Cyanobacteria and Oxygen. Stromatolites are created by cyanobacteria, also called blue-green algae. These microscopic life forms are not really algae at all but bacteria that have the ability to carry out photosynthesis.It is the process of photosynthesis combined with the growth of the cyanobacteria that creates the distinctive dome-shaped, finely layered rocks we call stromatolites.his was transformed because cyanobacteria could photosynthesize to make its food. The process of photosynthesis uses carbon dioxide and produces oxygen as a byproduct. Billions of cyanobacteria producing oxygen, constantly, over many millions of years made an atmosphere that could support life as we know it.
Sequence Boundary. The sequence boundary is an unconformity updip and a correlative conformity downdip. Where it is an unconformity, it is a surface of subaerial exposure and erosion; however, the expression of those features in an individual outcrop may or may not be obvious.he transgressive surface represents the first major flooding surface to follow the sequence boundary and is usually distinct from the relatively minor flooding surfaces that separate parasequences in the lowstand systems tract.
Divergent Margins. boundaries where plates are moving toward each other, and. sometimes one plate sinks (is subducted) beneath another. The. location where the sinking of a plate occurs is called a subduction. zone. A transform boundary is where plates slide past each other. with no creation or destruction of lithosphere. Plate Margin Examples. There are three general types of plate boundaries: divergent, convergent, and transform. Each general type has multiple. âspeciesâ: divergent boundaries can be spreading ocean ridges or. continental rift zones; convergent boundaries can occur between. two continental plates.