Published on Sep 24, 2013
Before it's news. Category:
Many thanks to Pedro Branco, Eduardo Costa, Viviana Lopes, Daniel Mendes, Jo Anne Taisbin and others who have messaged me to tell me about this. The name of the discoverer, featured in the video, is Diocleciano Silva. According to the video the discovery was made five months ago but there has been minimal international coverage up to now. Eduardo Costa and Daniel Mendes both sent me a link to this short article on the subject in English: http://
Looks like I might need to get my wetsuit on again! I wasn't planning any further diving research for the sequel to Fingerprints of the Gods but if this checks out I'm there! In general what we know about rising sea levels at the end of the last Ice Age (see my book Underworld for detail) tells us that lands now under 40 metres/130 feet of water were submerged more than 12,500 years ago
The volcano comprises several dominantly basaltic pre-caldera eruptions, a trachytic caldera-forming stage and a post-caldera stage consisting of alternating trachytic and basaltic eruptions. The post-caldera flank lavas are more primitive (>5 wt % MgO) than the pre-caldera lavas, implying extended fractional crystallization and longer crustal residence times for the pre-caldera, shield-building lavas. Thermobarometric estimates show that the ascending alkali basaltic magmas stagnated and crystallized at the crust–mantle boundary (∼15 km depth), whereas the more evolved magmas mainly fractionated in the upper crust (∼3 km depth). The caldera-forming eruption was triggered by a basaltic injection into a shallow trachytic magma chamber. Lavas from all stages follow a single, continuous liquid line of descent from alkali basalt to trachyte, although slight differences in incompatible element (e.g. Ba/Nb, La/Nb) and Sr isotope ratios imply some heterogeneity of the mantle source. Major and trace element data suggest similar partial melting processes throughout the evolution of the volcano. Slight geochemical differences between post- and pre-caldera stage lavas from the Sete Cidades volcanic system indicate a variation in the mantle source composition with time.
The current Azores islands are volcanoes built up in a series of eruptions mostly from 8 million years ago up until 750,000 years ago, with a more recent stage of erruptions lasting until 210,000 years ago
Stratigraphic observations of Moore (1990, 1991b) and our own field work (Figs 2 and 3) show that Sete Cidades developed through three major phases of volcanic activity: (1) a dominantly alkali basaltic, pre-caldera, shield-building phase; (2) a trachytic caldera-forming phase; and (3) a mainly trachytic, effusive, post-caldera phase associated with small basaltic flank eruptions (Figs 2 and 3).The pre-caldera stage appears to dominate the volcano evolution, covering a time span from >210 000 years and lasting until the caldera-forming eruptions, which comprise a sequence of explosive eruptions that occurred 36 000, 29 000 and 16 000 years ago (Pacheco et al., 2005). The post-caldera stage thus covers the shortest time-span in the volcano's evolution. Hence, the thicknesses and volumes of the three stages differ accordingly. The thickness of the subaerial pre-caldera stage deposits is estimated from coastal outcrops at Mosteiros and Ponta da Ferraria to be at least 200 m, covering an age range from 74 000 years (oldest unit at Ponta da Ferraria) to 36 000 years (first caldera-related eruption; Fig. 3). However, the maximum thickness of the pre-caldera stage is thought to be significantly larger, because most of the volcano's pre-caldera deposits are either submarine or were covered by younger eruptions. The stratigraphy of Sete Cidades shows several fractionation cycles from basaltic to trachytic compositions over the last 210 000 years (Moore, 1991b) of subaerial activity. For example, the upper stratigraphic section at the sea cliff of Ponta da Ferraria (Fig. 3) shows four changes from basaltic lava flows to trachytic pumice, suggesting that the volcano regularly erupted magmas of different compositions during the pre-caldera stage. The intermediate and evolved magmas erupted from Sete Cidades volcano show ∼11 changes between a basaltic to intermediate and an evolved composition in the last 16 000 years.I case that is all Greek to you, the oldest levels represented at the Azores are massive flows in all directions making low-domed islands, which frequently occurs in oceanic islands such as Hawaii, although such flows do occur in continental landmasses. The intermediate levels are made up of aerated tuffs which can look like pumice and characteristically form in eruptions above sea level. Lava flows of this type in the Azores are like the ones from Tertiary volcanoes in Europe and even in South America (*Andesites)
A more recent set of explosive eruptions in the Azores formed calderas (craters) and these typically occur from explosions above sea level. In the area around the Azores several of these calderas are now submerged to great depths below sea level. Some of the events which were dated at the Sete Citadaes volcano and mentioned in this article were dated at 36 000, 29 000 and 16 000 years ago (Pacheco et al., 2005). and that last date probably includes the same date as Graham Hancock's given date of 12,500 years ago, when other lavas from explosive eruptions are found all over the North Atlantic sea floor. Lava fragments from this event are thus dated from 16000 to 12000 years ago (actually less than that, the date was given as a maximum estimate), average 14000, and this roughly corresponds to the date of the end of the Clovis in the USA .Once again there is a general problem for ALL dates in this period owing to a sudden disequilibrium of atmospheric carbon levels.
