Methods in Palaeomagnetism

Methods in Paleomagnetism covers the proceedings of the NATO Advanced Study Institute on Paleomagnetic Methods, held in the Physics Department of the University of Newcastle upon Tyne on April 1-10, 1964. The book focuses on apparatus and techniques used in paleomagnetism and rock magnetism.
The selection first offers information on sampling techniques in the field and measurement of natural remanent magnetization. Discussions focus on ballistic and spinner magnetometers; paleomagnetic sampling with a portable coring drill; portable apparatus for collecting small oriented cores; and portable field-sampling equipment. The book also takes a look at procedures to test the stability of magnetization, as well as physical properties of demagnetization; thermal demagnetization by the continuous method; and apparatus for thermal demagnetization by the progressive method.
The text ponders on measurement of isotropic and anisotropic susceptibility and magnetic measurements in applied fields. Topics include preliminary account of a refined technique for magnetic susceptibility anisotropy measurement of rocks; errors in anisotropy measurements with the torsion balance; and measurement of the anisotropy of the susceptibility with an astatic magnetometer.
The selection is a valuable reference for readers interested in paleomagnetism.

Contenu

Preface
List of Contributors
Chapter 1. Sampling Techniques in the Field
Notes on Rock Sampling for Paleomagnetic Research
The Collection and Orientation of Rock Samples
The Use of the Sun Compass
Methods of Sample Collection and Orientation for Archeomagnetism
Paleomagnetic Sampling with a Portable Coring Drill
Advantages of Field Drilling of Samples for Paleomagnetic Studies
Portable Apparatus for Collecting Small Oriented Cores
Portable Field-Sampling Equipment
A Large Sampling Drill
Chapter 2. Measurement of Natural Remanent Magnetization
Section I. Astatic Magnetometers
The Design and Construction of Astatic Magnetometers
The Astatic Magnetometers at Newcastle upon Tyne
The Astatic Magnetometers at De Bilt
The Dominion Observatory Astatic Magnetometer
The Astatic Magnetometers Constructed in Paris
The Astatic Magnetometer at the Sedgwick Museum, Cambridge
Two Astatic Magnetometers with Variable Sensitivity
Recent Improvements Carried Out on Astatic Magnetometers
An Automatic Astatic Magnetometer
Preliminary Evaluation of a New Resonance Magnetometer
The Resonance Magnetometer
Section II. Ballistic and Spinner Magnetometers
Principles of The Ballistic Magnetometer for the Measurements of Remanence
Design of Spinner Magnetometers
The Spinner Magnetometer at Salisbury
The Spinner Magnetometer at Newcastle upon Tyne
A Spinner Magnetometer for Igneous Rocks
Design of a Transistorized Portable Air-Turbine Spinner Magnetometer
A "Big Sample" Spinner Magnetometer
Calibration of the Spinner Magnetometer
Section III. Fluxgate Magnetometers
Measurement of N.R.M. with Fluxgate Unit
Measurement of Natural Remanent Magnetization at the Outcrop
Section Iv. Principles of Measurement
The Magnetization of Rock Samples
Methods of Measurement with the Astatic Magnetometer
Shape and Size of Weakly Magnetized Rock Specimens
Analysis of Spinner Magnetometer Operation
Chapter 3. Procedures to Test the Stability of Magnetization
Field Tests for Stability
Physical Principles of Demagnetization
The A.C. Demagnetization Technique
Computations of the Behavior of Two- and Three-Axis Rotation Systems
A 500 C/Sec Alternating Field Demagnetizing Apparatus
Analysis of Alternating Field Demagnetization Equipment
A.C. Demagnetization of Rocks: Analysis of Results
Thermal Demagnetization by the Continuous Method
Apparatus for Thermal Demagnetization by the Progressive Method
Thermal Demagnetization Apparatus at Paris
A "Big Sample" Spinner Magnetometer and Demagnetizing Oven
Chemical Demagnetization
Chapter 4. Presentation and Analysis of Data
Statistics of a Spherical Distribution
Distortion Patterns of Projections and Simple Methods of Constructing Oblique Cases
Statistical Discussion of Magnetization of Rock Samples
Analysis of Paleomagnetic Data
On Estimating Secular Variation From Paleomagnetic Data
Chapter 5. Measurement of Isotropic and Anisotropic Susceptibility
The Anisotropy of Magnetization of Rocks
Measurement of Initial Susceptibility with the Astatic Magnetometer
The Measurement of Anisotropy of the Susceptibility with an Astatic Magnetometer
An Instrument for the Measurement of Isotropic Initial Susceptibility of Rock Samples
An Anisotropy Meter
Torsion-Balance Method of Measuring Anisotropic Susceptibility
Errors in Anisotropy Measurements with the Torsion Balance
Use of the Spinner Magnetometer for Anisotropy Measurements
The A.C. Bridge Method
Preliminary Account of a Refined Technique for Magnetic Susceptibility Anisotropy Measurement of Rocks
Anisotropy Measurements with a Translation Inductometer
Chapter 6. Magnetic Measurements in Applied Fields
Principles of Magnetic Balances
A Fused-Quartz Curie-Point Balance
Recording Magnetic Balance
A High-Frequency Method for the Measurement of Curie Temperatures of Ferrimagnetic Minerals
The Use of a Commercially Available Fluxgate Magnetometer in Determination of the Curie Point of Rock Samples
Vibration Magnetometer
Apparatus for Magnetic Measurements at Low Temperatures
The High-Field Torque-Meter Method of Measuring Magnetic Anisotropy of Rocks
Measurement of High-Coercivity Magnetic Anisotropy
Chapter 7. Techniques for The Study of Magnetic Components in Rocks
The Identification of the Opaque Oxide Minerals by Optical and X-ray Methods
The Determination of Iron and Titanium in Silicate Rocks
Identification of Magnetic Minerals in Rocks Using Methods Based on Their Magnetic Properties
Rock Magnetic Investigations at Low Temperatures
Identification of Magnetic Phases in Certain Rocks by Low-Temperature Analysis
Observation and Interpretation of Magnetic Domains in Natural Magnetite
Chapter 8. Miscellaneous Laboratory Facilities
The Production of High Magnetic Fields for Experiments in Rock Magnetism
Helmholtz Coils and Coil Design
Magnetic Shielding
The Measurement of Stress Effects in Rock Magnetism
A Two-Component Magnetometer Used to Measure Magnetization Changes of Rock Under Uniaxial Compression
Laboratory Redeposition Studies - An Appraisal of Apparatus and Technique
Simple, Order-of-Magnitude Rule for Estimating Stray Fields of Ferrous Components in Laboratory Apparatus
Index