Geology news

Another collision with Earth

It's getting fashionable to hypothesize about meteor, asteroid or comet impacts. At ... a new study is claiming a cosmic body plunged into the southern ocean and generated a massive tsunami wave that plunged the world into the Ice Ages. See also which has lots of diagrams and maps. The paper on the subject will be in the forthcoming Journal of Quaternary Science - but I can already see problems that dissenters might pick up.

Dead Sea sediment core - some initial results are trickling through

The Dead Sea sediment core project is beginning to throw up some interesting data - see ... or ... pollen analysis at different levels of the core reveal some rapid changes from moist conditions to a dry environment. These occurred way back in the Neolithic, at 7500 years ago. However, something similar happened at the end of the LB age, around 3200 years ago.

Ice Age holding up sinking Venice

Venice is built on a former lagoon. That means a lot of silt and mud which is why it is sinking. However, according to The Times there is something holding it back, stopping it from being a disaster. An older layer of soil dating back to the Ice Age, beneath all the soft and smelly stuff. This is keeping the city above the waters. It has become a stone, or sorts, known as caranto, a calcium rich paleosol which covered most of northern Italy during the last Glacial Maximum. It is also composed of downwash from the Alps and its foothills.

Sea Level on Pacific Atolls

The journal Geology, August 2012, doi:10.1130/G33344.1 (see ... over the last 5000 years, or since 3000BC, sea levels have been within 0.25m of its present position, in the mid Pacific. This precludes global sea level oscillations of one or more metres from less stable locations. The mid Pacific atolls are tectonically stable and far from former ice sheets.

Plate Tectonics on Mars

This is a story which will run - see ... a Chinese scientists, An Yin, analysing images from the THEMIS spacecraft and the HIRISE camera on NASAs Mars Reconnaisance Orbiter, says he has found evidence of plate tectonics on Mars. This appears to involve fault lines, deep canyons, steep sided cliffs, and a linear volcanic zone.

Estimating the Ice Ages

At ... in spite of the claim one wonders if it is really the right title. It begins on the assumption the consensus model based on Milankovitch is right - which might not please everyone. However, it has a few revealing comments, the sort of thing you won't generally come across in textbooks. That is that the ratio of oxygen isotopes (oxygen 18 to oxygen 16) as preserved in fossil foraminifera shells in ocean sediments, is compromised.

Underwater Volcano

At ... an underwater volcano 600 miles offshore of New Zealand has erupted and there is a huge cluster of white pumice floating on the ocean surface, covering an estimated 26,000 square km of the surface.

The Changing Geoid and the Dinosaurs

At ... have a look at the two maps here and see what you think. Large parts of North America was underwater - as large parts of Europe. However, parts of the world now submerged were above sea level at the same time. Is this evidence of a changing geoid - or global warming?

Earthquakes, a Rift valley, and long times ago

At ... research into the Alpine fault on New Zealand's 'South Island' following on from the Christchurch earthquake, has discovered big ones occur roughly at 330 year intervals. The study is published in the journal Science. Such earthquakes have been happening on a regular basis for at least 8000 years.

The strange role of fungi in the demise of coal formation

At ... is a strange article but that might be as a result this site is about archaeology and the subject matter is geology - the coal seams of the world. It begins by saying that 300 million years ago the Earth suddenly interrupted its massive production of coal.