Logo Universitat Bremen

Core curation

The ESO Curation Container provides the offshore facility for core curation procedures. All ESO personnel (or scientists) assigned to the Core Curation Container share the responsibility of processing core and maintaining the lab according to IODP standards.
Core Curation Container
Certified 20' Offshore Container (Core Curation)

Alex in Container during ACEX
Alex Wülbers, curatorial offshore representative during Exp. 302 (ACEX) in the old Core Curation container.

IODP core naming

IODP has a specific naming convention for identifying cores, data and samples. All are named with the expedition number, site number, hole letter, core number, core type, section number, which half (working or archive). Samples and data will also include the sample interval. Here is an example for a sample:
Core Types
The following is a list of all the valid core types and their associated code with the most commonly used in bold:

A RAB-C
B Bit Sample
C Center Bit Recovery
D Positive Displacement Coring Motor (PDCM)
G Ghost cores, re-drilled intervals
H Advanced Piston Core (APC)
I In-Situ Water Sample
M Miscellaneous
P Pressure Core Barrel (PCB)
R Rotary Core Barrel (RCB)
S Side Wall Sample
W Wash Core Sample
X Extended Core Barrel (XCB)
Z Diamond Coring System (DCS) also ADBC

Half Types
W Work
A Archive
WR Whole Round

Inside the ESO Curation Container, the curator on duty engraves the working (double line) and archive (single line) side of the liners with the standard IODP identifier:
"EXPEDITION-SITE-HOLE-CORE-CORETYPE-SECTION" (e.g. 310-M0005A-1H-1, W) along with an 'up' arrow. This ensures that each section is permanently and uniquely distinguished. The engraving should be as clear as possible.
The blue end caps (top) of each section should be marked with the core, coretype and section number like this:
The Curator enters the pertinent data into the offshore "Drilling Information system" (DIS). ExpeditionDIS generates the bar coded labels for each section. Print four hardcopy print-outs of the Core Tracking Report.

One copy of the report is left in the curator’s box next to the (left ) offshore DIS entry station computer. Other copies of the Core Tracking Report, a useful reference while sampling and boxing cores, are brought to the database officer. Three sets of labels (archive and working) are printed, one for the core liner, one for the d-tube and one for d-tube cap.

Core recovery

Hard rocks

After the liner is removed from the core barrel, it is placed on the core holders (working side up), where it is temporarily capped at either end to keep sediment from falling out during the initial handling stages. Full core barrels are usually about 3.0 meters long, and they yield two 150 cm sections, maybe a shorter second 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, but will be not very probable during this expedition if recovered material consists of massive corals or limestones.

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 3, the last section might be 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.
When sediment recovery is less than 100%, whether or not the recovered material is continuous, the recovered sediment is placed at the top of the cored interval and then 1.5 meter sections are numbered serially, starting with section 1 at the top. Sections are cut starting at the top of the recovered sediment and the last section may be shorter than the normal 1.5 meter length. The definition of section breaks and therefore cutting the core into different core section will be in agreement with the Co-chief scientists in order to avoid splitting at critical horizons. Core catcher samples will be collected, split and labelled, photographed, and the working half handed over for sedimentolgocial and description. If no core-catcher is collected, a sample from the lower end of the section might be taken for offshore sedimentological and geochemical analysis. The detailed core-flow onboard the drillship is shown below.

--------------
For expeditions with special lithologies: it has been noted that it is important to store corals in dry conditions to avoid that fungi and bacteria may develop in coral skeletons, with the strong possibility of alteration of the initial geochemical signals.

IMPORTANT – No acetone handling & use at all, before the pore water (IW) sample has been taken!!!

The Curator measures and marks the ends of each section, labeling each with core, core type and section number and an arrow pointing 'up'. At the section breaks, he cuts the liner with a circular cutting tool and parts the contained sediment with a spatula. If the material is well lithified a hacksaw or hammer and chisel is used to section the core. The core sections will be capped now. Blue end caps are placed at the top of each section, clear end caps at the bottom. Caps can be fixed temporarily with black tape if acetone cannot be used. Once labelled, sectioned and capped, the core is ready to be brought into the ESO Petrophysics Container for core logging.
Whole round samples will be taken (IF approved) after core logging, provided that the logging can be completed in about 20 to 40 minutes. Whole-round samples will be taken on a selected basis (by microbiologist or geochemist) at an interval of approximately one every 2nd core (in maximum!) depending on core recovery. Yellow end caps are placed at the end of any section from which a whole round sample was taken.

 

 

Exp. 310 (Tahiti)
New core on deck during Exp. 310 (Tahiti).
Exp. 313 (New Jersey Shallow Shelf)
Curation of new core sections during Exp. 313.

Core handling

Hard rocks

The liner is placed on the core holders. If hard rock pieces are scattered along the length of the liner, the upper end is raised slightly to shunt the pieces to the lower end to provide a more accurate recovery measurement. The sections are then measured starting at the bottom of the recovered material and working backwards (i.e. toward the top of the core). Be sure to label the sections in the correct order. Measure until you get to the last section (i.e. Section 1). You may find when you get to Section 1, that it will be full of rock or it may only contain small amount of rock. Now it is time to estimate if you will need additional empty liners to give you extra space to “curate” the core. To “curate” a hard rock core is to add dividers between non-contiguous rock pieces. This almost always expands the core. Once all the sections are numbered, measure the recovered rock inside the liner to get your total recovery.

Unlike soft sediment cores, hard rock cores do not always break at 1.5 meters (might also be valid for massive corals or limestones!). They are sectioned at fractures or other natural breaks as close to 1.5 m intervals as possible. Sometimes pieces longer than 1.5 meters are recovered; then it is necessary to break the core at some appropriate point with a hammer and chisel.

