Saturday, 28 March 2015

Preservation of cellular structures in a fossil Sponge from the Middle Ediacaran of Guizhou Province, China.


Sponges are considered to be the sister group to all other groups of Animals, which is to say all other animals are more closely related to one-another than they are to Sponges and all Sponges are more closely related to one-another than to other Animals, but Sponges and other Animals are more closely related to one-another than they are to anything else. Phylogenetic studies have suggested that the common ancestor of Sponges and other Animals lived in the deep Cryogenian (the geological period that lasted from 850 to 635 million years ago) and a number of putative Sponge fossils have been found from the Cryogenian and Ediacaran (635-540 million years ago), which tends to support this hypothesis. However the simple organization of Sponge bodies, which lack specific tissues and can reform if squeezed through a sieve, makes it very hard to determine if these putative Sponges are true members of the group, or ‘Sponge-grade organisms’, which may be ancestral to Sponges, other Animals, both or neither.

In a paper published in the Proceedings of the National Academy of Sciences of the United States of America on 9 March 2015, Zongjun Yin and Maoyan Zhu of the State Key Laboratory of Palaeobiology and Stratigraphy of the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences, Eric Davidson of the Division of Biology at the California Institute of Technology, David Bottjer of the Department of Earth Sciences at the University of Southern California, Fangchen Zhao, also of the State Key Laboratory of Palaeobiology and Stratigraphy of the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences, and Paul Tafforeau of the European Synchrotron Radiation Facility describe a Sponge-like fossil from the Doushantuo Formation of Guizhou Province, China.

The Doushantuo Formation outcrops across much of South China, and has produced a large number of spectacular microfossils showing a remarkable level of cellular preservation, including fossils interpreted as possible embryos, dating from between 635 and 551 million years ago. Unlike other fossil sites producing such remarkable levels of preservation, it is interpreted as having formed in a high-energy, wave dominated environment, which led to the preservation of small biological particles in phosphatised granules, but not the preservation of larger structures such as body fossils of non-microscopic Animals. The possible Sponge comes from a gray oolitic dolomitic phosphorite layer exposed at the Badoushan Phosphorite Mining Quarry in Weng’an County in Central Guizhou, which is interpreted to be about 600 million years old.

The fossil is named Eocyathispongia qiania, where ‘Eocyathispongia’ means ‘Dawn-cup-shaped-Sponge’ and ‘qiania’ is a term for Guizhou Province. It is approximately 1.2 mm by 1.1 mm, and comprises three cup-shaped tubes emerging from a common base. These tubes have numerous pore-like openings, which if this organism was biologically similar to a modern Sponge would be inflow channels through which the filter-feeding Animal drew water prior to expelling it through the larger openings at the end of each tube. The outer surface of the fossil is covered by flattened cells 8–12 μm in diameter; these are split into two classes, with oval cells being consistently larger than circular ones, implying that cellular differentiation was present (something found in all Animals, including Sponges, but not usually in colonies of single-celled organisms).

Scanning electron micrograph of Eocyathispongia qiania showing the main tubular chamber with a large opening and additional chambers viewed from the exterior. Yin et al. (2015).

Based upon the available data, Yin et al. interpret Eocyathispongia qiania as being a genuine Sponge, albeit one that lived prior to the differentiation of the group into its modern orders. The cellular structure of the fossil resembles modern Sponges, though it does not show preserved choanocyte cells (flagella bearing cells which drive the movement of water through the Sponge) would be the best indicator of a true Sponge, it does have a structure that would be difficult to interpret in any other way, and dates from approximately the same time as the earliest Doushantuo specimens interpreted as Cnidarians (the group that includes modern Jellyfish, Corals and Sea Anemones) and Bilaterians (all animals other than Sponges, Cnidarians and Ctenaphores – Comb Jellies).

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An enigmatic animal from the Australian continental shelf, with possible similarities to some members of the Ediacaran Fauna.

The Ediacaran Fauna comprises a group of fossils from the Late Ediacaran Period, found at sites around the world and pre-dating the Cambrian Explosion, which is considered to indicate the origin of the majority of modern animal groups, and in particular those with mineralized skeletons. Some biologists have suggested that these organisms represent an entirely separate experiment...


