Explore Geology
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Virgin Islands

National Park


cover of park brochure

park geology subheading
sailboat on the water
Virgin Islands National Park

Coral Reefs and Canopied Islands
Clear tropical seas, colorful coral reefs, white sand beaches, and the remains of centuries-old sugar plantations—these in combination with warm breezes and a relaxed way of living are the qualities that comprise the Virgin Islands. On St. John, the smallest of the three major U.S. islands, Virgin Islands National Park preserves the best of these qualities.

Growing from the rock outcrops bordering numerous bays and from small rocky cays (islands) are the coral reefs. These fringing reefs are a complex community of interacting marine plants and animals. The basic building blocks of reefs are hard corals— including:

  • brain,
  • elkhorn,
  • star,
  • finger, and
  • staghorn—and
  • soft corals (gorgonians)—especially sea fans and sea whips.
With the corals are a variety of fishes, including parrot, surgeon, angel fishes, grunts, and snappers.

Closely dependent upon the reefs are the sand beaches for which these islands are so well known. Without the growth of the living coral that comprises the reefs, the beaches could not exist, for the sand here is composed of minute fragments of coral. The reefs also protect the beaches from being washed away by winter ground seas (distant storm-generated waves). A relationship has been established here that is enduring but delicate, for the reefs, and in turn the beaches, depend upon close tolerances. The sea must be clear and pollution free, its salinity must stay within close limits (30-36 parts per thousand), and its temperature must always stay between 21° and 27°C (70° and 80°F).

Plant and animal life on these islands have been altered drastically by man.

  • At higher elevations, in protected valleys, and on northern slopes is the subtropical moist forest, the most extensive forest type on the island of St. John. This forest was cleared for raising sugarcane, but is now returning vigorously.

  • The lower elevations, southern and eastern slopes, and less-exposed coastal sites are primarily subtropical dry forests.

  • Along the southern and eastern shore, continuous easterly trade winds and direct exposure to the sun have created a more desert-like landscape in which dildo, opuntia, and turks head cactus may be present.

Indians, Pirates, and Planters
Man has been an inhabitant of these islands for centuries. Long before the birth of Christ, seafaring men using stone tools and bone implements hacked logs into canoes, swam, and fished in the clear waters of the Virgin Islands. Later, tribes of tall black-haired people from South America—farmers, pottery makers, warriors, and rock carvers—drifted with the winds and current through the curving necklace of islands now called the Lesser Antilles.

By the 2nd century A.D., peaceful Arawak villagers were living at Coral Bay, Cruz Bay, and Cinnamon Bay on St. John. In time, seafaring Carib people ranging up through the island chain took their toll of the Arawaks and established scattered outposts in the Virgin Islands. In turn, the Caribs nearly became extinct as European explorers and colonizers appeared in the Caribbean during the 16th and 17th centuries.

On November 4, 1493, Christopher Columbus, with a fleet of 17 ships, discovered the Lesser Antilles. By mid-November he had found an island he named Santa Cruz or St. Croix. A few leagues northward the Italian explorer then charted a chain of green, mountainous islands that he christened Las Once Mille Virgines—the Virgin Islands. The Spanish claims resulting from Columbus' voyages began two centuries of international wars for supremacy of the West Indies.

Against this background, the island of St. John slowly awakened to the visits of occasional freebooters, run-away slaves, castaways, and Dutch timber cutters. In 1717, Denmark took control, initiating a period of prosperity during which slave labor built many sugar and cotton plantations. With the abolition of slavery in 1848, St. John gradually reverted to its former quiet existence.

On March 31,1917, the United States purchased the Virgin Islands from Denmark. The U.S. Navy managed the islands until 1931, when the Territory of the Virgin Islands was created. The Territory is administered by the the U.S. Department of the Interior. As a result of Congressional legislation and the donation of lands to the Government by Laurance S. Rockefeller and the Jackson Hole Preserve Corporation, Virgin Islands National Park was established on December 1,1956.

Points of Interest

  1. Cruz Bay, the administrative seat of St. John, has a few food stores and gift shops. Stop at the park headquarters and visitor center there for park orientation and publications.

  2. Trunk Bay has one of the best beaches in the world and offers an underwater nature trail for snorkelers. Lifeguards are on duty daily from 9 am to 4 pm. Facilities include changing rooms, toilets, pay telephones, a picnic area, and snack bar.

  3. Cinnamon Bay, the location of Cinnamon Bay Camp, has a camp store and cafeteria. Lifeguard services are provided from 9 am to 4 pm daily. A 1.6-kilometer (1-mile) self-guiding nature trail is located across from the camp entrance.

