Bedrock location, groundwater and acid neutralization in the Lakes of the Clouds watershed, Mount Washington, New Hampshire
- Bates Coll., Lewiston, ME (United States). Dept. of Geology
This study undertakes the goal of mapping bedrock lithology combined with analyzing low temperature bedrock-water interactions to determine possible ion contributions which alter the acidity of water. Originally mapped by Marland Billings at a much larger scale, this study concentrates on the bedrock geology in a less than a one kilometer square area located between Mt. Monroe and Mt. Washington in the Presidential range of New Hampshire. Ground magnetometer transects help determine and constrain the geology of the surface and subsurface bedrock. Optical mineralogy on thin sections from each of the lithologies will determine mineral assemblages. Locally present formations include the Devonian Littleton, and the Silurian Smalls Falls, and Madrid. These are intruded by the Bickford Granite (Devonian) and Mesozoic( ) dikes. Precipitation in the Lake of the Clouds watershed is acidic. Rainwater from this area has a pH range of 4.0 to 4.7. In comparison, groundwater samples ranges from pH 4.5 to 5.5. This rise in pH may be due to a neutralization reaction during the water's residence in the bedrock. In the laboratory, atomic absorption/emission analysis, for the elements calcium, magnesium, potassium and sodium have identified certain neutralizing cations present in groundwater. Continued atomic absorption/emission analysis of natural acid precipitation filtered through crushed rock samples isolates individual cation contributions from each lithology. SEM/EDS analysis of thin sections from the local bedrock lithologies has identified high concentrations of neutralizing cations available in the Madrid formation. Fast X-ray maps indicate that tremolite and diopside within the Madrid formation contain high concentration of calcium, which has been observed in the natural groundwater system as a neutralizing agent.
- OSTI ID:
- 5820234
- Report Number(s):
- CONF-9303211-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 25:2; Conference: 28. annual Geological Society of America (GSA) Northeastern Section meeting, Burlington, VT (United States), 22-24 Mar 1993; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
58 GEOSCIENCES
GEOLOGIC FORMATIONS
HYDROLOGY
GROUND WATER
ROCK-FLUID INTERACTIONS
WATER CHEMISTRY
NEW HAMPSHIRE
ACID NEUTRALIZING CAPACITY
DEVONIAN PERIOD
ION EXCHANGE
LAKES
LITHOLOGY
MAPPING
MINERALOGY
PH VALUE
SILURIAN PERIOD
CHEMISTRY
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGY
HYDROGEN COMPOUNDS
NORTH AMERICA
OXYGEN COMPOUNDS
PALEOZOIC ERA
PETROLOGY
SURFACE WATERS
USA
WATER
540210* - Environment
Terrestrial- Basic Studies- (1990-)
540250 - Environment
Terrestrial- Site Resource & Use Studies- (1990-)
580000 - Geosciences