An ancient volcanic chain of islands known as the  Lesser Antilles Click to see the chain.

Montserrat

Plymouth, the former capital city and major port of Montserrat, July 12, 1997, after pyroclastic flows had burned much of what was not covered in ash. 

 

The Soufrière Hills volcano (French "Sulphur" Hills) is an active complex stratovolcano with many lava domes forming its summit on the Caribbean island of Montserrat. After a long period of dormancy it became active in 1995, and has continued to erupt ever since.

    Main article: Geography of Saint Lucia

The volcanic island of Saint Lucia is more mountainous than many other Caribbean islands, with the highest point being Mount Gimie, at 950 metres (3,120 ft) above sea level. Two other mountains, the Pitons, form the island's most famous landmark. They are located between Soufrière and Choiseul on the western side of the island. Saint Lucia is also one of the few islands in the world that boasts a drive-in volcano.

 
Mount Scenery,  Saba.  The Netherlands Antilles.

Mount Scenery is a lava dome which forms the summit of the Saba island stratovolcano. At an elevation of 877 m.  The Saba volcano is potentially dangerous; the latest eruption was in or around the year 1640 and included explosions and pyroclastic flows. 

Stratovolcano    Rhyolite  Obsidian Scource

Map of Grenada

The island Grenada itself is the largest island; smaller Grenadines are Carriacou, Petit Martinique, Ronde Island, Caille Island, Diamond Island, Large Island, Saline Island and Frigate Island. The islands are of volcanic origin with extremely rich soil. Grenada’s interior is very mountainous with Mount St. Catherine being the highest at 2,756 feet (840 m).

Martinique

The north of the island is mountainous and lushly forested. It features 4 ensembles of pitons and mornes: the Piton Conil on the extreme North, which dominates the Dominica Channel, the Mount Pelee, an active volcano, the Morne Jacob, and the Pitons du Carbet, an ensemble of 5 rainforest-covered extinct volcanoes dominating the Bay of Fort de France at 1,196 meters. The most dominating of the island's many mountains, with 1397 meters, is the infamous volcano Mount Pelée. The volcanic ash has created grey and black sand beaches in the north (in particular between Anse Ceron and Anse des Gallets), contrasting markedly from the white 

Mount Pelée  The volcano is now famous for its extremely destructive eruption in 1902 and the destruction that resulted, now dubbed the worst volcanic disaster of the 20th century.[1][2] The eruption killed about 30,121 people,[3][4] most deaths in the destroyed Saint-Pierre, at that time the largest city in Martinique, due to its deadly pyroclastic flows.[5]

  1. ^ Wright, Pierson (1992). USGS Circular 1073. USGS. pp. 39. 
  2. ^ Tilling (1985). Volcanoes. USGS. p. 16-17. 
  3. ^ "USGS document of the 1902 eruption of Mount Pelee". USGS. http://vulcan.wr.usgs.gov/Volcanoes/WestIndies/Pelee/description_mont_pelee.html. 
  4. ^ Tilling (1985). Volcanoes. USGS. 
  5. ^ Blong, R.J. (1984). Volcanic Hazards: A Sourcebook on the Effects of Eruptions. Orlando, Florida: Academic Press. 

Saint Vincent is a volcanic island in the Caribbean, the largest island of the chain called Saint Vincent and the Grenadines. It is located in the Caribbean Sea, between Saint Lucia and Grenada. It is composed of partially submerged volcanic mountains.   La Soufrière is still an active volcano . [1]

 [1] ^ Rogozinski, Jan (1999). A Brief History of the Caribbean (Revised ed.). New York: Facts on File, Inc.. pp. 358–359. ISBN 0-8160-3811-2.

St. Kitts is six miles (10 km) away from Saint Eustatius to the north and two miles (3 km) from Nevis to the south. St. Kitts has three distinct groups of volcanic peaks: the North West or Mount Misery Range; the Middle or Verchilds Range and the South East or Olivees Range. The highest peak is Mount Liamuiga, formerly Mount Misery, a dormant volcano some 3,792 feet (1,156 m) high.

