Sunday, January 31, 2010
So what am I really doing for my project in Computer Methods
I would like to put my efforts into finding anything I can about microbial/stromatolites/thrombolites in the Ordovician period and also try to find information I can about a relationship between sea-level change and these "matters" if possible nationally or internationally.
Subscribe to:
Post Comments (Atom)
The distribution of microbialite can be examined in terms of temporal abundance (change in abundance through geologic time) and spatial abundance (change in abundance across geologic setting per given time). The latter probably takes precedence over the former. What are the major times for microbialite abundance in Earth history?
ReplyDeleteHow abundance are these microbialites?
ReplyDeleteMicrobialite thrive in areas or times where other organisms cannot "prey" on them. So before diversification of organisms occurred, these microbialites thrived and that is mostly in the Proterozoic. They are primitive life forms.
ReplyDeleteI actually found a paper from "Nature" where it says that there is statistical evidence of a resurgence of stromatolites appearing after the Late Ordovician.
http://www.nature.com/nature/journal/v430/n6995/full/nature02654.html
I actually don't have a subscription to this article so I have not read the whole thing.
I read the same thing about stromatolites increasing in abundance after mass extinctions when there are less organisms to prey on them. Spatially, they are abundant in arid and hypersaline environments -- in the modern. Is the cause for this on account of most organisms avoiding these types of environments, hence the bacteria are less likely to be preyed upon, or is it something to do with the chemistry I wonder?
ReplyDelete@rwturner: Your observation is spot on. Both contribute to the abundance of microbialite. Nutrient levels, pH, oxygen levels and hydrodynamic conditions (water energy, background sedimentation rate) all contribute to the appearance and variation in microbialite. To what degree each of these variables influence microbialite structures is a continuing area of research.
ReplyDeleteI would think the Ordovician would be a quite complex time arena for microbials. For example, mid-Ordovician diversification bringing about many predators, I would think that microbials differ much from early to late Ordovican in terms of environment and morphology. It may also be helpful to compare early Ord. microbials to pre-Ord., and likewise late Ord. to post-Ord. microbials.
ReplyDeleteAnother idea on environment and morphology. For example, hypersalinity would reduce predators. But also tidal areas--for example, if a gastropod faces probable dessication during low tide, it is less likely to feed on the microbes. However, the microbials have to change their morphology to deal with tidal flat conditions.
ReplyDelete