Monday, January 28, 2008

Dude, what happened to Cenozoic stratigraphy when I wasn't looking?

There's all this discussion going on about the existence (or not) of the Quaternary Period, and whether we ought to declare a new epoch called the Anthropocene. Now, it's pretty scary, realizing that humans have had geologic-scale effects, especially on climate. But I've heard talk about the Anthropocene already. (Elizabeth Kolbert discusses it in her excellent book Field Notes From a Catastrophe.)

But I was shocked by another, much more mundane comment:

In recent decades, ICS--with the consent of the International Union of Geological Sciences (IUGS), the world's ruling body on such matters--dropped the Tertiary as well. (From the Science article about the Quaternary.)

Now, I've never worked on Cenozoic rocks. (Mesozoic, Paleozoic, and Precambrian, yeah, but never young stuff.) But my house is sitting on rocks that are mapped, even in very recent maps, as Tertiary. I live in a state where "Tertiary volcanics" is as common a phrase as "Quaternary alluvium." And, probably most embarrassingly, I've made students memorize a geologic time scale that included the Tertiary. (Not recently; my current institution has an excellent Historical Geology class, and I let the sed/strat/paleo guy deal with the time scale.)

I understand that stratigraphers have good reasons for wanting names that make sense, and for wanting worldwide correlations to be possible. But I like my Tertiary volcanics. And the K-T boundary.

Of course, I still haven't gotten over the change from "sphene" to "titanite"...


Jessica Ball said...

Dropped the Tertiary??

At risk of sounding sophomoric, WTF?! Does this mean I have to back to my thesis and fix all the dozens of times I used "Tertiary volcanics"?

Wait, when did they change sphene to titanite? I only took mineralogy three years ago! Why do I feel old?

Ron Schott said...

Long Live Sphene!!!

Kim said...

I know "sphene" officially became "titanite" in the early 90's, because at least one member of my dissertation committee would correct me about it.

And I guess I had seen "Neogene" and "Paleogene" on geologic time scales. But I don't know anyone who uses the terms - everyone that I know still uses "Quaternary" and "Tertiary." (They don't correspond, either - the Neogene includes the Miocene, Paleocene, Pleistocene, and Holocene. Now I'm curious exactly what major fossil change happened between the Oligocene and Miocene, to make the stratigraphers decide to make that the major boundary.)

My subdiscipline doesn't have any organized body to keep terminology in line, much to the dismay of people who rant about the "strain ellipse" being a "stretch ellipse."

Andrew Alden, Oakland Geology blog said...

Dude, it happened back when we still lived in the Holocene, dude. You're just like the Quaternarists, who got caught napping.

BrianR said...

I have no time at the moment to read the article and evaluate the arguments ... but, dropping the term Tertiary sounds idiotic.

In California we use the terms Paleogene and Neogene quite a bit ... but why should that get rid of Tertiary?

I guess I should read the article before I react, but...oh well.

I bet it's some ego-maniacs way to get attention ... "hey look at me, over here! I'm the one who got rid of 'Tertiary'...I'm awesome. I'm provocative. Look at me!"

John Fleck said...

Nice to see that even in high-falutin fields like geology language remains cheerfully ignorant of attempts by committees to control its destiny. As a practical matter, I'd never put the word "Tertiary" in the newspaper, but I will continue to use it proudly when I'm trying to impress scientists that I know their lingo.

Jessica Ball said...

I've just realized that this is going to completely screw up the mnemonic I learned for the periods on the geologic timescale. Curse you IUGS!

Has anyone got a good mnemonic for COSDCPTJCPN? Or COSDMPPTJCPN (for anyone who uses Mississippian and Pennsylvanian instead of Carboniferous)?

C W Magee said...

Re: the Anthropocene:
There was an excellent slapdown of this idea in EOS about two years ago by Broecker and Stocker:

There may be some Anthropocentenites hiding in the error bars of the isotope data, but I read it as a brilliant refutation.

As for the geologic time scale, changing "Told Jesus Christ To Quit" to "Told Jesus Christ, "Please, No Quiche" works fine. I collect mnemonics here:

Kim said...

The evolution of science terms can be pretty interesting - old terms stick around and get redefined a lot, and although precise definitions are important for allowing us to communicate, well... if the definitions don't fit the needs of the community, the words won't get used. Or they won't get used in the correct way.

Tertiary and Quaternary do get at something important about the science. There is something about the Quaternary - studying it requires a different set of techniques and skills, on continents, at least. It's the realm of geomorphology, and all kinds of different dating techniques, and of soils and climate change. So I think it would be valuable for the stratigraphers to accept its use.

Callan Bentley said...

About time, that's what I say.

"Tertiary" means "third." It refers to Abraham Gottlob Werner's archaic geologic timescale which consisted of:

Primary (first)
Secondary (second)
Tertiary (third)
Quaternary (fourth)

My only question isn't why the Tertiary is dead (I mean, are we mourning the horse & buggy?), it's why we still use Quaternary.

Anonymous said...

What would we call "Quaternary geologists" if we didn't have the Quaternary?

There are "Tertiary volcanics" all over the states of Nevada and California. I haven't heard any field geologists calling them "Paleogene" or "Neogene" any time in my Recent memory.

Thermochronic said...

I'd like to echo Ron's call for bringing back sphene, I am insistent about that, like ordering medium at Starbucks instead of grande or whatever the hell it is.

Seriously though, why should someone so noble as a thermochronologist submit to the nomenclatural whims of stratigraphers? Next thing they'll tell me I can't use eugeosyncline, or refer to granites as acid rocks.

Do you think the Tertiary feels bad, like a recently dumped boyfriend? Perhaps we should send a card.

Elli said...

my master's advisor was one of the crowd who would never call "sphene" "titanite"--and we weren't allowed to either! i now just list it on the mineral sheet as Titanite (sphene)...

the 2004 historical book on my desk states that the use of tertiary & quaternary is "traditional"