Hard rock sections are carried into the core entry area where the recovery (recovery = liner length in offshore DIS) is recorded on paper forms. The recovery is then entered into offshore DIS and the record saved. The true “curated length” will not be correct until the core is fully spaced-out (i.e. curated). Label and engrave an extra liner or two in case you need to transfer some of the curated core. Note: when working with hard rock, it is always helpful to have a full supply of pre-cleaned and pre-split core liners on hand. Carry the core to the splitting room. The Curator or senior tech will split the first uncurated section of core on the core splitter with the wire removed. Starting from the top of the section, mark the bottom with a red wax china marker of every piece which is long enough not to have rolled in the liner.

 

 

Exp. 310 (Tahiti)
Core interval from Exp. 310 (Tahiti).

V. Diekamp @ ECORD/IODP
Example from Exp. 357 (Atlantis Massif)

Core catcher imaging

Setup
  • Assemble the stage on the base plate using the 4 screws and the grommet (underneath the base plate). Tighten the screws in a crossing way. The scale of the stage should show to the front.
  • Assemble the camera support on the left hand side of the stage and tighten with the screw. In front of the camera support fix the camera with the screw so that the objective shows to the middle of the object on the base plate. You can move the camera support horizontally forward or backward through untightening the screw on the left hand side. Pay attention to the position of the camera/objective (must be parallel to the object as much as possible).
  • Turning the crank you can adjust the height of the camera. With the screws in the back you can fix the wanted position. For the core catchers it is recommended to have a position where the red roller remains at 55 cm to 65 cm depending on the length of the core catcher.
  • Fix the lighting, one on each side of the base plate and put the lamps (Osram, 11 Watt) in. (There are 2 Osram 11 Watt reserve lamps)
Illumination / Flash

To test for the right illumination start with the following propositions: gray scale and color scale should be parallel to the core catcher and on the same level.
In the stage box you can find 2 pieces of polystyrene (styrofoam) marked with a black cross. They have approximately the same height as IODP core catchers. If the size should be different, please improvise taking something else (another piece of polystyrene, a book with the same height,…).
The lighting on each side should be parallel the object as you can see in the photo. If the core catcher is at right angle to the lamps a bright red spot light on the gray scale may occur in the photo when using the flash. Angle 1 is ~ 80 ° and angle 2 ~ 25 °.

It is recommended to use the flash because the light of the to lamps may result as two cones of light on the left and on the right hand side in the photo while in the middle is not enough light. You have to figure out the right angle of the lamps depending on the surface of the object (reflecting) and on other illumination sources (window with daylight or artificial or no light). Use the sandwich paper to avoid cones of light. The sandwich paper makes the light diffuse.
  • Depending on the surrounding, try to use the flash not showing directly to the object but for example to a white wall. This could avoid too strong light of the flash in the middle of the photo.
  • When you press the release button of the camera by hand the camera might slightly move. It is only fixed by the screw. Try to fix the camera additionally with for example hook and loop fastener (using double sided adhesive) at the camera support of the stage.
Camera
  • Using the camera insert the rechargeable battery (black) after loading or use the mains-operated adapter (this would avoid changing the batteries once in a while). Put the compact card into the camera. Fix the flash at the camera. Camera, flash and compact card you can find in a box inside the curation van. There as well you can find the grey and colour scales. The flash as well needs batteries. There is a recharger with rechargeable batteries for the flash. Turn the camera on. All test photos were made using the programme “P”. Aperture and exposure time are then completed automatically by the camera. The exposure time was always lower then 1/50 (this time is recommended by the fabric of the lighting to avoid “black stripes” in the photo). Having exposure times like 1/100 or 1/160 no black stripes appeared. Please check this. If black stripes should appear use the programme where you choose the exposure time (see the manual, should be “M”).
  • Turn the flash on (“power”). With the programme “Tll Auto” the flash automatically adapts to the camera. There is a little disk at the flash which you can use (pull it and put in front of the flash) because it is diffusing the light.
  • Most test photos were taken with the zoom of 25 mm, but depending on the size of the core catcher use 18 mm or 34 mm.
  • Press the release button half way. A sound occurs. This means that the camera focussed automatically and found the right exposure time as well as the aperture. Then press the release button completely.
  • While taking a picture you cannot see anything on the screen. Afterwards press the green arrow and you can see the photo. With the four black arrow buttons you can move forward and backward to see all pictures you have taken.
  • The camera is set to make a “raw” and a “jpg” format which allows you afterwards to adjust for example the colour temperature or the white balance with the programme “Olympus Viewer” (CD inside the Olympus camera box) using the raw format. Only jpg format the compact disk has got space for about 800 photos. Using raw and jpg format it only has got space for 85 pictures.
Turn off
  • When the camera is not in use, please take the batteries out off the camera and out off the flash.
  • Please never leave the grey and colour scales in the daylight and please return with the digital camera.
Photo archive

Please save the photos taken of the core catchers as follows on your laptop:

 

 

corecatcher shot2
The core catcher lying in a right angle to the lamps and using the flash, the gray scale shows a bright red spot in the middle as visible in the next picture. Try to avoid this.

Storing cores and samples

  • All the full core sections, the shrink-wrapped core catcher samples, the waxed wholeround samples for physical properties, and some porewater aliquots will be stored in the temperature-controlled container onboard the platform/drillship.
  • Pore water subsamples that need to be kept frozen with -20°C will be stored in the freezer until shipping to Bremen for the Onshore Science Party.
  • Microbiology samples will be further treated, subsampled and stored with different temperatures (-20°C, -80°C) according to the plan provided by the microbiologist.