Ambrosia rise

Keyword Definition

Stratigraphic marker of Ambrosia pollen.  It indicates the onset of settlement in Southern Ontario (1850-1890).

From the viewpoint of the acid precipitation problem, the Ambrosia rise is important because it provides a datum below which changes in pH (and other parameters) in the lake were due only to natural causes and above which the natural changes may be affected by man's activities. (from Ontario Geological Survey OFR5342 by J.A.C. Fortescue, p. 13)

Source: Ontario Geological Survey

Category: Geological

Geological keywords, such as “granite”, “lake”.  The definitions are generally taken from the AGI Glossary of Geology.  Keywords with a geographic context (e.g. Cape Smith Fold Belt, Selwyn Basin, Grenville Province) are assigned to a separate category.

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