Geology news

Interesting geology on the sea floor

At there is a piece on deep sea vents in the Caribbean - with a difference (published in Nature Communications, January 10th). The vents, or deep sea hot springs we might say, are 5km down in a rift on the Caribbean sea floor. What is novel however is the discovery of 'black smokers', which are vents too, on the upper slope of an undersea mountain which rises 3km from the sea bottom. The mountain formed, it is claimed, when a vast slab of rock was twisted up out of the ocean floor. How did that happen?

The Quasicrystal

A rock from a mineral collection donated to a museum in Florence has an origin in the Koryan mountains in the Kamchatka peninsular. It was recently found to include grains of icosahedrite, a quasicrystalline mineral that was first discovered in a laboratory, according to a paper in PNAS - see It is the inner structure of these minerals that is novel as rather than being clusters of atoms as in ordinary crystals their composition is much more intricate and can form strange shapes such as a 20 sided icosahedron - with the symmetry of a ball.

Do the Plates move around the globe, or is that an illusion?

The actual idea of continental drift has never been accepted - what we have in the consensus theory of Plate Tectonics is something more subtle. In this all the plates move but in different directions and at different speeds, and the plates consist of both continental crust as well as the attached sea floor bottom. In Wegener's theory it was just the continental crust that moved, and Africa, it was said, was formerly joined to South America and NW Europe to Newfoundland and the Appalachians.

New island(s)

We have already seen that an undersea volcano is in the process of creating a new island in the Atlantic - adding it to the Canaries, Now, a new island has emerged in the midst of another group of islands - in the Red Sea (see It was spotted by a NASA camera onboard an orbiting satellite (image included) and this too was formed from volcanic activity on the seabed - off the coast of Yemen.

Canaries volcano and a spaceship at the edge the solar system

The under-sea volcano that has erupted deep on the sea-bed off the Canary island of El Hierro is now just 60m below the surface - and still growing. It will either create a new island in the Atlantic or will become an extension of the southern shore of El Hierro. There is also seismic activity to the north of El Hierro and over the last 4 months there has been some 11,000 tremors across El Hierro itself (see

Bumping the Crust

At we learn that the Fukushima earthquake moved the sea floor as much as 50m laterally and 16m vertically. In addition, the crust as a whole did not move forwards by 50m but varied between the coastline and the nearby trench (thought to be a subduction zone) which means that closer to the coast it was just a movement of a few feet, and out at sea rising to 20 and 30m and even further out to 50m movement.

Compromise at K/T boundary

Geoscientist Gerta Keller is extraordinarily consistent and has been a long time critic of the asteroid strike that killed the dinosaurs - based on geological dating of the strata (see Now, somewhat of a compromise seems to have been reached - there was more than one asteroid strike, not at the same time, but separated by 100s of thousands of years. It is geochronology that has caused this compromise as sedimentary layers are assumed to have been laid down over long periods of time.

Loess ... coming from the wrong direction, and that sinking feeling

The consensus view is that loess, the fine grains of silt that have accumulated in different parts of the world but especially in great big dunes in China, is thought to be wind blown dust from the direction of the Arctic. In the case of China the loess was thought to have blown in from the north west, in the direction of Siberia and presumably the tundra. It seems this interpretation may be up for grabs. Not the theory of course but the origin of the loess.

A new island is forming in the Atlantic

News that the volcano growing on the seabed near the Canaries is about to break the surface of the sea is at (see also The initial eruption occurred at a depth of 2300 feet and the other at a depth of 655 feet (see also

Fossils in Amber

We all know about insects in amber, preserved as fossils and highly prized by our ancestors. The trade in Baltic amber during the past is well catalogued in archaeological studies. The entombed insects of Baltic amber go back to the Eocene. Amber comes from the resin of trees - but the species of tree has not been identified. What you might not know is that fossilised tree resin has been found all over the world and from different epochs in time - see the Deposits Magazine (Southwold in Suffolk) issue 26 (2011).