The fossils of the Ediacaran Period record the first widespread macrofossils in the rock-record. Many of these fossils do not appear to belong to any modern group, but instead are thought to belong to an extinct taxa (sometimes known as ‘Vendobionts’), which may-or-may-not be related to modern Animals, though some fossils have been linked to Sponges (a group which also has...



Sponges are curious creatures. They are considered to be animals as they are multicellular and some of them have fixed body shapes, however they show no cell differentiation, and can be broken down into individual cells (by, for example, forcing them through a sieve) and they will re-assemble themselves without apparent...



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Magnitude 4.7 Earthquake off the south coast of the Dominican Republic.

The United States Geological Survey recorded a Magnitude 4.7 Earthquake at a depth of 20.8 km off the south coast of the Dominican Republic, slightly before 2.15 pm local time (slightly before 6.15 pm GMT) on Friday 27 March 2015. There are no reports of any damage or injuries associated with this event, but people have reported feeling it across the central part of Hispaniola (the island upon which Haiti and the Dominican Republic sit).

The approximate location of the 27 March 2015 Dominican Republic Earthquake. Google Maps.

The Dominican Republic forms the eastern part of the island of La Hispaniola, in the Greater Antilles.  The island has a complex geological structure, with parts of it lying on three different tectonic plates, and two plate margins running east-to-west across the island. The northernmost part of the island lies on the North American Plate. This is divided from the Gonâve Microplate by the Septentrional Fault Zone, which runs through Rio San Juan, along the north coast of the Dominican Republic and Haiti, then across the Windward Passage and along the south coast of Cuba. The Gonâve Microplate is moving east relative to the North American Plate, pushed by the Mid-Cayman Spreading centre to the west of Jamaica. To the south the Gonâve Microplate is separated from the Caribbean Plate by the Enriquilo-Plantain Garden Fault Zone, which runs across Southern Haiti and the Dominican Republic. To the west the fault runs through central Jamaica. The Caribbean Plate is rotating clockwise, effectively moving east relative to the Gonâve Microplate.

Plate movements and fault zones around the Gonâve Microplate. Mike Norton/Wikimedia Commons.

See also...

The United States Geological Survey recorded a Magnitude 4.8 Earthquake at a depth of 10 km in San Cristóbal Province in the southwest of the...



The United States Geological Survey recorded a Magnitude 4.5 Earthquake at a depth of 10 km on the north coast of the Dominican Republic, slightly...



The United States Geological Survey recorded a Magnitude 3.4 Earthquake at a depth of 44 km under the southeast of the Dominican Republic, roughly 10 km...



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Hydrated silicate minerals in the Mariner Valley, Mars.


Hydrated minerals (minerals containing water) are considered to be evidence of the former presence of liquid water on Mars. They have been observed at a number of locations on the planet, and seem to have been formed in a number of phases, with the oldest, Noachian, deposits (thought to be approximately 4100 to 3700 million years ago) frequently containing hydrated phyllosilicates, younger, Hesperian deposits (from about 2700 million years ago to between 3200 and 2000 million years ago) containing hydrated sulphates and the youngest, Amazonian, deposits (anything younger than Hesperian) containing hydrated ferric oxides. A variety of hydrated minerals have previously been detected in the Valles Marineris (Mariner Valley), the largest canyon system on Mars, where the central portion contains extensive hydrated sulphate deposits, and hydrated clays, silicates and iron minerals have also been observed.

In a paper published in the journal Geophysical Research Letters on 30 December 2014, Catherine Weitz of the Planetary Science Institute, Janice Bishop of the SETI Institute, Leslie Baker of the Department of Geological Sciences at the University of Idaho and Daniel Berman, also of the Planetary Science Institute describe the discovery of iron rich allophane or opal deposits (hydrated silicates) in the Coprates Chasma region of the central Valles Marineris.

