Tuesday, January 12, 2010

Tracking the Pleistocene jet stream and aquifer recharge on Black Mesa


 A new study in Geology found that ground water from the Navajo sandstone aquifer shows "significant changes in noble gas infusion rates and concentration (particularly neon)... about 25,000 to 40,000 years ago, coinciding with the last Pleistocene ice age, as well as an extraordinary peak of neon associated with a flood of groundwater 14,000 to 17,000 years ago, at which time the southern jet stream hovered above northern Arizona."  [right, age of groundwater in the Navajo sandstone underlying Black Mesa, Arizona. Image by Ruth Droppo. Courtesy of Indiana University]

Ref: Noble gas signatures of high recharge pulses and migrating jet stream in the late Pleistocene over Black Mesa, Arizona, United States, Chen Zhu and Rolf Kipfer, Dept. of Geological Sciences, Indiana Univ., Bloomington, Indiana 47405, USA, doi: 10.1130/G30369.1 v. 38 no. 1 p. 83-86