Laura J. Crossey

Laura J. Crossey is an American hydrologist and geochemist and Distinguished Professor of Earth and Planetary Sciences at the University of New Mexico (UNM). Crossey is part of UNM's Sustainable Water Resources Grand Challenge team, which studies water and climate in New Mexico and other arid regions. She has studied springs and groundwater in areas including the Western Desert of Egypt, Australia's Great Artesian Basin, Tibet,

Early life and education Laura Jones Crossey grew up in Deerfield, Illinois. As Dean of Research, she helped to arrange a climate-controlled home for the paleontology collection, then housed in Northrop Hall, later the Natural History Science Center. As of 2021, Crossey was named a Distinguished Professor of Earth and Planetary Sciences at the University of New Mexico.

Research

Crossey studies hydrology and low-temperature geochemistry with applications to hydrochemistry, paleohydrology, diagenesis, geothermal systems, geomicrobiology, microbial ecology, aquifers, groundwater sapping, aquatic nutrient cycling, microbial diversity in springs, sandstone cementation, mantle degassing and planetary impact events.

One of Crossey's areas of study is the formation of travertines and springs.

Crossey has spent years studying the relationships between geology and hydrology in the Grand Canyon region, identifying hydrologic boundaries and tracking the flow of groundwater between its aquifers. She models the movement, mixing, and quality of water through the region and has raised concerns about the many demands on the canyon's water supply.

Crossey also investigates the age of the Grand Canyon, through studies of its rock layers and their composition. Thermal histories of apatite rock samples suggest that the Colorado River is made up of multiple segments that were formed at different times, the youngest of them around six million years ago. The study and dating of fossils has led the researchers to redefine the Tonto Group formation to include the Sixtymile Formation. This work suggests a younger age for the Tonto Group than previously thought, possibly 508 to 497 million years, and a recalibration of the Cambrian timescale. Key extinctions during the Cambrian period may have occurred more quickly than previously believed.

As a result of her research on the Grand Canyon Crossey has worked with Grand Canyon National Park to educate the general public about geoscience and the groundwater systems of the region.

Crossey does interdisciplinary research with the Center for Water and the Environment (CWE) to address issues of water scarcity and sustainability.

Crossey has carried out water geochemical analyses of water samples from hot springs in Tibet in collaboration with scientists from the national Chinese Academy of Sciences, Stanford University, and Ohio State University. Over nearly a decade, scientists traveled thousands of kilometers to sample 225 hot springs, some boiling. The location and chemical composition of water in the hot springs has helped scientists to map the subsurface boundary, where the Indian and Asian continental plates collide to form the Himalayan Mountains and the Tibetan Plateau. By measuring mantle-derived helium (3He) scientists were able to detect a 1,000 kilometer long boundary extending east–west from longitude 80 to 92 along the Indus-Yarlung suture zone in southern Tibet. To the south, on the Himalayan side, the Indian and Asian plates lie on top of each other in a thick layer that blocks the diffusion of mantle-derived helium. To the north, mantle-derived helium was detected in springs, indicating that there the Indian plate is subducting, or dropping away, from the Asian plate. Towards the eastern end, results suggest that the collision process is tearing up the Indian plate. This research may resolve contradicting theories and lead to a better understanding of how tectonic plates collide.

Crossey also works with the Institute of Meteoritics at the University of New Mexico.

Awards and honors 2021, Distinguished Professor of Earth and Planetary Sciences at the University of New Mexico 2019, Birdsall-Dreiss Distinguished Lecturer, Hydrogeology Division, Geological Society of America 2015, Outstanding Achievement Award for Major Contribution to the Profession, American Institute of Professional Geologists (with Karl Karlstrom) 2015, Impact Award, New Mexico Network for Women in Science and Engineering 2015, Lifetime Membership, New Mexico Geological Society 2011, First Place Award for Wayside Exhibits, National Association for Interpretation (with Karl Karlstrom)

Selected publications