On several of the Azores there is a Pleistocene/Holocene boundary eruption layer or Brecchia, which has been traditionally dated to 10000 years ago or just befdore. And there are interesting records of Holocene (Geologically Recent) levels, too: one article detailing dates for such events is at
So that there were significant eruptios in the Azores Islands (included as Island-building events for the islands in their current conformation) at about 7500BC, 6500BC, and 4000BC. More interestingly there was a major catastrophe during the Bronze Age with uncertain dating but presumably in the realm of 1100 to 1300 BC and presumably related to Historical events going on in the Mediterranean at the time (Movements of the Peoples of the Sea included) There is an indication of some activity equivalent to Classical Greece in age and then some later events during the Roman Empire up to the Dark Ages (detailed in the article). At this point I was more interested in the Bronze age dates.The second event is represented by a white (yellow when weathered) trachyte pumice fall deposit which, in places, overlies the mudflows containing fragments of the oldest pumice. At an exposure (Fig. 2A, profile b) where the three pumice events are preserved, one sample (FA14) from the paleosol fossilized by the second pumice gave an age of 9570 ± 350 BP. A fall deposit, in which pumice grades upwards from white to gray, represents a third trachytic eruption. A sample (FA15) from the paleosol underlying this deposit yielded an age of 6490 ± 200 BP.A white trachyte pumice deposit, usually weathered to an orange-yellowish color, containing syenite lithic blocks not found in previous pumice falls, characterizes the fourth pumice event. As the base of this deposit is not exposed, and the deposit did not contain any organic material for dating, we can say only that its age is in the interval limited by the age of the third pumice deposit (6940 ±200 BP) and the age, 3140 ± 100 BP, of a paleosol (FA18) underlying a thin pyroclastic surge deposit identified in a roadcut between the Caldeira road and Lomba dos Flamengos (Fig. 2A, profile d). Webelieve that an explosion breccia older than 3940 ± 50 BP (FA4-A1), exposed near the caldera rim (Fig. 2A, profile f), may be a correlate of this pumice fall event.The fifth pumice sequence includes several events associated with the deposition of at least five breccias, several phreatomagmatic pyroclasts, pumice flows and surges. Pumice fragments show a white and gray banding. Samples from paleosols underlying the first (second block in profile f, Fig.2A) of these explosion breccias (a proximal facies) and a pyroclastic surge deposit (distal facies-Fig. 2A, profile d) yielded equivalent ages, 3320 ± 90 BP (FA4-A2) and 3140 ± 100 BP (FA18),respectively, suggesting that both deposits represent the same eruption.A second undated volcanic breccia rests directly on the breccia dated at 3320 ± 90 BP (Fig. 2A, profile f). A paleosol (FA17) underlying an alluvial (or perhaps pyroclastic?) deposit, exposed at the roadcut between the Caldeira road and Lomba dos Flamengos, was dated at 2360 ± 70 BP, which may be equivalent to the undated breccia.
The rise of the islands during these eruptions is assumed to have gone up several thousand feet in cumulative altitude. (From another source). So we have great eruptions and great vertical movements up and down documented in the Azores in the Latest Pleistocene and early Holocene periods (See also Zhirov)