(Top) Mars Orbiter Laser Altimeter topography overlain on Thermal Emission Imaging System (THEMIS) daytime infrared mosaic of central Valles Marineris, including Melas, Coprates, and Eos chasmata. The yellow rectangle indicates the location of the bottom left figure. (Bottom left) Portion of HRSC image H0438_0000_ND4 showing Coprates Chasma. The yellow rectangle identifies the location of study region and bottom right figure. (Bottom Right) Portion of CTX image P18_008141_1647 with CRISM spectral parameters derived from image HRL0000A8F6 overlain in colour (red is olivine index, green is band depth at 1.9 μm, and blue is doublet between 2.2 and 2.3 μm). The Fe-rich allophane/opal deposits are outlined in yellow, whereas blue lines outline smectite exposures. Weitz et al. (2014).

Allophane and opal are semi-amorphous hydrated aluminium silicates, which generally form as weathering products of volcanic rocks on Earth. They are considered to be quite unstable, particularly in their high-iron forms, which tend to break down into iron rich clays. While chemical weathering processes on Mars are thought to be slower than on Earth, it is still unlikely that these minerals could have persisted at the surface for very long periods of time, suggesting that they have either been formed recently (in geological terms) by the action of water, or have been recently exposed by active geological movements, either of which would be a significant discovery.

Expanded views of the areas outlined by black boxes in the bottom right image above. (b and c) Hydrated nanophase Fe-rich allophane/opal corresponds to materials within yellow outlines. Portion of HiRISE images ESP_033010_1645 and PSP_008141_1645. (d) Channel containing Fe-rich allophane/opal (red arrows). Portion of HiRISE image PSP_008141_1645. (e) Example of smectites along the wall rock. Weitz et al. (2014).

The Coprates Chasma region is interpreted as a graben structure, which is to say an area where rock movements have drawn two areas of planetary crust apart, resulting in thinning of the crust in the central area, which in turn tends to lead to subsidence and slumping. The allophane/opal deposits are exposed on an area of slumping (landslips) thought to be in the region of 50-100 million years old. It is unclear if these minerals predated this slumping, and have been exposed by it, thereby potentially representing a greater reserve buried beneath the surface, or whether they are younger material that has formed at the surface as the result of the weathering of other minerals exposed by the slumping.

HiRISE DTMperspective view at 2X vertical exaggeration with CRISM spectral parameters overlain in colour (red is olivine index, green is band depth at 1.9 μm, and blue is doublet between 2.2 and 2.3 μm). The red arrows identify the eastern Fe-rich allophane/opal deposit (whitish blue), which extends across 940m in elevation, whereas the green arrows identify exposures of smectites within the wall rock (yellow-light green). HiRISE stereo pair images PSP_008141_1645 and PSP_007785_1645 were used to make the DTM. Weitz et al. (2014).

See also…

Landslides on Mars typically have much greater runout distances than those on Earth, due to the planets lower gravity and thinner atmosphere. This can lead to areas of layered deposits from different landslides quite distant from the source, particularly within the larger canyons on Mars. Since it is possible to produce approximate ages for such deposits based upon the number of impact...


The surface of Mars has been observed continuously by the Mars Orbiter Camera from 1997 to 2006 and the Mars Reconnaissance Orbiter since 2006. During the time that these observations have been occurring around 200 new impact craters have been observed on the surface of the planet; most of them in dusty areas, where they are easily detected due to the dark blast patterns that surround fresh impacts in these...


The potential of there being life on Mars has been a stalwart of popular fiction for over a century, though to date no signs of actual life have been discovered. Recent discoveries of geological structures on Mars that indicate the presence of large bodies of open water in the early history of the planet. This new understanding of the planet makes the search for evidence of ancient life on Mars a more realistic...


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Asteroid 2015 FC117 passes the Earth.

Asteroid 2015 FC117 passed by the Earth at a distance of 6 542 000 km (17.0 times the average distance between the Earth and the Moon, or 4.37% of the average distance between the Earth and the Sun), slightly 6.45 am GMT on Sunday 22 March 2015. There was no danger of the asteroid hitting us, though had it done so it would have presented only a minor threat. 2015 FC117 has an estimated equivalent diameter of 14-43 m (i.e. it is estimated that a spherical object with the same volume would be 14-43 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) in the atmosphere between 27 and 10 km above the ground, with only fragmentary material reaching the Earth's surface.

