The Bay of Fundy, Canada

The Bay of Fundy (French: Baie de Fundy) is a bay on the Atlantic coast of North America, on the northeast end of the Gulf of Maine between the Canadian provinces of New Brunswick and Nova Scotia, with a small portion touching the U.S. state ofMaine. Some sources believe the name "Fundy" is a corruption of the French word "Fendu", meaning "split", while others believe it comes from the Portuguese funda, meaning "deep". The bay was also named Baie Française (French Bay) by explorer/cartographer Samuel de Champlain during a 1604 expedition led by Pierre Dugua, Sieur de Monts which resulted in a failed settlement attempt on St. Croix Island.

The Bay of Fundy is known for having the highest tidal range in the world. Rivaled by Ungava Bay in northern Quebec, King Sound in Western Australia, Gulf of Khambhat in India, and the Severn Estuary in the UK, it has one of the highest vertical tidal ranges in the world. The Guinness Book of World Records (1975) declared that Burntcoat Head, Nova Scotia has the highest tides in the world:

“The Natural World, Greatest Tides: The greatest tides in the world occur in the Bay of Fundy.... Burntcoat Head in the Minas Basin, Nova Scotia, has the greatest mean spring range with 14.5 metres (47.5 feet) and an extreme range of 16.3 metres (53.5 feet).”

Portions of the Bay of Fundy, Shepody Bay and Minas Basin, form one of six Canadian sites in the Western Hemisphere Shorebird Reserve Network, and is classified as aHemispheric site. It is administered by the provinces of New Brunswick and Nova Scotia, and the Canadian Wildlife Service, and is managed in conjunction with Ducks UnlimitedCanada and the Nature Conservancy of Canada.

In July 2009, the Bay of Fundy was named as a finalist for the New 7 Wonders of Nature contest that ended in November 2011. It was not chosen as a wonder.

The Bay of Fundy lies in a rift valley called the Fundy Basin; as the rift began to separate from mainland North America, volcanic activity occurred, forming volcanoes and flood basalts. These flood basalts poured out over the landscape, covering much of southern Nova Scotia. Sections of the flood basalts have been eroded away, but still form a basaltic mountain range known as North Mountain. As a result, much of the basin floor is made of tholeiitic basalts giving its brown colour. The rift valley eventually failed (see aulacogen) as theMid-Atlantic Ridge continued to separate North America, Europe, and Africa.

The upper part of the bay splits into Chignecto Bay in the northeast and the Minas Basin in the east. Chignecto Bay is further subdivided into Cumberland Basin and Shepody Bay and the extreme eastern portion of Minas Basin is called Cobequid Bay. Some of these upper reaches exhibit exposed red bay muds, for which the Bay of Fundy is noted (for their appearance and biological productivity).

Cape Chignecto defines Chignecto Bay whereas Cape Split defines the Minas Channel, leading to the Minas Basin. The Minas Channel connects the Minas Basin with the main body of the bay. The channel is 5.6 kilometers across and approximately 106.7 meters deep. The tides that flow through the channel are very powerful. They are as powerful as 8000 train engines or 25 million horses.  Facing Cape Split at the entrance to the Minas Channel are the basalt cliffs ofCape d'Or.

The lower part of the bay is also home to four important sub-basins: Passamaquoddy Bayand Back Bay on the New Brunswick shore, Cobscook Bay on the Maine shore, and theAnnapolis Basin on the Nova Scotia shore.

The bay is home to several islands, the largest of which is Grand Manan Island at the boundary with the Gulf of Maine. Other important islands on the north side of the bay includeCampobello Island, Moose Island, and Deer Island in the Passamaquoddy Bay area. Brier Island and Long Island can be found on the south side of the bay while Isle Haute is in the upper bay off Cape Chignecto. Smaller islands and islets also exist in Passamaquoddy Bay, Back Bay, and Annapolis Basin. The Five Islands, in the Minas Basin, are particularly scenic.

The Bay of Fundy is also home to another interesting geologic feature, the Hopewell Rocks formation. This formation is where the “famous flower-pot rocks” are located on a short, one kilometer long portion of Shepody Bay. These rocks are shaped by the tides, the strength of the rocks, and the presence of the joints in the rocks. The rock in the cliffs the stacks are being cut from are arkosic sandstone and coarse poorly sorted conglomerates. The tides that are eroding away the cliffs are between 10.7 meters and 14.7 meters high on average.

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Halong Bay, Vietnam

Hạ Long Bay (Vietnamese: Vịnh Hạ Long, literally: "descending dragon bay") is a UNESCO World Heritage Site, and a popular travel destination, in Quảng Ninh Province, Vietnam. Administratively, the bay belongs to Hạ Long City, Cẩm Phả town, and part of Vân Đồn District. The bay features thousands of limestone karsts and isles in various sizes and shapes. Hạ Long Bay is a center of a larger zone which includes Bái Tử Long bay to the northeast, and Cát Bà islands to the southwest. These larger zones share similar geological, geographical, geomorphological, climate, and cultural characters.