 



Click above.

THE SOURCE OF PUMICE FOUND AT PREHISTORIC ARCHAEOLOGICAL SITES IN FLORIDA – PETROGRAPHIC AND GEOCHEMICAL EVIDENCE  http://gsa.confex.com/gsa/2006SE/finalprogram/abstract_102291.htm   


V53A MCC:level 1 Friday 1340h

Rates and Timescales of Magmatic Processes III Posters

Presiding:A J Pietruszka, San Diego State University; J Grocott, Kingston University

V53A-0601 1340h

Time Evolution of the Basse Terre Island (Guadeloupe, French West Indies) Effusive Volcanism from New K-Ar Cassignol-Gillot Ages.

* SAMPER, A (samper@geol.u-psud.fr) , Geochronologie UPS-IPGP, Sciences de la Terre, Universite Paris-Sud, batiment 504, Orsay, 91405 France, Metropolitan
QUIDELLEUR, X , Geochronologie UPS-IPGP, Sciences de la Terre, Universite Paris-Sud, batiment 504, Orsay, 91405 France, Metropolitan
QUIDELLEUR, X , Paleomagnetisme, IPGP, Tour 14, 4 place Jussieu, Paris, 75252 France, Metropolitan
MOLLEX, D , Geochronologie UPS-IPGP, Sciences de la Terre, Universite Paris-Sud, batiment 504, Orsay, 91405 France, Metropolitan
KOMOROWSKI, J C , Geochimie et Volcanologie et Observatoires volcanologiques, IPGP, Tour 46, 4 place Jussieu, Paris, 75252 France, Metropolitan
BOUDON, G , Geochimie et Volcanologie et Observatoires volcanologiques, IPGP, Tour 46, 4 place Jussieu, Paris, 75252 France, Metropolitan

Radiometric dating and geochemistry of effusive volcanics have been combined with geomorphological observations in order to provide a general evolution model of the volcanic island of Basse Terre, Guadeloupe (French West Indies). More than forty new Cassignol-Gillot K-Ar ages distributed within the entire island, together with the twenty ages (Blanc, 1983; Carlut et al., 2000) previously obtained with the same technique, makes the Guadeloupe Island the best place to study the evolution of volcanic processes within the Lesser Antilles Arc. Dating was performed on the carefully separated groundmass in order to avoid K loss due to weathering and excess argon carried by mafic minerals. Ages obtained are relatively younger than previously thought on Basse Terre and range from a few ka to 2.79+-0.04 Ma. When available, the paleomagnetic polarity of the dated flows agree with the GPTS and a very good coherence of ages is observed for each massif. Our results demonstrate the general north to south migration of volcanism through time. It correlates with the main volcanic stages previously identified. The 2.75 Ma Basal Complex, the 1.81+-0.03 \_ 1.15+-0.02 Ma Septentrional Chain, the 1.02+-0.02 Ma \_ 0.606+-0.02 Ma Axial Chain, the 442+-6 \_ 207+-28 ka Mateliane \_ Sans Toucher Complex and the $<$ 200 ka Complex of La Grande Decouverte, which outlines a relative continuity in the Basse Terre magmatism. Lavas are mainly basaltic andesites and andesites although a few basalt and dacite have also been dated. All of them are characterized by low MgO values ($<$ 6 %), tholeiitic to calc-alkaline REE chondrite-normalized patterns and are of both low K and medium K affinity. Lavas display geochemical characteristics similar to that of the central islands of the Lesser Antilles arc. Within Basse Terre, geochemical characteristics are relatively constant through time, indicating no major change of volcanic processes during the whole subaerial activity. Finally the detailed chronological framework now available provides new constraints for estimating rates of edification and destruction at the island scale and, more generally, to help better understand the evolution of the still active Guadeloupe island Soufriere volcano.

 

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