The calculated orbit of 2015 FC117. JPL Small Body Database.

2015 FC117 was discovered on 24 March 2015 (two days after its closest approach to the Earth) by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount Lemmon in the Catalina Mountains north of Tucson. The designation 2015 FC117 implies that it was the 2928th asteroid (asteroid C117) discovered in the second half of March 2015 (period 2015 F). 

2015 FC117 has an 679 day orbital period and an eccentric orbit tilted at an angle of 25.3° to the plane of the Solar System, which takes it from 0.95 AU from the Sun (i.e. 95% of the average distance at which the Earth orbits the Sun) to 2.08 AU from the Sun (i.e. 208% of the average distance at which the Earth orbits the Sun, considerably greater than the distance at which the planet Mars orbits the Sun). It is therefore classed as an Apollo Group Asteroid (an asteroid that is on average further from the Sun than the Earth, but which does get closer). This means that close encounters between 2015 FC117 and the Earth are quite common, with the last calculated to have happened in November 2014.

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Asteroid 2015 EG7 passed by the Earth at a distance of 1 044 000 km (2.72 times the average distance between the Earth and the Moon, or 6.98% of the average distance between the Earth and the Sun), slightly before 9.30 pm GMT on Friday 20 March 2015...



Asteroid 2015 FF passed by the Earth at a distance of 1 596 000 km (4.15 times the average distance between the Earth and the Moon, or 10.7% of the average distance between the Earth and the Sun), slightly before 8.30 pm GMT on Friday 20 March 2015...


Asteroid 2015 FE passed by the Earth at a distance of 12 010 000 km (31.3 times the average distance between the Earth and the Moon, or 8.03% of the average distance between the Earth and the Sun), at about 4.45 pm GMT on Thursday 19 March 2015...




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Three homes evacuated after landslide in Des Moines, Washington State.

Three homes have been evacuated following a landslide close to the Salt Water State Park in Des Moines in King County, Washington State, on Friday 27 March 2015. The event started at about 8.30 am and proceeded slowly throughout the day, enabling the residents of the homes to remove valuables and evacuate safely, though at about 3.00 pm the rate of collapse increased sharply, resulting in the loss of most of the gardens of one of the properties, as well as minor damage to the building itself.

Aerial photograph of the 27 March 2015 Des Moines landslide. King5.

Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall. However no exceptional rainfall has been reported in King County, or other areas of (often wet) Washington State in the past few weeks, making it unlikely this was the cause on this occasion. 

Closer shot of the 27 March landslide, showing part of a structure that has collapsed downslope. KomoNews.

The situation is being monitored closely by local authorities, who have not ruled out the possibility of further evacuations if the landslip, currently about 60 m wide, continues to grow. Puget Sound Energy have cut off gas and electricity supplies to the evacuated properties as a precaution. 

The approximate location of the 27 March 2015 Des Moines landslip. Google Maps.

See also...

Six homes have temporarily been evacuated after a landslide partially blocked the Cedar River in Mapple Valley, Kent County, Washington State, at about 10.30 am local time on Saturday 10 May 2013. The...



Three people are known to have died, and several more are in critical conditions, following a landslide near the town of Oso in Snohomish County in Washington State, about 55 km north of Seattle, that occurred...



The United States Geological Survey recorded a Magnitude 3.0 Earthquake at a depth of 27 km, 2 km to the north of Indianola, on Puget Sound opposite...


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Magnitude 1.9 Earthquake in North Yorkshire, England.

The British Geological Survey recorded a Magnitude 1.9 Earthquake at an uncertain depth near the village of Wormersley in North Yorkshire, slightly before midday GMT on Friday 27 March 2015. There is no danger of any damage or casualties from an event of this size, though people have reported feeling it in the village of Hensall, about 10 km to the east of the epicenter, as well as underground at mines in the area.

The approximate location of the 27 March 2015 North Yorkshire Earthquake. Google Maps.

