Expedition 401 X-Ray Laboratory Technical Report

Summary

Expedition 401  Mediterranean-Atlantic Gateway Exchange began in Amsterdam, Netherlands on December 12th and ended in Naples, Italy on February 9th. We drilled a total of 4 sites for the extent of the expedition recovering sediment. The samples processed in the x-ray lab where as follows:

• XRD samples were taken to be analyzed as bulk samples.

• XRD samples were taken to be analyzed as clay samples, which were then run as three separate analysis:

  • Clay samples, no treatment involved

  • Clay samples, glycolated for 12 hours 

Sample Totals

*Measurement counts at the time the report was due, some measurements will still to be uploaded.

Clay separation procedure for XRD in expedition 401

• Add sample in 50 ml centrifuge tube

• Add 45ml of water, I added DI water but it can be regular water as well (as mentioned by scientist)

• Sonify samples until the sample are all desegregated

• If samples, flocculate, then add sodium hexametaphosphate about a small tablespoon

• Leave for 12 hours, calculate time by measuring height of sample (Stoke's law)

• Empty suspended liquid in another centrifuge tube 

• Then centrifuge 3000 rpm for 60 min

• Mount clay and measure, then glycolate for 12 hrs. and measure

Bruker D4 Endeavor

All of the XRD samples this expedition where run on the Bruker D4 including clays and glycolated samples.

The parameters set for measurement where as follows:

• Bulk (~2hr scan)

  • random mount

  • 4°-70° 

  • Step: 0.02°

  • Scanning speed: 2s/step

• Clay (~1hr scan)

  • oriented mount

  • 4°-40° 

  • Step: 0.02°

  • Scanning speed: 2s/step

Issues

The Bruker had some flow issues towards the end of the dry dock that continued during this expedition. The flow was ~4.45L/min in the beginning of this expedition which is enough flow to keep the x-rays running on the machine. After running some samples regularly the flow started to decrease until it was to low for the x-rays to be on and the security circuit turned off the x-rays because of low water flow. 

Sample handler issues

The Bruker Sample handler got stuck because when unloading a sample it also took the sample tray with it. The handler does and up and down quick movement, but it doesn't initialize. This happened twice in one day the first time I was able to initialize the machine and it continued making measurements, but after it took the sample out it got stuck again. This had one other time during the expedition, but just by restarting the machine the sample handler gained back movement. This time it does not move in X or Y axis, you just get some movement of Z axis. I wasn't able to finish running the samples in the Bruker after this happened since the sample handler won't move positions. You can only readjust the sample handler when the machine is off. The machine also won't initialize so I can't manually measure the samples either. There is a device component not ready sample changer error when trying to initialize the machine. The 10 samples left for measurement were glycolations, and a similar measurement program was made for the AERIS and the remaining samples where measured there. XRD commander is also not able to initialize the machine.

Haskris

The Haskris had some water flow issues that where causing the x-rays to turn off in the Bruker 4 Endeavor. In order to fix these issues we first flushed out the heat exchanger in the catwalk and reinstalled it. The heat exchanger was not that dirty because it had already been replaced during the dry dock. At this time we also cleaned out the filter in the water tank.  We tightened the pressure valve to see if that would increase the flow, and it did. The flow was increased between 4 - 5 L/min and the x-rays where able to turn back on and I continued measuring samples. The water flow issues came back after a week, and we cleaned out the filter gain as well as tightening and untightening the pressure valve to see if that could reset the flow of water. This worked again to increase the flow of water into the Bruker. However, the ET said that if it happened again we would have to replace the pump. 

1/18/2024

The Bruker was having issues with the waterflow again, so we tried to increase and decrease the pressure using the valve, but that didn't fix the issue this time the water flow would not go past 3.4 /min. We decided to replace the Haskris pump and we changed out the water in the tank as well as the filter. After turning on the Haskris again the water flow went up to 4.5 L/min and it has stayed around there with no further water issues. 

EVA Software

The ICDD license was not activated in the EVA software, so at the beginning of the expedition the license was activated. The scientist also wanted to use topaz for analyzing some of the scans, so we installed the mineral database on the core description computer in the core lab.

XRD for clay separation procedure X401

1. Add sample in 50 ml centrifuge tube

2. Add 45ml of water, I added DI water, but it can be regular water 

3. Sonify samples until the samples are all desegregated

4. If samples flocculate, then add sodium hexametaphosphate and mix again

5. leave for 8 hrs., the time the samples are left was calculated by measuring the height of the sample using Stokes's Law and inputting it into a spreadsheet provided by the scientist

6. Empty the suspended liquid in another centrifuge

7. Centrifuge at 3000rpm for 60 minutes, then empty most of the liquid 

8. Mount clay, measure, then glycolated, then measure. 

AERIS

The AERIS was turned off during this expedition, since the Bruker was used to run XRD. I did turn it on weekly to make sure everything was running correctly. It still has the sample arm error when turning it back on, so I just pushed the arm in and restarted the instrument and that cleared the error. 

Beadmaker

Beadmaker pump

In the process of finding the exhaust for petrol in the thin section lab we realized that the pump for the beadmaker was installed reversed, so it wasn't doing anything (Figure 1).  The pump was then disconnected electronically and bypassed. Now the beadmaker is connected to the "T" that is always on and sucking air out (Figure 3). The exhaust power in thin section overhead cable needs to stay disconnected because the pump is not connected (Figure 2). 

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