Online Books On Carbonate Geology

Wiley Interscience maintains quite an extensive archive of online geology books. I've bookmarked a couple of their journals and usually go over to browse through the latest issue of Basin Research and decided to explore the site further. 

There's lots to catch the attention of sedimentary geologists.  Here is a list of online books available on carbonates:

Calcretes 

Carbonate Cementation in Sandstones 

Carbonate Diagenesis

Carbonate Mud-Mounds 

Carbonate Platforms

There is plenty for clastic sedimentary geologists too and other books on related topics of sedimentation and tectonics. 

This one caught my eye: PreCambrian Sedimentary Environments

I first developed an interest in carbonate sedimentology during a graduate mapping project in the Proterozoic Cuddapah basin of south India.  It was a sequence of stromatolite dolostones, limestones and quartz arenites exposed mostly along the south dipping limbs of an anticline. 

You can see the dip slopes in the image below.

The hard part of working on Proterozoic carbonates was that most books and atlases on sedimentary lab training use fossiliferous Phanerozoic carbonates as examples for descriptions of carbonate textures and grains and fabrics. And the Proterozoic textures I was looking at were to me at first ...as clear as mud.

I mean that literally. All I saw in those rocks was carbonate mud.

What strikes you about Proterozoic carbonates when you have looked at a lot of them is the overall rarity of sand facies. That's due to the absence of metazoans which started contributing skeletal particles and fecal pellets begining Phanerozoic times. Ooids and intraclasts do occur but they are spatially restricted. But there are lots of weird and wonderful fabrics and cements in these rocks. PreCambrian carbonate platforms were dominated by microbial communities and chemical precipitates and these do form environment diagnostic associations,  just like Phanerozoic facies.

It took getting used to but I was hooked. I do wish though that someone would create a lab handbook which documents Proterozoic carbonate microfabrics and microfacies (would be a great post series too). That would make a most helpful reference manual for carbonate sedimentologists.

Oh.. all these books are pay access...but it really is a bonanza if you have a subscription through your University or otherwise.

Epistemology Of Speciation

I am always on the lookout for better ways to express the evidence for evolution.  One common doubt is that we have never actually  observed one species giving rise to a new species, so how do we know that speciation occurs in nature? 

I liked this view by Steve Mirsky from his recent article in Scientific American on Are Dog Breeds Actually Different Species?

The claim makes me think of the trial where a man was charged with biting off another man’s ear in a bar fight. (Incredibly, Mike Tyson was not involved.) An eyewitness to the fracas took the stand. The defense attorney asked, “Did you actually see with your own eyes my client bite off the ear in question?” The witness said, “No.” The attorney pounced: “So how can you be so sure that the defendant actually bit off the ear?” To which the witness replied, “I saw him spit it out.” We have the fossils, the intermediate forms, the comparative anatomy, the genomic homologies—we’ve seen what evolution spits out.

Funny and definately quotable. 

Tip: WEIT

Sandman Michael Welland On Radio

Michael Welland who writes the fascinating blog Through The Sandglass was on New England Public Radio Station WICN for an interview: Inquiry with Mark Lynch. 

Philosopy, engineering, quicksand and beaches made up of parrotfish poo! All packed in an entertaining 28 minutes.

Go Listen!

Great talk Michael!

Geology Search Using Wolfram Alpha

The much hyped engine is here.

Is Wolfram Alpha a search engine?

No. It's a computational knowledge engine: it generates output by doing computations from its own internal knowledge base, instead of searching the web and returning links.

Input: Calcite Aragonite Dolomite

Results: Wolfram Alpha

You can compare any mineral this way and get a table of properties. A similar search using rock names for example basalt granite gabbro brings up a table with the thermal and mechanical properties. Not all rock types yield a satisfactory answer. I tried to compare sandstone and limestone and there was partial data only for chalk. Queries like olivine solidus or melting temperature granite got no results.

You can do computation with the quantitative attributes.

tensile strength basalt / granite

density coesite /quartz

That is the aim of Wolfram Alpha- to make it possible to compute anything that is computable.

Queries like earthquakes yields a lot of info. You can get a translation of the Richter scale in energy equivalents and earthquake information for any country like the one I tried for India below.


Results: Wolfram Alpha

There were some surprises. I queried dinosaurs and apparently their database has enough information to compare weights of different dinosaur species. Want to know whether Brontosaurus or T. Rex was heavier. Just provide the species name!

Don't try to use this as a geology term dictionary. You will come up empty for most types of inputs. It's not meant to be that kind of reference.

There were humorous moments:


Results: Wolfram Alpha

No geological time information? There is but you have to put in a numerical input:


Results: Wolfram Alpha

It works best with pieces of information that have quantitative attributes to it. For more general knowledge and descriptive queries you will have to stick to Google or whichever other web source you prefer.

W Alpha is still in Beta according to the makers and always will be.

It was fun. Try it out. I don't anticipate using it a whole lot, at least not as much as a regular search engine.

Economist has a article on it and CNET has a bunch of reviews.

Specially For Dog Lovers

Just a quick pointer to a really interesting talk on the modern dog and recent work on the genetics, dog diseases and evolution of man's best friend.

Go to NPR Science Friday to listen or download the podcast.

There is a link to an earlier talk on evolution of dogs which is also worth listening to. Genetic and fossil data suggest domestication of dogs began as early as 15,000 to 20,000 years ago.

Here's an intriguing question. Humans have controlled the evolution of dogs, but did the inclusion of dogs in the Pleistocene human social milieu influence human evolution? Nicholas Wade in his book Before the Dawn has suggested that dogs may have helped humans make the transition from foraging to settled societies. People who settle down in one place risk being attacked and dogs who attach themselves to a owner would have been sentries keeping guard.

Did that also reduce violence in general, make us less aggressive? Human skeletal morphology has changed a bit in the last 20,000 years or so. We have more gracile features - smaller and thinner skulls, smaller teeth than earlier humans. Some experts like primatologist Richard Wrangham believes that this gracilization could have occurred if aggression was less beneficial and evolution favored pedomorphic changes i.e. retention of juvenile features in adulthood. Adult aggressive traits would have then diminished over time.

Maybe dogs had something to do with this? If we outsourced violence or prevented it because of their presence.