Earthquakes become more common as you travel north and west in Great Britain, with the west coast of Scotland being the most quake-prone part of the island and the northwest of Wales being more prone  to quakes than the rest of Wales or most of England. However, while quakes in southern England are less frequent, they are often larger than events in the north, as tectonic presures tend to build up for longer periods of time between events, so that when they occur more pressure is released.

The precise cause of Earthquakes in the UK can be hard to determine; the country is not close to any obvious single cause of such activity such as a plate margin, but is subject to tectonic pressures from several different sources, with most quakes probably being the result of the interplay between these forces.

Britain is being pushed to the east by the expansion of the Atlantic Ocean and to the north by the impact of Africa into Europe from the south. It is also affected by lesser areas of tectonic spreading beneath the North Sea, Rhine Valley and Bay of Biscay. Finally the country is subject to glacial rebound; until about 10 000 years ago much of the north of the country was covered by a thick layer of glacial ice (this is believed to have been thickest on the west coast of Scotland), pushing the rocks of the British lithosphere down into the underlying mantle. This ice is now gone, and the rocks are springing (slowly) back into their original position, causing the occasional Earthquake in the process.

(Top) Simplified diagram showing principle of glacial rebound. Wikipedia. (Bottom) Map showing the rate of glacial rebound in various parts of the UK. Note that some parts of England and Wales show negative values, these areas are being pushed down slightly by uplift in Scotland, as the entire landmass is quite rigid and acts a bit like a see-saw. Climate North East.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. If you felt this quake, or were in the area but did not (which is also useful information) then you can report it to the British Geological Survey here.

See also...

The British Geological Survey recorded a Magnitude 1.9 Earthquake at a depth of 2 km near the village of Redmire in...


The British Geological Survey recorded a Magnitude 1.9 Earthquake at a depth of 1 km in southern North Yorkshire slightly after 11.30 pm British...


Three homes were evacuated after a 7.5 m wide sinkhole oppened up in Rippon, North Yorkshire, on Monday 16 February 2014. Two...



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Friday, 27 March 2015

Homes evacuated after sinkhole opens up in Swanley, southeast England.

Two homes have been evacuated in the town of Swanley in Kent, southeast England after a sinkhole opened up on Thursday 26 March 2015 swallowing two sheds behind the properties. The hole is described as being roughly two meters by three and several meters deep. There is not thought to be any immediate danger to human life, but Sevenoaks District Council has ordered the evacuation of the houses as a precaution. It is understood that the residents of one of the preperties have accepted alternative accommodation from the council, while the residents of the other have made their own arrangements.

Sinkhole that opened up in Swanley, Kent, on 26 March 2015, swallowing two sheds. BBC.

Sinkholes are generally caused by water eroding soft limestone or unconsolidated deposits from beneath, causing a hole that works its way upwards and eventually opening spectacularly at the surface. Where there are unconsolidated deposits at the surface they can infill from the sides, apparently swallowing objects at the surface, including people, without trace.

The approximate location of the 26 March 2015 Swanley Sinkhole. Google Maps.

On this occasion investigations by Thames Water have revealed a broken sewer beneath the sinkhole, though it is unclear if the sewer breaking was the cause of the event or if it was broken by some earth movement associated with the formation of the hole, as it appears to have been in good order prior to the event (people tend to notice and report broken sewers quickly). Thames Water and Sevenoaks District Council are reportedly working together to find a solution to the problem.

See also...

National geological surveys have traditionally produced two dimensional geological maps showing the outcropping of rock formations, combined with data on the dip of the strata (i.e. the angle at which the beds...

Two teenaged girls were rescues by teams from Kent Fire and Rescue and the Whitstable RNLI after becoming trapped in soft mud at Warden Point on the Isle of Sheppey (off the north coast of Kent in the Thames Estuary) on Saturday 2014. Initial attempts... 


On 8 April 2012, slightly after 2.00 pm GMT (slightly after 3.00 pm British Summertime) the British Geological Survey recorded an Earthquake about 10 km off the coast of Margate, southeast England, at a depth of 5 km. The quake measured 1.9 on the Richter Scale, so it...



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