Geology news

Shale Oil and Gas

The existence of shale oil and gas in rocks of different periods must have an origin somewhere in the natural world - unless it is abiotic. At https://phys.org/print440145555.html ... we learn that a massive volcanic flare-up during the Cretaceous era was responsible for some of the deposits. Other deposits such as the Marcellus date to the Ordovician era. Why volcanoes became so active is another problem.

Diamonds are Deeper

William sent in this link - www.yahoo.com/tech/super-deep-diamond-discovery-sheds-light-inner-workin... ... a large diamond dug up in South Africa contains calcium silicate perovskite trapped inside - a mineral not found on the surface of the Earth, we are assured. It is however abundant in the lower Mantle, we are told, but how did it reach the crust? According to a paper in Nature the mineral is highly unstable - unless trapped in a very strong container such as the diamond in question.

Storm Emma

William sent in this link. I assume it will pop up elsewhere at some time but have not noticed it as yet - go to https://uk.yahoo.com/news/storm-emma-uncovers-ancient-7000-year-old-fore... ... storm Emma uncovered a fossil forest in shifting sands near Hartlepool. A stretch of sand 400m in length was peeled back to reveal the remains.

Not Written in Stone

Link provided by Robertus Maximus. It is the February 2018 newsletter of the AAPG (the Explorer). The piece is written by Keith James a consultant geologist and fellow of the Institute of Geophysics and Earth Sciences at Aberystywyth University in Wales. He has worked with Shell all over the world - and later with Conoco. The piece begins by saying that published Plate Tectonics (PT) teaching is complacent. It should adapt to emerging data, including multiple working hypotheses, and enable students to think.

Pileus

At http://spaceweather.com (March 2nd 2018) we have a fine image of saucer clouds over Brasilia ....

Red Beds

At https://sites.google.com/site/redbedsgeology/ ... red beds are composed of aeolian sands - sand waves deposited by flooding (or by tides). These also include sandstone rocks and can be seen on the Colorado Plateau - and various other places, dating from diverse geological periods. The oldest of them go back 1.5 billion years ago (the Proterozoic) and the youngest just 6 million years ago (the Miocene). They are  sand that has been reddened by finely dispersed iron oxides within clay minerals. They can actually be clay stones, silt stones, and conglomerates, and not just sandstone.

Mediterranean Mega Flood

This story is at https://phys.org/print438943372.html ... a study by an international team have found evidence of a mega flood during the Zanclean Period in which water from the Atlantic poured back into the Mediterranean basin and brought an end to the Messinian Salinity Crisis (5 million years ago). The study was led by Aaron Micallef of the University of Malta and is published in Scientific Reports journal (Feb 2018). The arguments revolve around bore hole data off Sicily, sediments buried in the sub surface characterised as chaotic.

Formation of Clays

At https://phys.org/print437125828.html ... in this instance, clay formation on the planet Mars. Temperature on Mars is well below freezing but it must once have been warmer if liquid water carved out features on the surface. Not only that but the water had to be warm enough for surface clays to form. The researchers opt for a series of short term warming episodes leading to temporary wet climates. All speculation of course.

Giant Earthquakes

At https://phys.org/print436523070.html ... giant earthquakes are not as random as thought. Analysis of sediment cores from lakes in Chile show that EQs reoccur at regular intervals. It is only when smaller EQs are added that the incidents show up randomly in time. A Chilean EQ in 1960 had a magnitude of 9.5 and produced a massive tsunami wave that pummeled the coastal regions and caused a wave that travelled right across the Pacific to kill 200 people in Japan. Strong EQs produce underwater landslides which are preserved in sedimentary layers.

Scottish Submerged Forest

This story is again interesting as far as changing sea levels and ocean configuration is concerned. At https://www.scotsman.com/lifestyle/archaeologists-survey-scotland-s-fore... ... archaeologists are surveying Scotland's submerged forests (rather, wooded regions under the waves). This seems to revolve around the Bay of Ireland in the Orkneys and Benbecula in the Outer Hebrides.