Upgrade of the Noble-Gas Geochronology Laboratory at Lehigh University

Lehigh University, Bethlehem PA

Investigators

Abstract

This project is supporting the updating of Lehigh University's laboratory for argon-argon and uranium-thorium-helium dating. These techniques for dating minerals (termed "noble-gas thermochronology") are relevant to the geosciences because they allow estimates to be made of the time and temperature history of rocks over the range 50 degrees C to 500 degrees C. This is an important temperature range that has bearing on many geological processes, as heat is an important driving agent for many geologic processes (e.g. ore and oil formation) and in turn many of these processes cause temperatures to change within the Earth (e.g., due to erosion in mountainous areas). Noble-gas dating techniques are also used to determine precise ages for geological materials, such as volcanic ashes and lavas, thus allowing calibration of the age of sedimentary sections that contain records of biological evolution, climate variations, and other environmental changes, over a range from 50,000 to more than 500 million years. Knowledge of time and temperature is critical to the understanding of Earth resources, natural hazards, and the basic functioning of Earth systems. The laboratory upgrades are contributing to research infrastructure by facilitating greatly simplified and higher-purity sample preparation, full automation of both the helium- and argon-dating systems to permit higher sample throughput, and improvements in pumping and gas clean-up that will improve the precision of individual analyses. These upgrades are supporting studies of mountain and landscape development in Tibet, Alaska, Central America, and Mongolia by researchers at Lehigh University, as well as collaborative studies with industry and academic researchers at other institutions. These upgrades are providing more ready access to the laboratory by graduate and undergraduate students, exposing more students to modern methods of geological research, thus contributing to teaching and learning.