Milos 2007 — BUFI workshop report

The workshop was led by Dr Stephanos Kilias (University of Athens), and Drs Jon Naden and Mike Petterson (BGS). Drs Kilias and Naden are currently involved in research on Milos and Dr Petterson is currently researching the [similar] volcanic and hydrothermal processes in the Solomon Islands.

Students were asked to give a 10–15 minute presentation, as part of the networking exercise, on an aspect their research in a format accessible to all participants irrespective of the scientific backgrounds.

Comments and Milos photo Gallery.

Students and BGS staff said that the trip was a fulfilling experience that was an excellent opportunity to get to know one another. Those with backgrounds close to the scientific focus of the trip benefitted from the opportunity to examine the deposits first-hand, with the experts on-hand.

Scientific focus of the field trip

The primary focus of the field workshop was to examine the inter-relationships between volcanism and hydrothermal activity and the generation of economic mineral deposits including both metallic and industrial minerals. The students also had the opportunity to examine exciting geological features such as:

  • transition from submarine to sub-aerial volcanism, including submarine ignimbrites and the vent zone of an extinct volcano
  • an active shallow submarine geothermal system
  • interaction of biology and mineralisation. Milos has a several uniquely preserved fossil subaerial and submarine geothermal systems with their own unique flora and fauna.

Scientific focus of the field trip

The small archipelago of Milos is situated in the central part of the modern Southern Aegean Volcanic Arc (SAVA). These volcanic islands lie in an area of complex extensional and subduction-related tectonics. The SAVA is the surface expression of active, northward subduction of the African plate beneath the Aegean microplate. The arc is no more than 20 km wide, and stretches from Crommyonia in the west, through Methana, Aegina, Milos, Santorini, to Nisyros and Kos in the east.

Arc volcanism began at the end of the Early Pliocene and the arc volcanoes lie above a Benioff Zone at 130–150 km depth, and are about 200 km from the Hellenic Trench. Fault-plane solutions for earthquakes along the arc are normal in character Therefore, despite the compressive stress regime associated with subduction, the arc has developed in an extensional environment.

Milos island is the largest of four islands in the Milos archipelago. The neighbouring islands of Kimolos and Polyegos composed of submarine and subaerial, calcalkaline volcanic and submarine sedimentary rocks that are broadly similar to those on Milos. The volcanic rocks are predominantly rhyolite and dacite, with subordinate andesite and basaltic andesite.

The island of Antimilos is dominated by dacitic and andesitic lavas, and minor pyroclastic units, and is thought to represent the uppermost part of a polygenetic composite volcano.

The Milos volcanic succession occupies approximately 151 km2 and has a maximum thickness of 700 m. The succession is composed of calc-alkaline volcanic and sedimentary rocks. The volcanic rocks predominantly have rhyolitic and dacitic compositions; andesitic compositions are subordinate. The stratigraphy exposed on Milos shows an upward progression from submarine to subaerial depositional environments.

Contacts for further information

Dr Jon Naden
BGS University Funding Initiative
British Geological Survey
Keyworth
Nottingham
NG12 5GG
E-mail: BUFI
Telephone: 0115 936 3100
Fax: 0115 936 3200
Twitter: @DocBGS