Helium Isotopes in Nature (eBook)

Front Cover 1
Helium Isotopes in Nature 4
Copyright Page 5
Table of Contents 12
PREFACE 6
Chapter 1. COLLECTION AND PREPARATION OF NATURAL HELIUM SAMPLES FOR MASS-SPECTROMETRIC ANALYSIS 16
1.1. Vessels for collecting and long storage of natural helium samples 16
1.2. Collecting of gaseous and fluid samples 19
1.3. Helium extraction from fluid microinclusions in minerals 21
1.4. Helium extraction from solids 23
1.5. Purification of helium from accompanying gases 31
1.6. A modern all-metal system for extraction and purification of helium 33
Chapter 2. MEASUREMENT OF HELIUM CONTENTS IN SAMPLES HELIUM STANDARDS WITH A GIVEN ISOTOPE RATIO
2.1. Measurement of helium contents in terrestrial gases 36
2.2. Preparation of standard mixtures of 3He and 4He 38
2.3. Helium isotope composition in the lower atmosphere 41
2.4. Universal mass-spectrometer leak-in system for helium isotope studies 44
Chapter 3. PECULIAR FEATURES OF MASS-SPECTROMETRIC ISOTOPE ANALYSES OF TERRESTRIAL HELIUM 48
3.1. Resolution of a mass spectrometer 48
3.2. Background of 4He scattered ions and its suppression in the measurements of very low 3He/4He ratios 49
3.3. Background of scattered HD+ and H3+ ions 53
3.4. "Memory" and other factors affecting the measurements of 3He and 4He abundance in terrestrial samples 55
3.5. Two-beam mode of operation and static mode of pumping a mass spectrometer 58
3.6. Requirements for a mass spectrometer used for natural helium isotope measurements 59
Chapter 4. ISOTOPIC ANALYSIS OF NATURAL HELIUM BY A STATIC MAGNETIC MASS SPECTROMETER 62
4.1. One-stage magnetic static mass spectrometer 62
4.2. Multi-stage static mass spectrometers 65
4.3. Results obtained by means of magnetic static mass spectrometers 68
Chapter 5. MAGNETIC RESONANCE MASS SPECTROMETER (MRMS) 70
5.1. Design and operating principles of the MRMS 71
5.2. Ways to ensure the analytical parameters 76
5.3. A laboratory mass spectrometer 79
5.4. Industrial magnetic resonance mass spectrometer MI 9302 83
5.5. Solution of the most difficult problems of helium isotope studies achieved with the MRMS 86
Chapter 6. LIGHT NOBLE GAS ISOTOPES IN METEORITES 90
6.1. Meteorites and the earth 90
6.2. Primordial noble gases in meteorites 96
6.3. Isotopes of light noble gases in meteorites 102
6.4. Noble gases in the terrestrial atmosphere 109
Chapter 7. HELIUM ISOTOPES IN THE EARTH'S MANTLE 112
7.1. Abundance of 4He and 3He in radiogenic helium 112
7.2. Helium isotopes in mantle materials 119
7.3. On the nature of 3He excess in the earth's mantle 134
7.4. 3He/4He ratio and 20Ne excess in terrestrial samples 136
7.5. Helium/argon isotope relationship 142
Chapter 8. HELIUM ISOTOPES IN ROCKS, WATERS AND GASES OF THE EARTH'S CRUST 150
8.1. Distribution of 3He and 4He in rocks of the earth's crust 150
8.2. The distribution of 3He and 4He in mineral fractions 161
8.3. Helium isotopes in some minerals 167
8.4. Distribution and origin of helium and argon isotopes in gas—liquid microinclusions in minerals 171
8.5. Distribution of helium isotopes in terrestrial gases relationships with geotectonics and heat flow
8.6. The 3H—3He method its application in physical hydrology and limnology
Chapter 9. HELIUM ISOTOPES IN SEAWATER 208
9.1. Origin of helium isotopes in seawater 208
9.2. Distribution of helium isotopes in oceanic waters 214
Chapter 10. HELIUM ISOTOPES IN THE EARTH'S ATMOSPHERE 218
10.1. Distribution of helium isotopes in the atmosphere 218
10.2. Helium isotopes in a "nondissipated" atmosphere 222
10.4. Recent investigations of helium escape 230
Chapter 11. OUTGASSING OF THE MANTLE AND CRUST THE EVOLUTION OF NOBLE GASES IN THE ATMOSPHERE
11.1. The problem of the earth degassing 240
11.2. A model of the earth degassing and differentiation description, assumptions, observations and parameters
11.3. A model of the earth degassing and differentiation evaluation of solutions
CONCLUSIONS 258
REFERENCES 264
SUBJECT INDEX 284