Hạ Long Bay has an area of around 1,553 km², including 1,960–2,000 islets, most of which are limestone. The core of the bay has an area of 334 km² with a high density of 775 islets. The limestone in this bay has gone through 500 million years of formation in different conditions and environments. The evolution of the karst in this bay has taken 20 million years under the impact of the tropical wet climate. The geo-diversity of the environment in the area has created biodiversity, including a tropical evergreenbiosystem, oceanic and sea shore biosystem.

Hạ Long Bay is home to 14 endemic floral species and 60 endemic faunal species.

Historical research surveys have shown the presence of prehistorical human beings in this area tens of thousands years ago. The successive ancient cultures are the Soi Nhụ culture around 18,000–7000 BC, the Cái Bèo culture 7000–5000 BC and the Hạ Long culture 5,000–3,500 years ago. Hạ Long Bay also marked important events in the history of Vietnam with many artifacts found in Bài Thơ Mount, Đầu Gỗ Cave, Bãi Cháy.

500 years ago, Nguyễn Trãi praised the beauty of Hạ Long Bay in his verse Lộ nhập Vân Đồn, in which he called it "rock wonder in the sky". In 1962, the Ministry of Culture, Sports and Tourism of North Vietnam listed Hạ Long Bay in the National Relics and Landscapes publication. In 1994, the core zone of Hạ Long Bay was listed by UNESCO as a World Heritage Site according to criterion vii, and listed for a second time according to criterion viii.

In 2000, the UNESCO’s World Heritage Committee has inscribed the Hạ Long Bay in the World Heritage List according to its outstanding examples representing major stages of the Earth’s history and its original limestone karstic geomorphologic features. The Hạ Long Bay and its adjacent areas consist of a part of the Sino-Vietnamese composite terrane having its development history from pre-Cambrian up to present day. During Phanerozoic, terrigenous, volcanogenic and cherty-carbonate sediments containing in abundance graptolites, brachiopods, fishes, corals, foraminiferas, radiolarias, bivalves and flora, separated one from another by 10 stratigraphic gaps, but the boundary between Devonian and Carboniferous has been considered as continuous. The limestone karstic geomorphology of the bay was developed since Miocene, especially the cone-shaped hills (fengcong), or isolated high limestone karst towers (fenglin) with many remnants of old phreatic caves, old karstic foot caves, marine notch caves form magnificent limestone karst landforms as unique on the world. The Quaternary geology was developed through 5 cycles with the intercalation of marine and continental environments. The present Hạ Long Bay, in fact, appeared after the Middle Holocene maximum transgression, leaving ultimate zone of lateral undercutting in the limestone cliffs bearing many shells of oysters, having the 14C age as 2280 to >40,000 y. BP. Geological resources are abundant: anthracite, lignite, oil shale, petroleum, phosphate, limestone and cement additives, kaolin, silica sand, dolomite, quartzite of exogenous origin, and antimony, mercury of hydrothermal origin. Besides, there still are surface water, groundwater and thermal mineral water on the shore of the Hạ Long - Bái Tử Long Bays and other environmental resources.

In terms of marine geology, this area is recorded as an especially coastal sedimentary environment. In the alkaline seawater environment, the chemical denudation process of calcium carbonate proceeds rapidly, creating wide, strangely shaped marine notches.

The bottom surface sediments are various from clay mud to sand, however, silty mud and clay mud are dominated in distribution. Especially, the carbonate materials originated from organisms make up from 60-65% sedimentary content. The surface sediments of coral reefs are mainly sand and pebbles of which the carbonate materials occupy for more than 90%. The intertidal zone sediments are various from clay mud to sand and gravel depending to distinguished sedimentary environments such as mangrove marshes, tidal flats, beaches etc. At the small beaches, but wonderfully beautiful, the sand sediments may be dominated quartz or carbonate materials.

The sediment layers of intertidal zone, the upper sea bed with a plain surface conserving ancient rivers, systems of caves and it's sediments, traces of ancient marine action forming distinctive notches, beaches and marine terraces, mangrove swamps are important evidence of geological events and processes taking place during Quaternary.

History of tectonics

Hạ Long Bay has experienced at least 500 million years in various geological states of orogeny, marine transgression and marine regression. During the Ordovician and Silurianperiods (500-410 million years ago), Hạ Long Bay was deep sea. During the Carboniferous and Permian periods (340-250 million years ago), Hạ Long Bay was at shallow sea level.

The dominated uplift movement of neotectonic and recent tectonic influenced deeply on topography of this area, and the present landscape of sea-islands was formed around 7 or 8 thousand years ago by the sea invasion during Holocene transgression begun at about 17-18 thousand years ago. Particularly from the Holocene time, from about 11,000 years ago Cat Ba - Hạ Long area has much archaeological evidence connecting variations in sea levels with the development of ancient cultures such as the Soi Nhu and Ha Long cultures.

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