Notice from the Reston Groundwater Dating Laboratory
November 17, 2015
This information is applicable to internal USGS projects only. The tritium/helium-3 noble gas contract is not for use outside of The USGS.
Effective November 1, 2015, a new contract for tritium/helium-3 dating and noble gas analysis was issued by the USGS National Acquisition Branch to The Trustees of Columbia University, NY. The samples will be analyzed at the Noble Gas Laboratory, Lamont-Doherty Earth Observatory, Palisades, NY. The contract provides the following analytical services:
Analysis 1
- Total dissolved Helium in cc at STP per g water.
- Total dissolved Neon in cc at STP per g water.
- 3He/4He isotopic ratio for total dissolved Helium (corrected to date of sample collection, and also reported for the date of extraction of the Helium from the water), expressed as δ3He, where δ3He = (Rs/Ra – 1)100, where Rs is the 3He/4He isotopic ratio of the sample and Ra is the 3He/4He isotopic ratio of air, =1.384 x 10-6.
- Date of extraction of Helium from water sample.
- Associated analytical uncertainty
Analysis 2
- Total dissolved Helium in cc at STP per g water.
- Total dissolved Neon in cc at STP per g water.
- Total dissolved Argon in cc at STP per g water.
- Total dissolved Krypton in cc at STP per g water.
- Total dissolved Xenon in cc at STP per g water.
- 3He/4He isotopic ratio for total dissolved Helium (corrected to date of sample collection, and also reported for the date of extraction of the Helium from the water), expressed as δ3He, where δ3He = (Rs/Ra – 1)100, where Rs is the 3He/4He isotopic ratio of the sample and Ra is the 3He/4He isotopic ratio of air, = 1.384 x 10-6.
- Date of extraction of Helium from water sample.
- Associated analytical uncertainty
Analysis 3
- Dissolved low-level tritium in tritium units (TU) corrected to value at date of collection of water sample, as submitted with water sample.
- Associated analytical uncertainty
The delivery schedule is as follows:
Pricing information is available through the pricing links on the USGS intranet only
Analysis |
Measurement* |
Reporting unit |
Analytical Precision |
Turn-around time (months) |
Former schedule or lab code number |
1 |
Helium, Neon, 3He/4He |
He, and Ne: ccSTPg-1 water; 3He/4He of total dissolved He as δ3He (in %) |
He, 1%; Ne, 2%; δ3He, 1% |
4 |
Schedule 1033 |
2 |
Helium, Neon, Argon, Krypton, Xenon, 3He/4He |
He, Ne, Ar, Kr, Xe: ccSTPg-1 water; 3He/4He of total dissolved He as δ3He (in %) |
He, Ar, Kr, 1%; Ne, Xe, 2%; δ3He, 1% |
4 |
New |
3 |
Tritium |
TU |
(3-10 TU) 5%;(1-3 TU) 10%; (0.3-1.0 TU) 30%; (0.1-0.3 TU) 100% |
6 |
Lab Code 2112 |
1 and 3 |
Helium, Neon, 3He/4He with tritium by 3He ingrowth |
see above |
see above |
6 |
Schedule 1033 and Lab Code 2112 |
2 and 3 |
Helium, Neon, Argon, Krypton, Xenon, 3He/4He with tritium by 3He ingrowth |
see above |
see above |
6 |
New |
* Mass spectrometric |
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|
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The contract permits analysis of the full suite of noble gases. The results include age interpretation only if analysis 3 (tritium) is completed through the contract at Lamont. Information on requesting sample containers, collection procedures and submittal to the Contract Lab is provided at http://water.usgs/gov/lab/3h3he. Please contact the main GW Dating Lab email address, cfc@usgs.gov cfc@usgs.gov, or call 703-648-5847 for further questions.