Noble Gas Geochemistry discusses the fundamental concepts of using noble gases to solve problems in the earth and planetary sciences. The discipline of noble gas geochemistry has become a major branch in the earth and planetary sciences. It offers a powerful and unique tool in resolving problems such as the origin of the solar system, evolution of the planets, Earth formation, mantle evolution and dynamics, atmospheric degassing and evolution, ocean circulation, dynamics of aquifer systems, and numerous applications to other geological problems.

The idea for a special publication on nonvolcanic margins arose during Ocean Drilling Program (ODP) Leg 173 off West Iberia, prompted by ODP's decision to cease publishing the scientific results volumes as hard copy. The Shipboard Scientific Party favoured an open scientific meeting and associated publication. But they did not want to produce a book that was a scientific results volume by another name, but rather contribute to a publication that had a much broader scope than just reporting results obtained off West Iberia.

Both crude oil and natural gas occur naturally in subsurface deposits. Crude oil is a black liquid that is sold to refineries to be refined into products such as gasoline and lubricating oil. Natural gas is a colorless, odorless gas that is sold to gas pipelines to be transported and burned for its heat content. There are many different types of crude oils and natural gases, some more valuable than others. Heavy crude oils are very thick and viscous and are difficult or impossible to produce.

Discovered in 1972, the Amethyst Field is a group of five gas accumulations covering an area of 97 km 2 in the southern North Sea in blocks 47/8a, 47/9a, 47/13a, 47/14a and 47/15a. It is one of the closest fields to the Humberside coast. Gas production started in October 1990.