AAPG/GSTT HEDBERG CONFERENCE
“Mobile Shale Basins – Genesis, Evolution and Hydrocarbon Systems”
Mud volcanoes in the mobile shale basin of the
Consultant Geologist, International Geological
The Trinidad –
Subsequent classic work by Wall
& Sawkins in 1960 set the tone for a better understanding of mud volcanoes
when he studied in detail four (4) mud volcanoes in south
This was followed by an excellent report by Cunningham – Craig in 1902 which influenced prospectors into concentrating their exploration efforts in areas with oil seepages and gas shows with the hope that there was some connection between subsurface hydrocarbon accumulations and mud volcanoes.
In the following years, mud
volcanoes have been mapped by many researchers including Anderson (1911), Weeks
(1929), Maerky (1931), Kugler (1932 & 1968) and Wilson and Birchwood
(1965). A study by George Higgins and
John Saunders (1967) outlined the distribution of the mud volcanoes in the
The mud volcanoes of the Trinidad
– Eastern Venezuela area were formed within a mobile shale basin which extends
Mud volcanoes have erupted in the marine environment forming small islands which were shortlived due to wave action. Onshore, the volcanoes are present in more than twenty seven (27)
sites which are all linked in
some way to thrust fault and wrench fault systems which tap into the pressured
mobile shales. These volcanoes are not generally associated with the presence
of hydrocarbon accumulations although a few are present within the oil fields.
A Mud diapir in the Forest Reserve Field is documented as an intrusive event.
Similar situations are probably present in Main Field and
The seal at Piparo was removed by a landslide caused by abnormal excessive rainfall which caused down slope slippage of four (4) feet which was enough to shift the mud cap seal. The result was an eruption of mud and gas and water up to 100 feet in the air and deposition of mud over an area of 14 acres.
There was considerable damage to houses accompanied by loss of livestock and property. The road has since been abandoned and the area of the last mudflow is now inhabitable. The mud volcano at Piparo is now quiet with passive emissions of gas and water. We may not be able to accurately predict the next eruption but we know now what signs to look for. This eruption was a classic example of the movement of shale in a mobile basin.
AAPG Search and Discovery Article #90057©2006 AAPG/GSTT Hedberg Conference, Port of Spain, Trinidad & Tobago