Geology news

The volcano that blew 74,000 years ago

At ... acidity spikes in Greenland and Antarctic ice cores, calculated to date back to around 74,000 years ago, are thought to mark the eruption of a supervolcano, Toba in Sumatra. A paper in the journal Climate of the Past claims the eruption left a crater 50km in diameter and when it blew it expelled lava to the equivalent of two volumes of Mount Everest. The eruption, it is claimed, was 5000 times bigger and more violent than Mount St Helens which erupted in the 1980s.

Modelling the Younger Dryas

At ... we learn that computer modelling has been used to show the Younger Dryas event was caused by fresh water melt of the Laurentide ice sheet.

Leroy's Mischief

Leroy Ellenberger's latest piece of rhetoric in his fued with Thunderbolts personnel, sent to multiple email addressees (he collects them like discarded tram or train tickets), includes some interesting, and perhaps important, points of argument. Points that impact on uniformitarianism. Sean Mewhinney's article, 'Ice Cores and Common Sense' (which is often quoted by Leroy) was published by Marvin Luckerman and can be found on the Catastrophism CD (see the SIS Book Service).

NASA Rover Curiosity update

At ... an analysis fo soil on Mars by NASAs Curiosity Rover has revealed the presence of feldspar, pyroxenes and olivine, mixed with amorphous non-crystalline material. It was taken from a wind blown deposit (solar wind?) within a large crater and it has already been compared to volcanic soils on Hawaii. A compact X-ray diffraction instrument was fitted inside the Rover and is proving to be invaluable. This is the first of many soil and rock studies that Curiosity will produce.

Strike and Slip earthquakes

Two major strike and slip earthquakes struck off the coast of Sumatra in April (2012) - see ... and they are thought to have triggered a succession of earthquakes in various other spots around the world. The consensus view, that strike and slip earthquakes only occur at plate boundaries, has been modified. It is now being said a new plate boundary is in the process of being made, and the Indo-Australian plate is starting to separate.

Red clay on Bermuda

At ... is an interesting snippet of information from a paper in the Journal of Geophysical Research (doi:10.1029/2012JF002366) and this is that red iron rich clayer soil is found on Bermuda - but the origin is a mystery. The soil overlies carbonate rocks and it is possible dissolution of the carbonate rocks helped produce the clay beds. However, Bermuda sits in a position that might have been affected by the Mississippi river system, bringing down soil from inner North America.

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.