Digby Gut a Drowned River EarthCache

Digby Gut a Drowned River

The Digby Gut is a narrow channel connecting the Bay of Fundy with the Annapolis Basin. The town of Digby, Nova Scotia is located on the inner portion of the western side of the Gut while the town of Annapolis Royal is on the eastern side. The eastern entrance is marked by the Point Prim Lighthouse. Strong tidal currents, numerous rocky ledges, frequent fogs and unpredictable winds make it a dangerous passage. Tide flows create 5 knot tidal currents and create numerous whirlpools and eddies as the water enters the Gut.

The Gut is about a half nautical mile in width and bordered by high rocky cliffs. It marks a break in the North Mountain ridge along the Annapolis Valley and is the eastern end of Digby Neck. Digby Gut had its origins as the northern terminus of the ancient Bear River, part of which is now a drowned river valley.

Bear River

The Bear River is a minor river in western Nova Scotia, Canada. Flowing from south to north, it is 40 kilometres (25 mi) long from its headwaters to its discharge into the Annapolis Basin, some 6 kilometres (3.7 mi) east of Digby. The river is tidal for the last 9.7 kilometres (6.0 mi) of its length. The river forms part of the boundary between Annapolis and Digby Counties. The deeply cut valley, hewn from the contact between slate bedrock on the west and granite on the east, is a drowned river valley of which Digby Gut on the Bay of Fundy forms the northern extreme

Drowned river valley

Drowned river valleys are also known as coastal plain estuaries (Ria). In places where the sea level is rising relative to the land, sea water progressively penetrates into river valleys and the topography of the estuary remains similar to that of a river valley. This is the most common type of estuary in temperate climates. The width-to-depth ratio of these estuaries is typically large, appearing wedge-shaped (in cross-section) in the inner part and broadening and deepening seaward. Water depths rarely exceed 30 m (100 ft).

Geology

The Digby Gut outlet was blocked by a late-melting or re-advancing local glacier. The lake ages provided suggest that the outlet was deglaciated between 14 and 13 ka, and was never overridden by late ice. With both eastern and western valley outlets blocked by ice, an ice-dammed lake would likely have exceeded 35 m in elevation. 

What Caused the Digby Gap

The North Mountain Basalt is continuous from North Mountain across the inner south coastal area of the Bay of Fundy to the contact with the overlying Scots Bay Formation. Faults are mapped in the North Mountain Basalt at Digby Gut and other topographic offsets in North Mountain. Some of these offsets are occupied by water gaps but the faults do not extend into the overlying Triassic sandstone. This indicates that they are likely very old and inactive faults.

To log this Earthcache visit the viewing location.  Please answer the following questions and send in a timely manner to my geocaching profile or email. Answers not received will result in deleted logs.

Note the Digby Gut basin is very large and there are many great viewing points. We have provided an additional 2 for your viewing pleasure. The answers can be obtained from any of them.

Questions:

1. What is the estimated width of the Gut opening?

2. At what time does the Gut basin have more freshwater than salt? 

3. What is the Gut basin used for today? 

4. Post a picture in your log with a personal item or hand in picture to prove you were there.

[REQUIRED] In accordance with the updated guidelines from Geocaching Headquarters published in June 2019, photos are now an acceptable logging requirement and WILL BE REQUIRED TO LOG THIS CACHE. Please provide a photo of yourself or a personal item in the picture to prove you visited the site.