Palaeo jargon

Every field has jargon — it’s useful (even essential) to have a word or phrase that means something very specific when you’re communicating with someone else who also knows the jargon. But if you don’t, it’s often impenetrable and confusing, and that’s before you take into account that some jargon isn’t referred to the same way in formal writing like a paper or textbook and in informal emails or meetings.

Here I’ve tried to explain some of the jargon in the palaeo world, especially if it’s often used differently in conversation.

Palaeo

First of all, what is ‘palaeo’? Also known as paleo (no ‘a’) in American English, you won’t get very far googling it, unless you actually are after a lot of diet influencers.

Palaeo is short for palaeoclimate, palaeoceanography, palaeobiology, palaeolimnology, and many others besides. The palaeo— part just comes from the Greek for ‘ancient’, so we get the study of ancient climate, oceans, biology, and lakes, respectively. At different universities, these sub-disciplines may be all together in an Earth Sciences department or shared with Geography.

The benthic record (or stack) and LR04

The stable oxygen isotope signature of the calcite shells of benthic foraminifera can be used as a proxy for the combined effects of bottom water temperature and global ice volume. Lorraine Lisiecki and Maureen Raymo compiled this data from the Plio-Pleistocene sections of 57 globally distributed sites and ‘stacked’ the data to get one global average signal (Lisiecki and Raymo, 2005). This stack was given the name LR04 after the authors’ initials and the year they wrote up their findings.
See also: δ¹⁸O, Permille.

Coring vs drilling

Both coring and drilling involve digging into the seafloor in one way or another, but there is a difference. Coring means retrieving a cylinder of sediment or rock from a hole in the seabed. Drilling means using a rotating drill bit to cut through rock. If there’s a gap in the middle of the drill bit then a core of undisturbed rock will be left behind which you can retrieve — so you’ve cored through that interval. If the drill bit is solid, all the rock at the bottom of the hole will get chipped away. Drilling (i.e., with a solid drill bit) is usually faster, but you don’t get the core to study.

For soft sediments, you can core without drilling, by various methods which largely boil down to dropping a pipe into the mud and pulling it out again while holding the mud inside.

So you can drill without coring, you can core without drilling (but only in soft sediments), and you can drill and core (but only in hard rocks). Coring can be carried out from a wide range of platforms, but in academic marine geology, the IODP has been the only programme capable of drilling (coring hard rocks). New advances with remotely controlled seabed drills are changing that, though.

Delta 18 O (or delta O 18)

This one has a lot of variation in both informal writing and speaking. Also known as d18O, delta-eighteen-oh, delta-oh-eighteen, or even just ‘oxygen isotopes’, it is properly δ¹⁸O. The short notation for the stable isotope oxygen-18 is ¹⁸O, and the δ means this is a specific ratio of that isotope with oxygen-16. The value is reported in permille.
See also: benthic record.

Dinos

Dinoflagellates (not dinosaurs, sadly): a group of organic-walled (i.e., not made of a mineral like calcium carbonate or opal) algae microfossils.
See also: forams, nannos.

Expedition 397 (or 301, or Leg 100…)

Although there are many research expeditions (also known as cruises) happening every year in the world of (palaeo-) oceanography, in a palaeo research group, if someone refers to Expedition X, they’re probably talking about one of the IODP cruises, often on the JR. The previous programmes, the ODP and DSDP, referred to them as ‘Legs’, but the numbers are consecutive.
See also: Site 625, Coring vs Drilling, Going on a cruise.

Forams

The shortened form of ‘foraminifera’, a very important group of microfossils in palaeoceanography. They are grouped into those that live in the water column (planktic) and those that live on the seafloor (benthic).
See also: benthic record, dinos, nannos.

The JR

The JOIDES Resolution, the best-known drilling ship of an international collaboration of Earth Science funders and institutions called the International Ocean Discovery Program (IODP), and in the past just ODP (Ocean Drilling Program). JOIDES stands for ‘Joint Oceanographic Institutions for Deep Earth Sampling’.
See also: Site 625, Coring vs Drilling.

Nannos

Short for calcareous nannofossils, the remains of coccolithophores — the ‘bearer of coccoliths’, coccoliths being tiny shield-shaped calcium carbonate plates made by the single-celled organism to protect itself. It makes many coccoliths and arranges them in a shell around it; when these shells are preserved perfectly intact in sediment, they’re known as coccospheres. The chalk cliffs of Dover are made almost entirely of an unbelievable number of calcareous nannofossils.
See also: forams, dinos.

Permille (‰)

Parts per thousand. Like percent (%, parts per hundred), but smaller! Also written as permil, per-mil, or sometimes (lazily) as a percent sign with a lowercase ‘o’ after it: %o. Yuck.
See also: δ¹⁸O, stable isotopes.

The shelf

The continental shelf. Likewise, ‘deep marine’ usually means the parts of the ocean which are deeper (further offshore) than the continental shelf.

Site 625 (or 999, U1533, U1385…)

Each site the JR drills at gets a number, and because the IODP sites are so central to palaeoceanography, when someone refers to ‘site X’, they usually mean the IODP site of that number. Sites beginning with a ‘U’ were drilled by the JR since 2009, after a big refit.
See also: Expedition 397, Coring vs Drilling.

Stable isotopes

Although the list of all stable isotopes runs into the hundreds, when someone in palaeoceanography refers to ‘stable isotopes’, they usually specifically mean the ratios of the stable isotopes of either oxygen or carbon (or both).
See also: δ¹⁸O, permille.

Stage 5 (or 11, 31…)

The marine benthic isotope stack has very distinctive peaks and troughs, which correspond to glacial and interglacial (cold and warm) periods — or stages. These Marine Isotope Stages (MIS) have been assigned numbers going back in time, so we are currently in MIS 1, and the last glacial period was MIS 2. Confusingly, the interglacial period before that (the last interglacial) is MIS 5 after MIS 3 was downgraded. In conversation, people will either say ‘MIS 5’ or they’ll often drop the ‘Marine Isotope’ part and leave just ‘Stage 5’.

‘Going on a cruise’

Not a holiday. In fact, a scientific research cruise (or expedition) usually involves 12-hour work days, 7 days a week, for a month or two, without sight of land. They involve either physically demanding work or intense laboratory work (or both) while dealing with the pitching and rolling of the research ship. That said, they do have their highlights: whales and dolphins are the headline act, but spectacular sunsets, a perfect night sky, and stories to tell your grandchildren all feature too. Read about my experiences on my first cruise, to Antarctica, here.