of these sea mounts forms the mid-ocean ridge
Black smokers appear at hydrothermal vents

4. Black smokers and mid-ocean ridge

5. What about cold seeps?
Discovered in the Florida Escarpments, in the Gulf of Mexico
Occur when cold fluids with high methane concentration seep from a trench and quickly transform organic matter when reacts with high temperature

6. Modern fauna! Hydrothermal vents Cold Seeps Giant tubeworms
Chemoautotrophic bacteria
White clams
mussels
Cold Seeps
Tubeworms
Mussels
Clams
Various shrimp
Chemoautotrophic bacteria (methane & sulfide reducing bacteria)

7. Fossil Record Gastropods represented seep communities for 100my
Fossil mytilids common in Jurassic-Cretaceous seeps in California & Eocene-Oligocene seeps in Washington State
Many modern groups of organisms originate in the later Mesozoic or early Cenozoic
Ancient seep carbonates represent an archive of chemosynthetic processes
Negative carbon isotope
Methane and sulfide reducing bacteria