LaHave Islands EarthCache

LaHave Islands

LaHave is a Canadian community in Lunenburg County, Nova Scotia. The community is located across the river from Riverport and approximately 15 kilometres from the town of Bridgewater. Once the capital of Acadia, it is located on Highway 331 at the mouth of the 97 km long LaHave River. LaHave was an important centre for the Mi'kmaq people, who traded with Europeans. Messamouet, a well-known sakmow, or Chief, of the Mi'kmaq Nation, is reported to have been from the La Have area.

The LaHave islands are west of the river mouth and community. A few of the islands are tied to the mainland now with a tombolo and bridges.

Archipelago

An archipelago is an area that contains a chain or group of islands scattered in lakes, rivers, or the ocean. Most archipelagos are formed when volcanoes erupt from the ocean floor; these are called oceanic islands. Archipelagos can also form as a result of erosion, sedimentary deposits, rising sea level, and other geographic processes. Continental fragments are archipelagos that have separated from a continental land mass due to the Earth’s tectonic movements. It the case of the LaHave islands it appears they have been formed from a combination of sedimentary deposits and tectonic action.

Geology

Most of the islands are mostly made of Goldenville Group metasediments from the early Cambrian to Early Ordovician periods. It is interesting to note the purple lines are much older from the Late Triassic. The Cambrian Period was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian Period lasted 55.6 million years. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change.

Metasediment

A metasediment is a rock of sedimentary origin that has been subjected to metamorphism. Such a rock was first formed through the deposition and solidification of sediment. Then, the rock was buried underneath subsequent rock and was subjected to high pressures and temperatures, causing the rock to recrystallize. Recrystallization is a metamorphic process that occurs under temperature and pressure where atoms of a mineral are reorganized by diffusion and/or dislocation glide. Most metamorphic processes take place deep underground, inside the earth’s crust.The Goldenville Group is a group of Cambrian metasediments dominated by psammite (meta-sandstone), with subordinate pelitic rocks (metasiltstone, slate, argillite)

Meta-siltstones are solid sedimentary rocks containing some clay material.

Metasandstone is a metamorphic rock formed by the action of tectonic forces on sedimentary rock (sandstone)

Argillite is a fine-grained sedimentary rock composed predominantly of indurated (hardened) clay particles.

LaHave Islands (Archipelago)

The Islands were created from sand and clay that was deposited during the Cambrian period and experienced millions of years of extreme heat and tectonic plate action to form their solid metaseditment base. Even after numerous glacial events, shifting continents and rising sea levels they are still here for us to enjoy.

To log this Earthcache visit the viewing locations.  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.

To complete this earthcache visit ground zero and the other reference points.

Ground zero, Wolf Gut - N44° 13.404' W64° 21.991'

Bush Island Ramp 2 Boat launch - N44° 14.350' W64° 22.211'

Bush Island Ramp 3 Boat launch - N44° 14.048' W64° 22.366'

Historical Church - N44° 13.430' W64° 21.574'

Beach Parking  - N44° 13.756' W64° 23.184'>

Second Beach - N44° 13.713' W64° 23.172'

Rock example - N44° 13.717' W64° 23.205'

Questions

1. As you drive across the connected islands, count how many islands you see in total? You can use the reference points to get more views. Don’t forget to count on both sides.

2. At one of the reference points or Rock example stop and describe the texture of the metasediment stone foundation rock? Does it have striations and if so how many? (not the rocks used for breakwaters)

3. Why has this type of sandstone/siltstone rock not eroded faster?

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.