Isotopic Analysis CODE 10B Ages of geological formations or secondary events ie alteration or metamorphism can be determined through using KAr Ar Ar UPb RbSr or the SmNd dating methods These analytical procedures include several steps i dating method selection ii sample collection iii sample preparation mineral separation and treatment iv irradiation of the samples in a nuclear reactor for the ArAr technique v high precision determination of the concentration of the mother and daughter isotopes by TIMS thermal ionization mass spectrometry vi apparent age calculation and interpretation of the results The dating strategy depends on the type of formation magmatic metamorphic or sedimentary the sample composition and the age of the formation The concentration of the mother and the daughter isotopes as well as the apparent age can be determined with high precision In m any cases however the determined age may not be the real age of the geological event The apparent age may be af fected by the postdepositional or postformati on history of the rocks Natural contamination of chemical sediments with detrital material can also af fect the results of dating of diagenesis There are some techniques and calculations which can look through the post formation event These include isochron dating K Ar UPb RbSr and SmNd or the step heating ArAr technique of the KAr method In the ArAr technique the K and Ar are measured on the same sample aliq uot First the sample is irradiated in a nuclear reactor where fast neutrons convert some of the 39 K to 39 Ar After irradiation the Ar is released fractionally by incremental heating The result is a series of apparent ages from which useful information about the geologic history and the age of the sample can be inferred Specific techniques for dating clay fractions have also been developed Our geochronological services provide dating methods for all types of geological samples through use of modern analytical facil ities W e can advise on selecting the method of dating sampling and interpretation of the data so that meaningful geological results are obtained For the dating of a monomineralic sample only tens of milligrams of sample are required For rocks a few hundred milligrams a re typically used for analysis Size of the rock sample required will vary considerably for mineral separation depending on which minerals must be separated and the amount and type of the accessory minerals present Services Offered Parameter Amt Required Precision P rice Pb Isotopic analysis by HRICPMS Pb 15ppm 110 samples 1 g 04 05 21000 Pb Isotopic analysis by HRICPMS Pb 15ppm 10 samples 1 g 04 05 15500 Pb Isotopic analysis by TIMS 1 g 01 02 4700 0 Nd Isotopic Analysis by TIMS 1 g 47000 Sr Isotopic Analysis by TIMS 1 g 47000 SmNd Isotopic Analysis by TIMS 1 g 68000 RbSr Isotopic Analysis by TIMS 1 g 68000 Hg Isotopic Analysis by multicollector ICPMS 1 g On request 1 3 C Graphite or Organic Material 1 mg C 02 19000 1 3 C and 18 O Carbonates 1 mg C 02 15500 1 3 C and 18 O Siderite Magnesite Dolomite 1 mg C 02 19000 Nitrogen Isotopes Organic Material 15500 Deuterium Isotopic Analysis W ater 20 ml 30 18500 Deuterium Isotopic Analysis Minerals 1 mg 02 42500 1 8 O W ater 20 mL 02 1600 0 1 8 O Silicates 15 mg 03 3750 0 1 8 O Sulphates 25 mg 03 18000 1 8 O Organics 10 mg N 02 20000 3 4 S Sulphate 10 mg 02 1 1500 3 4 S Sulphate in water 18500 3 4 S Sulphide 5 mg 02 1 150 0 3 4 S Sulphidebearing material which contains carbonate 100 mg 02 16000 3 4 S Silicate rocks which contain sulphur 16000 3 H Direct 20 mL 80 TU 1 6000 3 H Enriched 1L 08 TU 4 3000 3 H Accelerator Mass Spectrometry AMS 70000 10 B Analysis Description Price KAr dating Rock fractions clay fractions and separated minerals On request eg biotite hornblende sericite Kfeldspar illite glauconite etc KAr dating in duplicate T wo independent measurements on one sample On request 40 Ar 39 Ar step heating dating Rock fractions clay fractions or separated minerals On request eg biotite hornblende sericite Kfeldspar illite glauconite etc UPb dating by TIMS Single grain analysis eg zircon monazite titanite apatite On request UPb isochron dating by SHRIMP Single grain analysis On request RbSr dating by TIMS Isochron dating whole rock and minerals On request SmNd dating by TIMS Isochron dating whole rock and minerals On request ReOs dating ReOs dating On request Petrographic description Includes thin section preparation On request Mineral Separation Specific mineral phases are separated to provide best data for age dating On request Geochronology Advice concerning dating strategies and interpretation of data is provided as required Discounts may be applicable for large dating pro grams For more information please contact Dr Y akov Kapusta kapusta actlabscom or at 905 648961 1 CODE 10A When submitting samples please supply details on rock or mineral type and alter ation P AGE 36