[This is a speculative post about possible Native American names of local water features, including the Geddes Brook.]
The 1851 “Morgan map” of Haudenosaunee placenames can currently be found at the Cayuga County genealogy website. This map purports to show placenames circa 1720, and it does agree with other 19th century sources such as William Beauchamp’s “Aboriginal PLace Names of New York” and the “Life of Mary Jemison.” The name O-ya-han (“Apples Split Open”) has been generally thought to be the old name for Camillus (somewhere in the township, if not the village itself). However, the Morgan map, although distorted, seems generally accurate in terms of lakes and rivers/creeks… which makes it seem very likely that Geddes Brook is represented here also (easily seen joining Nine Mile Creek “Usteka” southeast of Onondaga Lake “Gannentaa“).
Although Geddes Brook here seems conflated with Harbor Brook (forming a hydrologically impossible ring), it appears to be labeled “De-o-na G.” (G. being an abbreviation for the native word for “creek”).
A bit more Googling brings up Beauchamp’s discussion of the names on various source lists and on Morgan’s map of Onondaga County placenames… including a mysterious watercourse called “De-o-nake-ha-e” which is in a list by Morgan for Onondaga County, but not on his map. In any case, it is purported to be the old name for something called “Oil Creek,” which flummoxes Beauchamp because there simply isn’t any place called “Oil Creek” in Onondaga County. (And the name “De-o-nake-ha-e” is said in Beauchamp to mean “oily water.” No creeks in Onondaga County have historically had this reputation.)
So, we have a creek in pretty much the location of Geddes Brook, labeled “De-o-na.” We have an unlocated mystery creek called “De-o-nake-ha-e.” But if Geddes Brook is in fact this mystery creek, what could the “oily water” reference be about?
We also have several 19th-century accounts of Geddes Brook, from visitors to the Geddes farm, which mention that the waters of the creek at that time were filled with marl (calcium carbonate deposits, specifically tufa, probably courtesy of the limestone that the brook percolates down through at Split Rock). Marl is not necessarily a whitish substance, and can also appear in water as a slimy brown muddy substance, coating rocks and plants. (Marl-loving plants, such as Chara, were observed to be growing rampant in Geddes Brook by Frederick Pursh in 1807.) Perhaps the native word interpreted as “oil” has more than one meaning.
Further investigation of this theory is welcomed, especially concerning the history of the Morgan Map and its interpretation; and of course, any information directly from Onondaga people about local water features, or information from those familiar with the Onondaga language or other Haudenosaunee languages.