Revision History for U.S. Geological Survey Scientific Investigations Report 2018–5003

By Nick Teague, John Izbicki, Jim Borchers, Justin Kulongoski, and Bryant Jurgens

Hydrogeologic Controls and Geochemical Indicators of Groundwater Movement in the Niles Cone and Southern East Bay Plain Groundwater Subbasins, Alameda County, California

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Posted online February 1, 2018

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Ver. 1.1 Revised and reposted February 1, 2019

The text version was modified.

Interpretation of Carbon-14 Data, pg. 30 [foot of column 1] –
"If a barrier to groundwater flow near the transition zone is present that was not discernible from water-level data, changes in groundwater age across this area may be used to detect the barrier (Izbicki and Martin, 1997)."
Revised to become: “Restriction of groundwater flow near the transition zone that was not discernible from water-level data can be detected using groundwater ages of water from wells across the area (Izbicki and Martin, 1997).”

Pg. 33 [near head of column 2]–
"These results are consistent with lithologic changes (Luhdorff and Scalmanini Consulting Engineers, 2003) within the transition zone that separates the two groundwater subbasins and acts as a barrier to flow between the Niles Cone and southern East Bay Plain groundwater subbasins."
Revised to become: “These results are consistent with lithologic changes (Luhdorff and Scalmanini Consulting Engineers, 2003) within the transition zone that separates the two groundwater subbasins and acts to limit flow between the Niles Cone and southern East Bay Plain groundwater subbasins.”

SUMMARY, Pg. 34 [end of first paragraph]–
"Fine-grained sediments deposited between the alluvial fans of the Niles Cone and southern East Bay Plain groundwater subbasins interrupt lateral continuity of coarse-grained layers and may inhibit interfan flow of groundwater."
Revised to become: “Fine-grained sediments deposited between the alluvial fans of the Niles Cone and southern East Bay Plain groundwater subbasins interrupt lateral continuity of coarse-grained layers and may restrict interbasin flow of groundwater.”

Pg. 34[last sentence of the third paragraph] -
"Changes in the slope of the water-level contours near the transition zone between the Niles Cone and southern East Bay Plain groundwater subbasins are consistent with changes in lithology, or could indicate structural features such as faults or folds, that impede groundwater flow."
Revised to become: " Changes in the slope of the water-level contours near the transition zone between the Niles Cone and southern East Bay Plain groundwater subbasins are consistent with changes in lithology, or could indicate structural features such as faults or folds, that restrict groundwater flow." 

Pg. 35 – [near foot of first column]--
"These results are consistent with lithologic changes within the transition zone that acts as a barrier to flow between the two groundwater subbasins."
Revised to become: "These results are consistent with restricted groundwater flow between the two groundwater subbasins and consistent with the result of lithologic changes within the transition zone and converging groundwater flowpaths north of the transition zone.”

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