Flores, along with the island of Corvo, is situated on the American Continental Plate of the Mid-Atlantic Ridge, and belongs to the western group of islands in the Azores archipelago. Geomorphologically, the island is composed of two units:
The Central Massif - it is the central plain, where is located many maar structures with lake-filled craters adjacent lands;
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The Coastal Periphery - it includes the coastal zones, cliffs and ancient beaches, as well as the coastal shelf. The island developed initially from a submarine volcano from the Pleistocene period that constructed small calderas and numerous pyroclastic cones. Following a long period of quiescence beginning about 200,000 years ago, several young phreatomagmatic craters and associated lava flows erupted during the Holocene period, including two about 3000 years ago.
The Funda de Lajes tuff ring formed about 3150 years ago, accompanied by a lava flow that traveled toward the southeast reach the area of Lajes. The Caldeira Comprida tuff ring in Caldeira Seca (west-central Flores) later, at about 2900 years ago, producing a lava flow that traveled towards the region of Fajã Grande.
Azevedo et al. (1986) divides the lavas and deposits into two major volcanic complexes:
Basal Volcanic Complex - includes products and deposits of both submarine and sub-aerial volcanism, formed by pyroclastic deposits and inter-bedded flows of alkali basalts.
Upper Volcanic Complex - represents the main sub-aerial activity composed of three main stratigraphic units, that include basaltic to trachytic flows with inter-bedded pyroclastic deposits in the first two layers, and a more recent unit of exclusively pyroclastic deposit |
The Ponta da Caveira is a classified geoplace for the Azores Archipelago as stated in the Azores Geopark.
It is a rocky promontory located near the Portuguese village of Caveira on the east coast of Flores Island, 1.5 nautical miles from the Port of Santa Cruz das Flores and 3.5 nautical miles from the port of Lajes das Flores, in Geographic coordinates of latitude 39 º 25,592 'North and Longitude 31 º 08,298' West.
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This promontory is characterized by a long spit of land that is drained into the sea formed by lava flows in different geological epochs forming several caves and crevices in the wall, caused by lava tubes of large dimensions. On the north side of this promontory named Ponta da Caveira, you find the Cave of Enxaréus, which is the largest cave on the island of Flores, with about 50 meters long and 25 wide.
The seabed in this zone, including funds from within the crevices and caves, is made mostly by pebble, boulders of sand and small clearings.
The dimension of depth is very variable, beginning at the foot of the rocky wall of the Ponta da Caveira geoplace, to the bottom, which is about 17 feet deep and to the east, along the rocky wall which increases in depth until a maximum of 25 meters. |
About the Earthcache:
Take the Road by car from Santa Cruz to Lajes and on Caveira village, park the car at N39 25.623 W31 08.501 that is a belvedere/viewpoint, then just start walking the trail way down into Ponta da Caveira ("tip of the skull").
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To log the cache you should:
a) answer the question: What is the name of the most famous cave bellow / north sided of the Ponta da Caveira promontory, that is about 50 feet long and 25 tall?
b) What is the deepest size of the Ponta da Caveira promontory?.
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c) By your own words, explain how this "spits of land"/landforms are formed
Being OPTIONAL, please take a photo in the local GZ coordinate with you and gps.
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