Laura J. Crossey is an American hydrologist and geochemist and Distinguished Professor of Earth and Planetary Sciences at the University of New Mexico (UNM).

[8] 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.

[3][11] Crossey studies hydrology and low-temperature geochemistry with applications to hydrochemistry, paleohydrology, diagenesis, geothermal systems, geomicrobiology, microbial ecology,[7] and planetary geology.

[3] She carries out field studies and laboratory analysis of water, sediments, geomicrobial materials and gases, and examines core samples and surface features of geological formations.

[12] Her publications address topics such as continental smokers,[7] sediment burial,[14] groundwater sapping,[15] aquatic nutrient cycling, microbial diversity in springs, sandstone cementation, mantle degassing and planetary impact events.

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.

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.

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.