"VALUE ADDED" GEOLOGIC MAPPING: CASE HISTORIES FROM EASTERN MAINE

Geologic mapping gets no respect – especially in this Section. In states and provinces where geologic resources are major components of the economy and volcanoes and earthquakes are everyday threats, legislators, the public, and academia understand the value of basic geologic mapping. This “value added” side of geologic mapping is less well understood in the NE Section, even though data from basic mapping also enriches our economy, mitigates disasters, and preserves our water supply. This presentation discusses selected examples of the added value of my mapping in eastern Maine, instances where the geologic map solved problems, improved resource potential, or contributed to environmental decisions. These case histories involve several economic and environmental areas, although the mapping was not conducted to address any of these issues:

Forestry: 7½' quadrangle map enabled a lumber company to select trees with the least heartwood and as a result maximize output of plywood veneer – based on Mn content in one member of a Silurian formation.

Mineral resources: (1)abundant large andalusite porphyroblasts in a contact aureole attracted the attention of a Fortune 100 company wishing to make refractory brick and spark plugs; (2) contact between Ordovician volcanic section and intrusive granite interested prospectors who had discovered gold in a similar aureole in New Brunswick.

Groundwater quality: extremely high arsenic content of private wells in one town was quickly related to a stratigraphic source – a formation defined during my 1:24,000 mapping. The 100,000 scale map predicted areas where the problem could also be expected to occur.

Environmental engineering: predicted (prediction ignored) leakage of pulp mill effluent from federally mandated water treatment facility caused by two intersecting fault systems. Later helped mitigate the problem and testified during litigation to recover costs of remediation .

Fish ecology: helped biologists understand pH variation in streams draining a single formation—tied to conversion of calcareous wacke to calc-silicate bearing granofels.