The geology of Oak Island and Mahone bay is complex in nature. Several different rock formations all formed under varying geological conditions make the bay unique. 

Dating back to the 1867, professionals have speculated the water courses below the island are nothing more than a result of natural processes. Certainly Robert Dunfield Sr, a qualified geologist, drew conclusions for a strike line to have passes directly below the money pit area.

Below is an extract from 11 Jan 1867 Halifax and Sun Advitiser.
 



While water courses and hydraulic connections below the island are a certainty, are they man-made or natural?

The Barringer Very Low Frequency survey of 1988 was disappointing; however, it did show differences between pre and post pumping action resulting in an interpreted water course. The thought to be water course is greater than 20ft in width; thereby, giving support to a natural feature. 

Below are some links to geological sources for Mahone Bay.   


Geological Map of Chester
http://www.gov.ns.ca/natr/meb/data/mapgallery/map/htm/map_1990-009.htm

Till Clast and Glacial Geology of Chester, Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/map/htm/map_1990-004.htm

Map of Meguma Terrane Enhanced (Second Vertical Derivative) Aeromagnetic Digital Data of the Chester Area.
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_1997-028.htm


Preliminary Geological Map of Chester
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_1988-013.htm

Preliminary Gold Compilation Map of the Meguma Terrane In Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_1986-053.htm


Mineral Resource Land-use Map of the Chester Area
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_2000-004_21a09.htm

Surficial Geology Map of the Chester Area
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_1956-079.htm

Airborne Magnetic Map of the Lunenburg Area
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_1957-043.htm


Map of the Gold Deposits of Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_1953-001.htm

Geological Map of the Province of Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/map/htm/map_2000-001.htm

Magnetic Map of Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/map/htm/map_1979-009.htm

Bouguer Gravity Anomaly Map of Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/map/htm/map_1979-008.htm

Principal Classes of Mineral Deposits Map of Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/map/htm/map_1979-007.htm

Metamorphic Map of Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/map/htm/map_1979-006.htm

Structural Map of Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/map/htm/map_1979-005.htm

Map of Geothermal Resource Areas in the Province of Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_2000-008.htm

Geochemical Atlas of Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_1990-015.htm


Preliminary Gold Compilation Map of the Meguma Terrane In Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/pdf/ofm_1986-052_200_cln.pdf

Geological Map of Nova Scotia Showing Barite, Fluorite, and Celestite Occurrences
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_1978-001.htm


Metallic Mineral Map of the Province of Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_1966-015.htm


Probability of Bedrock Occurring Within 10 Feet of the Surface
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_ND-179.htm

Probability of Bedrock Occurring Within 10 Feet of the Surface (not the same as above)
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_ND-180.htm

Drumlin Fields in the Southeastern Shore Area of Nova Scotia
http://www.gov.ns.ca/natr/meb/data/mapgallery/ofm/htm/ofm_ND-177.htm