A bit of paleo for the enthusiasts. Nearly forty years ago, a Mexican fisherman named Rudesindo Cantarell noticed his shrimp nets kept on getting coated with sludge in Campeche Bay, off the Yucatan Peninsula. Turns out crude oil was bubbling up offshore. Today, the Cantarell oil fields are the second-largest producing in the world... and in rapid decline, but that's another story.
The fields themselves are carbonate breccia -- pieces of rubbly limestone embedded in a natural cement -- several hundred feet thick, sealed by dolomite, a tougher chemical relative of limestone. Their formation dates from the Cretaceous-Tertiary boundary. When the dinosaurs became extinct.
You got it: the dinosaur killer meteor impact at Chicxulub made Cantarell. To quote Grajales-Nishimura et al.:
On the basis of the unique stratigraphy and distribution of impact material within the calcareous breccia, the following sequence of events and products can be visualized as having taken place within few minutes or hours after the time of the impact: (1) carbonate platform collapse due to shaking, resulting in deposition of the lower breccia; (2) arrival of ballistic impact ejecta (ejecta layers with impact minerals); and (3) reworking and mixing of the ejecta layer with coarser material by one or more passages of the impact-generated tsunamis that were reflected back and forth across the Gulf of Mexico paleogeography.65 million BC, a real bad year to go to Cancún.
Reference: Grajales-Nishimura et al., "Chicxulub impact: The origin of reservoir and seal facies in the southeastern Mexico oil fields", Geology; April 2000; v. 28; no. 4; p. 307–310.
Actually, I knew that one. I'm still waiting for the paleo biochem post you promised way back when.
I need to finish up the posts that I had planned for the Permian Extinction. The ecology, what-if it never happened, and such posts. Just need time. Then I need to start moving on to the Late Triassic (which there's not a lot of info on, but a bit).
I might be contributing some to the Permian paleosims in the near future as well as some code that might get folded back into the CCSM model. I *AM* gonna end up pissing off that researcher that I did already. He's got quite a rep already it seems.
Permian Hurricanes are gonna be fun. ;)
Posted by: Will Baird | April 26, 2007 at 01:49 PM
Will,
Permian Hurricanes are gonna be fun.
Why?
Posted by: Bernard Guerrero | April 27, 2007 at 05:03 AM
re Permian Hurricanes fun factor
Why?
I'm putting together the project plan to simulate the world at the End Times of the Permian for a few repeats of a simulated year. I'd like to do about ten runs. We'd start with a small scale to just do the code changes. Then scale up to centerwide: I think I can integrate multiple couplers so that all the different machines can run CCSM sims and still be a part of the greater whole. If it works very well, and that's a big if, then we might scale it up to see what the limits are and perhaps take a shot at the Gordon Bell Prize. That's the computer side of the whole thing.
The science side, well, I have a working hypothesis that the Permian weather actually was a killer. It probably made things a lot worse. My suspicion is that if you replicated many of the conditions of the PTE here and now, but left our weather intact (fallacy, I know, but hear me out), you wouldn't get the devastation of the PTE. Here's a way to test that.
Posted by: Will Baird | April 27, 2007 at 10:33 AM
Carlos, any historical tidbits on Bohai Bay? Inquiring minds want to know!
Posted by: Bernard Guerrero | May 05, 2007 at 02:12 PM
Sure. Take a look at a map. See how the Shandong peninsula is matched by Korea Bay, and the Liaodong peninsula by Laizhou Bay? How it's sort of rectilinear? It's not a coincidence.
Picture lines running along the sides of Shandong and Liaodong. In the way that parts of California are sliding along the San Andreas fault, so too are those chunks of Korea, China, and the seafloor in between.
But also notice how well one side of the Bohai Sea -- I think that might be redundant, like the La Brea tar pits, but never mind -- mirrors the other. Several things going on here, which probably means a rather complicated subsurface geology. (The industry word is 'challenging'.)
Posted by: Carlos | May 06, 2007 at 05:08 AM