Estimation of Alluvial-Fill Thickness in the Mimbres Ground-Water Basin, New Mexico, from Interpretation of Isostatic Residual Gravity Anomalies
The geologic structure of the Mimbres ground-water basin in southwest New Mexico is characterized by north- and northwest-trending structural subbasins. Sedimentation of Miocene and Pliocene age has filled and obscured the boundaries of these subbasins and formed potentially productive aquifers of varied thickness. The location and depth of the subbasins can be estimated from analysis of isostatic residual gravity anomalies. Density contrasts of various basement lithologies generate complex regional gravity trends, which are convolved with the gravity signal from the Miocene and Pliocene alluvial fill. An iterative scheme was used to separate these regional gravity trends from the alluvial-fill gravity signal, which was inverted with estimated depth-density relations to compute the thickness of the alluvial fill at 1-kilometer spacing. The thickness estimates were constrained by exploratory drill-hole information, interpreted seismic-refraction profiles, and location of bedrock lithology from surficial geologic mapping. The resulting map of alluvial-fill thickness suggests large areas of thin alluvium that separate deep structural subbasins.
Heywood, C.E., 2002, Estimation of alluvial-fill thickness in the Mimbres ground-water basin, New Mexico, from interpretation of isostatic residual gravity anomalies: U.S. Geological Survey Water-Resources Investigations Report 02-4007, 16 p., https://doi.org/10.3133/wri024007.
Table of Contents
- Isostatic residual gravity field in the Mimbres Basin
- Alluvial-fill thickness in structural subbasins
- Selected references
Additional publication details
|Publication Subtype||USGS Numbered Series|
|Title||Estimation of alluvial-fill thickness in the Mimbres ground-water basin, New Mexico, from interpretation of isostatic residual gravity anomalies|
|Series title||Water-Resources Investigations Report|
|Publisher||U.S. Geological Survey|
|Publisher location||Reston, VA|
|Contributing office(s)||New Mexico Water Science Center|
|Description||iv, 15 p.|