  4. The Leinster Bay area contains
    • a mangrove swamp,
    • reef flat, and
    • the partially restored ruins of the Annaberg sugar mill factory complex.
    From seaward, this complex, located above Leinster Bay on St John's rugged north shore, is reminiscent of an ancient European castle. The beautiful, thick-walled old buildings, constructed of cleverly fitted stone, native coral, and yellow and red Danish ballast brick, were familiar to the 18th and early 19th century Danes, Dutchmen, and slaves who toiled here. Under the hot Caribbean sun they worked endlessly to produce crude brown sugar, rich dark molasses. and strong rum for export to North America and Europe.

  5. Coral Bay, the site of the first established sugar plantation on St. John, was first settled in 1717. The site was selected because of its well-protected harbor.

  6. Salt Pond Bay and nearby Lameshur Bay are generally calm during the winter ground seas that make snorkeling and swimming hazardous on the North Shore beaches. A side trail leads to a salt pond, then to the rugged, wind-swept, coral rubble beach at Drunk Bay. Another trail winds through a growth of barrel cactus called turk's head to Ram Head, with its magnificent views of St. John's southshore and the British Virgin Islands.
    WARNING. Ram Head has a steep cliff. Do not approach the edge. Keep children under control.

  7. Four-wheel drive vehicles are required for the drive to Lameshur Bay. A picnic area, toilets, ranger station, and research station are located in this area, once known for its bay oil, lime juice, and cattle production. Several interesting hiking trails connect Lameshur Bay with Reef Bay, Europa Bay, Yawzi Point, and the Bordeaux Mountain Road.

  8. Reef Bay Valley contains mysterious petroglyphs (rock carvings), some of which are attributed to West African origin and others to Taino Indians. Also within the valley are ruins of the Reef Bay Estate house and steampowered sugar mill ruins, the last to operate on the island.

    Reef Bay is accessible from Centerline Road by a shady, 5-kilometer (2.6-mile) downhill hiking trail that traverses a unique subtropical moist forest to dry forest area of St. John. Toilets and litter barrels are conveniently located at the end of the Reef Bay Trail.

Virgin Islands National Park The park is located on St. John, the smallest of the three major U S Virgin Islands, and includes most of the islands just offshore.

As the Nation's principal conservation agency, the Department of the Interior has responsibility for most of our nationally owned public lands and natural resources. This includes fostering the wisest use of our land and water resources, protecting our fish and wildlife, preserving the environmental and cultural values of our national parks and historical places, and providing for the enjoyment of life through outdoor recreation. The Department assesses our energy and mineral resources and works to assure that their development is in the best interests of all our people. The Department also has a major reponsibility for American Indian reservation communities and for people who live in Island Territories under U.S. administration.

park maps subheading

The General park map handed out at the visitor center is available on the park's map webpage.

For information about topographic maps, geologic maps, and geologic data sets, please see the geologic maps page.

photo album subheading

A geology photo album for this park can be found here.

For information on other photo collections featuring National Park geology, please see the Image Sources page.

books, videos, cds subheading

Currently, we do not have a listing for a park-specific geoscience book. The park's geology may be described in regional or state geology texts.

Please visit the Geology Books and Media webpage for additional sources such as text books, theme books, CD ROMs, and technical reports.

Parks and Plates: The Geology of Our National Parks, Monuments & Seashores.
Lillie, Robert J., 2005.
W.W. Norton and Company.
ISBN 0-393-92407-6
9" x 10.75", paperback, 550 pages, full color throughout

The spectacular geology in our national parks provides the answers to many questions about the Earth. The answers can be appreciated through plate tectonics, an exciting way to understand the ongoing natural processes that sculpt our landscape. Parks and Plates is a visual and scientific voyage of discovery!

Ordering from your National Park Cooperative Associations' bookstores helps to support programs in the parks. Please visit the bookstore locator for park books and much more.

geologic research subheading

In July 1997, marine biologists at the U.S. Geological Survey Field Station on St. John observed a new, apparently virulent and rapidly advancing coral disease on a number of coral reefs. Since then, follow-up by the scientists has included monitoring the spread of the disease and the fate of the infected coral heads. Ongoing research about this disease is a part of the Coral Reef Monitoring Program being conducted by scientists at the field station on St. John, and is one of the longest-running coral reef monitoring programs for the Atlantic/Caribbean.

Information about the park's research program is available on the park's research webpage.

For information about permits that are required for conducting geologic research activities in National Parks, see the Permits Information page.

The NPS maintains a searchable data base of research needs that have been identified by parks.

A bibliography of geologic references is being prepared for each park through the Geologic Resources Evaluation Program (GRE). Please see the GRE website for more information and contacts.

selected links subheading

NPS Geology and Soils Partners

NRCS logoAssociation of American State Geologists
NRCS logoGeological Society of America
NRCS logoNatural Resource Conservation Service - Soils
USGS logo U.S. Geological Survey

teacher feature subheading

Currently, we do not have a listing for any park-specific geology education programs or activities.

For resources and information on teaching geology using National Park examples, see the Students & Teachers pages.
updated on 01/04/2005  I   http://www.nature.nps.gov/geology/parks/viis/index.cfm   I  Email: Webmaster
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