SUNKEN ISLAND FOUND, OFF TOBAGO ISLAND'S COAST

SUNKEN ISLAND FOUND, OFF TOBAGO ISLAND'S COAST

Three years ago dur­ing deep sea ex­plo­ration, a land mass be­lieved to be a sunken mag­mat­ic vol­canic is­land, was dis­cov­ered off the coast of To­ba­go.

Buried un­der 10,000 feet of sand and clay be­neath the seabed, the vol­canic is­land was dubbed To­ba­go's long lost sis­ter by geo­sci­en­tists.

This vol­canic is­land, which is about the size of To­ba­go, is one of T&T's won­ders which av­er­age cit­i­zens know noth­ing about.

In this se­ries, the Guardian will ex­plore some of the ge­o­log­i­cal won­ders of the is­lands, both on and off­shore, in­clud­ing our vol­ca­noes.

Se­nior geo­sci­en­tist at Touch­stone Ex­plo­ration Xavier Moo­nan, who has been work­ing on ex­plo­ration drilling prospects with­in the Or­toire Block (on­shore south­east­ern Trinidad), has done ex­ten­sive ge­o­log­i­cal re­search across T&T in­clud­ing our mud vol­ca­noes.

Hav­ing served as a mud­log­ging ge­ol­o­gist for Schlum­berg­er (Geoser­vices), an ex­plo­ration ge­ol­o­gist at Petrotrin and lat­er at Cen­tri­ca, Moo­nan was part of the team which dis­cov­ered T&T's on­ly salt­wa­ter vol­cano in 2017, lo­cat­ed 15 miles deep in the forests of Guayagua­yare.

At Moru­ga, the Marac vol­cano is known by vil­lagers as T&T's sec­ond pitch lake; the colour­ful Anglais Point mud vol­cano of Erin, which is flow­ing in­to the sea; as well as the pop­u­lar Pi­paro, Dig­i­ty and Dev­il's Wood­yard vol­ca­noes will all be ex­plored, along with many more.

The Dig­i­ty vol­cano is the on­ly one with a tall, dis­tinct con­i­cal shape.

The sto­ries sur­round­ing the his­toric erup­tions of Pi­paro vol­cano and the Dev­ils Wood­yard vol­ca­noes re­main part of T&T's unique folk­lore and these will be ex­plored as well.

The vol­ca­noes, Moo­nan be­lieves, are hid­den trea­sures which could bring for­eign ex­change to T&T if prop­er­ly mar­ket­ed as part of T&T's tourism thrust.

BURIED VOL­CANIC IS­LAND

Trinidad and To­ba­go are not vol­canic is­lands.

Un­like the is­lands of the East­ern Caribbean such as Grena­da, St Vin­cent, St Lu­cia, Mar­tinique, Do­mini­ca, Guade­loupe, Montser­rat, Nevis, St Kitts, St Eu­sta­tius and Sa­ba, T&T does not have live vol­canic cen­tres.

How­ev­er, Moo­nan said this does not mean that the is­lands do not have rare and fas­ci­nat­ing ge­o­log­i­cal for­ma­tions.

In an in­ter­view, Moo­nan said in 2016 the buried vol­canic is­land off the coast of Eng­lish­man's Bay in To­ba­go was dis­cov­ered by geo­sci­en­tists.

"A for­mer op­er­a­tor of the Block-22 and North Coast Ma­rine Area (NC­MA-4) pre­sent­ed a pa­per at the So­ci­ety of Pe­tro­le­um En­gi­neers T&T En­er­gy Con­fer­ence held at the Hy­att Re­gency in 2016 in which they were able to map and pos­i­tive­ly iden­ti­fy a buried, for­mer vol­canic is­land, the long lost sis­ter of To­ba­go," Moo­nan dis­closed.

He said the op­er­a­tor coined the is­land Is­la de la Asump­ción, af­ter one of the orig­i­nal names Christo­pher Colum­bus had for the is­land of To­ba­go.

"The an­cient is­land ba­si­cal­ly was pulled down­wards con­stant­ly over mil­lions of years and it is now buried be­neath 10,000 feet of sand and clay be­low the seabed.

The area con­tin­ues to move rel­a­tive­ly down­ward with re­spect to the To­ba­go north­ern coast, with the seabed in that area rang­ing be­tween 1,500 to 3,000 feet be­low sea lev­el, so the area is cur­rent­ly in very deep wa­ter," Moo­nan said.

He said about five mil­lion years ago the area was rel­a­tive­ly shal­low wa­ter and the tops of the vol­cano peaks, may have ap­peared as stacks just about to go be­low the wa­ter lev­el.

"About eight mil­lion years ago, Is­la de la Asump­ción oc­curred a mere 10km im­me­di­ate­ly north of To­ba­go.

The is­land shared many sim­i­lar­i­ties to that of To­ba­go.

It was ap­prox­i­mate­ly the same length, width, and ori­en­ta­tion, and its high­est moun­tain peaks are vir­tu­al­ly the same," Moo­nan said.

"Pi­geon Peak in Spey­side To­ba­go is lo­cat­ed on the north­east­ern part of the is­land and mea­sures some 550 me­tres.

Mt Karuna on Is­la de la Asump­ción is al­so lo­cat­ed on the north­east­ern part of the is­land and mea­sured some 524 me­tres above sea lev­el."

Through us­ing high-res­o­lu­tion 3D seis­mic da­ta, Moo­nan said maps were gen­er­at­ed on the top of the vol­canic rocks or base­ment.

"These rocks are very sim­i­lar in na­ture to those on­shore To­ba­go, and are cur­rent­ly buried be­neath 10,000 feet of sed­i­ment be­low the seabed.

Up­on close ex­am­i­na­tion, this map re­vealed strong ev­i­dence of den­drit­ic drainage—a tell­tale sign of river­ine ero­sion," he said.

So what hap­pened to Is­la del la Asump­ción and why did she sink be­neath the waves?

Moo­nan said earth­quakes and by ex­ten­sion, move­ment along the North To­ba­go Fault over the last 8 mil­lion years have re­sult­ed in the drown­ing and sub­se­quent bur­ial of Is­la de la Asump­cion.

"So just imag­ine that if you were able to be on Eng­lish­man's Bay some 8 mil­lion years ago, star­ing off­shore you would not have been able to see Grena­da, be­cause an is­land as big as To­ba­go it­self lay right in front of you," he said.