ver. EXP374 March 2018

I. INTRODUCTION

The IODP Core Lab Cookbook is intended to guide Marine Laboratory Specialists (Techs) sailing onboard the R/V JOIDES Resolution in basic core lab procedures. All Techs assigned to the core lab share the responsibility of processing core and maintaining the lab. Below is a drawing of the core lab to help illustrate the procedures described in this Cookbook.

II. SUPPLYING THE LAB

At the beginning of an expedition, the core lab should be fully stocked and stock levels maintained during the cruise. Supplies can be obtained from Upper Tween, Pallet and Hold Reefer stores. Please remember to check out all supplies on the check-out sheets located in each storage area. In the core entry area there is a list of supplies for the core lab and where they are stored. Following is a detailed list of the supplies needed for the each area:

Catwalk Supplies

• clear, blue, and yellow end caps
• acetone in red squirt bottles (with “acetone” label)
• clean, absorbent rags
• wooden meter sticks (~149cm)
• 4" stainless steel spatulas
• permanent red markers (Marks-a-lot)
• chisel and mallet for harder sediment and hard rock
• liner puncture tool or drill for gassy sediments
• hammer, hacksaw, plunger, core catcher tools
• china markers for hard rock and marking liners on wet days
• core liner cutters with good blades
• liner patch
• Nitrile gloves, various sizes (bin by catwalk entry door)
• safety glasses (bin by catwalk entry door)
• hearing protection (bin by catwalk entry door)

These supplies must be clean. Meter sticks should be trimmed slightly short to yield 150 cm core sections. Rusty tools should be cleaned or replaced - a small amount of rust can ruin core material for paleomagnetics.

The chem techs provide their own supplies for taking headspace and vacutainer samples. IW samples require no special supplies. You should work with the Curatorial Specialist to maintain the supply of equipment for any special catwalk sampling such as MBIO.

Description Table Supplies

• glass slides
• toothpicks
• mounting media (Norland Optical Adhesive for ultraviolet curing)
• coverslips
• smear slide cases, smear slide labels
• glass sample vials with snap lids
• miscellaneous glassware
• desk supplies, including pens, pencils, Liquid Paper, rulers, etc.
• gloves for those who do not remove their jewelry
• GLAD™ Plastic Wrap

D-Tube Rack Supplies

• black (working) or red (archive) D-tube end caps
• d-tubes
• black (working) or red (archive) Permanent Markers
• waxed core boxes
• polyethylene tape (d-tube tape)
• core box stapler and staples
• shrink wrap

Sample Table Supplies

            The bins under the sample table should be stocked with:

• 5 and 10 cc sample tubes and scoops
• 5 and10cc foam plugs
• pop top vials
• sample bags
• foam rods
• "Kapak" bags
• ceramic-bladed knives
• P-Mag cubes
• other supplies as labeled

Splitting Room

• hook, utility and core cutter blades
• cleaning sponges
• acetone
• hard rock dividers, halved end caps (blue and clear)
• split foam rods
• PAL spacer foam, both black and red for sediment cores
• permanent red and black markers, china markers
• spatulas, various sizes
• squirt bottle with DI water

III. IODP CORE NAMING

IODP has a specific naming convention for identifying cores, data and samples. All are named with the leg number, site number, hole letter, core number, core type, section number, and which half (working or archive) plus Text ID. Samples and data will also include the sample interval.

Here is an example for scribing core liner in the Laser Engraver or by hand if needed

323-U1243B-6R-5W, ß, SHLF55443322

Here is an example for a sample:

323-U1243B-6R-5W, 25-30 cm, CYL55443322

Core Types

The following is a list of all the valid core types and their associated code with the most commonly used in bold:         

IV. CORE RECOVERY - CATWALK

After the liner is removed from the core barrel, it is placed on the catwalk holders (working side up, denoted by the double-lines on the core liner), where it is temporarily capped at either end to keep sediment from falling out during the initial handling stages. Full core barrels are usually 9.5 meters long, yield six sections, a shorter seventh section, and a core catcher. Recovery of material in length to the cored interval is considered full, or 100% recovery. However, the length of the recovered material may differ from the length of the cored interval. Recovery less than the cored interval may occur for a variety of reasons. Apparent recovery greater than the cored interval may also occur, typically a result of gaseous expansion of the sediment.

Cores taken from a hole are numbered serially from the top of the hole downward. When full recovery is obtained, the core sections are numbered 1 through 7, the last section being shorter than 1.5 meters. For sediments, the core catcher sample is extruded into a short piece of plastic liner and is treated as a separate section below the last core section. For hard rock, material recovered in the core catcher is included at the bottom of the last section.

