| 词条 | Gruta do Carvão |
| 释义 |
| name = Gruta do Carvão | other_name = Monumento Natural Regional da Gruta do Carvão Regional Natural Monument of Gruta do Carvão | photo = Gruta Carvão.jpg | photo_width = 235px | photo_caption = A view of the visit area of the Gruta do Carvão | map = | map_width = 235px | map_caption = | location = São Miguel (Azores), Portugal | depth = | length = {{convert|1650|m|ft}} | height_variation = {{convert|6.4|m|ft}} | coordinates = {{coord|37|44|53.4|N|25|41|13.4|W|format=dms|display=inline}} | coords_ref = | survey = | survey_format = | discovery = | geology = Lava tube, Basalt | entrance_count = 1 | entrance_list = Rua do Paim | difficulty = | hazards = | access = Tours are available in season | language = Portuguese | features = Stalactites, Stalagmites }} The Gruta do Carvão (Grotto of Coal) is an ancient lava tube located on the outskirts of the municipality of Ponta Delgada (in the civil parish of Santa Clara) on the island of São Miguel in the Portuguese archipelago of the Azores. HistoryGaspar Frutuoso, the 16th century chronicler and historian wrote: "Afar, a short way from the Fortress, going west, is a place called Ponta dos Algares, because there are two grottos with their opening, inside which there is a large underground path where rivers of lava seeming to have run in ancient times, not known nor seen."[1] Owing to its scientific, educational and touristic relevance, as well as its natural characteristics, the Gruta do Carvão was classified as a Regional natural Monument by Regional Decree 4/2005/A on 11 May 2005.[1] GeographyThe Gruta is situated in the parish of Santa Clara, in the northwest part of Ponta Delgada and is integrated into the Monumento Natural Regional da Gruta do Carvão (Regional Natural Monument of Gruta do Carvão), to the northwest of water reservoirs of SMAS, along Rua do Paim.[1] The largest lava tunnel on the island of São Miguel, the cave is located in the western edge of Ponta Delgada and extends for {{convert|1650|m|ft}}. It is divided into three sections: Rua de Lisboa (or Secadores de Tabaco), Rua do Paim and Rua João do Rego. Yet, older documents and field work suggest that the tube actually longer, and may reach a length of {{convert|5|km|mi}}.[1] The section at Rua do Paim is approximately {{convert|557|m|ft}} long, with an internal cavity that is at its maximum extent {{convert|6.4|m|ft}} high and {{convert|8|m|ft}} wide.[1] Along the cavern walls are speleological structures such as lateral benches, lava bridges, branching galleries, lava balls, stalactites, stalagmites, columns, spongy lavas, glaze and tree moulds.[1] Apart from several cracks, the walls and ceiling are multi-coloured (orange to yellowish) due to the basalt oxidization. There are also conical-shaped stalactites, secondary mineral deposits of silica and earthen deposits covering the walls and ceiling.[1] Many of the stalagmites are {{convert|25|cm|in}} long with long sections of superimposed, soda-straw, conical ring-type tubes with pitted pockets.[1] See also
ReferencesNotes1. ^1 2 3 4 5 6 7 Amigos dos Açores (2015) Sources
4 : Ponta Delgada|Lava tubes|Caves of the Azores|Protected areas of Portugal |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。