This research includes a hydrogeologic assessment in and around La Union, Honduras to determine the contribution of groundwater to the surface water system and understand the geological control of groundwater storage and movement. Field methods were employed and focused on spring characterization, geochemical signatures, and structural data. Field data was gathered, and locations determined using cellular-integrated GPS signal and the Fulcrum mapping software mobile application. During the summer of 2017, data on 111 geologic points and 34 water points were collected to understand the hydrogeology of the region. Streams and springs were monitored for pH, flow characteristics and conductance as a measure of total-dissolved-solids (TDS). TDS ranged from 22.6 to 485 mg/L with higher values indicating groundwater influx into the surface system. In comparison, lower TDS values are attributed to runoff. Structural information was collected using a Brunton transit compass for strike and dip of lithologic contacts. Structural trends include strikes around 240 degrees, dip direction and approximate magnitudes at 330 and 40 degrees, respectively. Geologic data indicate significant structural deformation, supportive of tectonic activity in the region. For many of the springs in this area, the data can be used to interpret that water is stored in the Jaitique Formation as a perched aquifer controlled by stratigraphy and structure. The groundwater moves down dip through secondary porosity in the Jaitique Formation until it comes into contact with the Lower Valle de Angeles. This Lower Valle de Angeles unit acts as an aquiclude preventing percolation into the ground and resulting in springs at the surface.
Sparks, C. Renee; Jacques, Issac J.; Verbree, Cheryl L.; Timmermans, Thomas J.; and Dykstra, Stuart
"Characterization of Surface Geology and Hydrogeology in the Upper Ulua River Basin, Honduras,"
The Compass: Earth Science Journal of Sigma Gamma Epsilon:
1, Article 3.
Available at: https://digitalcommons.csbsju.edu/compass/vol91/iss1/3
Table 1 - Geologic data points near La Union, Lempira, Honduras
Table 2 - Hydrologic data points near La Union, Lempira, Honduras.xlsx (13 kB)
Table 2 - Hydrologic data points near La Union, Lempira, Honduras