The Curatorial Specialist and techs measure and mark the ends of each section, labeling each with core, core type and section number and an arrow pointing 'up'. At the section breaks, the liner is cut with a circular cutting tool and cut through the contained sediment with a spatula. If the material is well lithified a hacksaw or hammer & chisel is used to section the core. After separating into sections, whole round (aka catwalk samples, see next section) samples are taken. After the whole round and head space samples are removed from the catwalk, the rest of the core may be capped and glued with acetone. Blue end caps are placed at the top of each section, clear end caps at the bottom, and yellow end caps at the end of any section from which a whole round sample was taken.  Once labeled, sectioned and capped, the core is ready to be brought into the Core Lab for processing.

For obtaining good measurement on the NGR, a section needs to be minimum of 50 cm, preferably more than 50 cm. Curator/ALO should mark the second to last section accordingly to ensure the last section is at least 50 cm. For example – if the last two sections measure 200 cm, it is better to measure the last two as 120 and 80 cm, rather than 150 and 50 cm, or if the last two sections measure 175 cm, it is better to measure the second to last as 100 and the last 75 cm.

V. CATWALK SAMPLING

In addition to the usual hard rock/soft rock sample requests taken from the split core at the sample table, shipboard scientists will most likely take samples on the catwalk. Because most of these analyses are sensitive to the geochemical nature of the material it is important to keep the catwalk area acetone-free until the shipboard scientists and chem techs have finished taking their samples. All samples taken on the catwalk must be recorded in Sample Master.

Paleo Samples (PAL)

(PAL = paleontology) -  Paleontologists receive material from the core catcher for biostratigraphic dating of the core. Generally, 5 cm is sufficient, but in unfossiliferous material a greater volume may be required. This sample typically comes from the bottom of the core catcher.

After the PAL sample is taken, the core catcher is placed in plastic liner, capped and glued with acetone, and labeled with black marker. Leave an empty space in the liner where the PAL sample was removed. A foam spacer will be added after the liner is split. The PAL sample should be recorded as sample code PAL in Sample Master.

Head Space/Gas Analyses (HS, VAC)

The Shipboard Chemist or Chemistry Technician will take at least one 5cc sample for analysis of hydrocarbon composition and concentration. These include a sediment sample for headspace gas analysis (HS) and, if present, free gas samples (VAC or Vacutainer Samples). These samples are immediately analyzed to determine if it is safe to continue drilling.

Headspace samples are taken from the top or bottom of a freshly cut section, depending on the condition and lithology of the core, usually adjacent to the IW (interstitial water whole round sample). The cylinder used for headspace sampling removes material from the working side of the core. In the case of lithified sediments, scrapings or chips are taken. These samples are entered in Sample Master as sample code HS.

When gassy voids are present, the chemist may need to take free gas samples using a puncture tool and a vacutainer. Shipboard scientists may take as many vacutainer gas samples as desired for immediate or later analysis. The location of each sample must be entered in Sample Master as sample code VAC.

Interstitial Water Samples (IW)

Interstitial waters for geochemical analysis samples are generated from the whole round samples removed on the catwalk. In less consolidated sediments at the top of a borehole, IW samples are generally 5cm long (176cc). The size of the sample may be increased as the sediment becomes more lithified with depth. The Co-Chief Scientists, Staff Scientist, and Curatorial Specialist work together to come up with an IW sampling plan that best meets the needs of the shipboard party. These samples are entered in Sample Master as sample code IW.

When core recovery is less than about two sections, whole round sampling is often suspended. However, there is no official policy limiting the amount of whole-round sampling when recovery is low. The unofficial policy is that the co-chiefs, staff scientist, and the Curatorial Specialist define appropriate limits on whole round sampling to safeguard the scientific interests of the cruise. Always get the Curatorial Specialist’s (or his/her representative’s) OK to cut IW samples.

VI. IN THE LAB

The Curatorial Specialist or ALOs then enter the pertinent data into Sample Master to generate the bar coded labels for each section.

The marine technicians engrave the working (double line) and archive (single line) side of the liners with the Laser Engraver. Standard IODP identifier, "EXP-SITE-HOLE-CORE-CORETYPE-SECTION and TEXT ID" (e.g. 323-U1340A-1H-1W, ß, SHLF55443322). This ensures that each section is permanently and uniquely distinguished. The Laser Engraver is generally used to engrave the cores, however if the Laser Engraver does fail the sections must be labeled with the dremel tool.  View the Laser Safety training presentation that can be obtained from the ALO’s before using the Laser Engraver and read the user guide for Laser Katjie program. If engraving by hand (using Dremel™ tool) the engraving should be as legible as possible. The blue end caps of each section should be marked with the core, core type and section number like so: