Meltwater canyons in Nathorsts Land, East Greenland

 

I'm intrigued by some rather strange valleys on the northern flank of Nordvestfjord in East Greenland, in Nathorsts Land.  Two of then runn approx NE - SW, and the largest channel (the southernmost one) runs approx E -W.  The northern channel, just to the south of the puramidal peak called Trianglen,  has a prominent north-facing wall and is not very deep -- maybe 200m - 300m.  It is may be 2 km long.  The widdle channel is about 5 km long, and has a depth of c 700m.  And the southern channel, which has an elongated lake on its floor, is about 8 km long.

These channels all carry signs of intensive glacial erosion and aerial scouring -- and glacial diffluence has clearly operated at some time -- but the channels do not obviously connect a glacier catchment with a discharge route, and I therefore speculate that at certain times during the Quaternary, during phases of catastrophic glacier melting, they may have been cut and used by huge volumes of meltwater.

I haven't found any references to these channels in the literature, and I will need to do some more research............

Probable bias in the zircon-apatite fingerprinting paper

Typical zircon grains from another deposit

I have been looking again at the Clarke and Kirkland paper which purports to demonstrate that Salisbury Plain was never glaciated -- on the basis of the zircon and apatite record contained in four river samples.

Detrital zircon–apatite fingerprinting challenges glacial transport of Stonehenge’s megaliths. 
Anthony J. I. Clarke & Christopher L. Kirkland
Nature Communications Earth & Environment | ( 2026) 7:54
https://doi.org/10.1038/s43247-025-03105-3

https://brian-mountainman.blogspot.com/2026/01/new-study-on-salisbury-plain-zircon.html

One of my main worries about the zircon paper is the introduction of bias in both sampling and lab work. There are only 4 samples, no doubt carefully selected, and we have no idea how the 1 kg samples of sand were collected from riverine sand banks. Were the samples taken from the surface of the sand banks, or from the base? Or all mixed up?  From what we can see, they were "bulk samples"........

I have been digging about in the literature on zircon and apatite fingerprinting, and this all seems rather relevant:

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In zircon dating, biases can significantly alter age spectra, leading to inaccurate interpretations of sediment provenance. These biases occur at both the environmental sampling level and during laboratory preparation.

(a) Sampling of Sandy Beds in Rivers

Sampling river sands introduces "natural" or "environmental" biases that can cause certain age populations to be over- or under-represented:

 
• Hydraulic Sorting: Rivers spatially fractionate minerals by density, grain size, and morphology. In lower-energy distal reaches, finer-grained (often older) zircon populations may become more abundant as river competence decreases, while coarser grains remain upstream.
• Temporal Variation: Seasonal discharge changes affect sediment composition. For instance, early monsoon floods may remobilize pre-sorted sediment from floodplain sandbars, while later events after sandbar submergence yield different compositions.
• Zircon Fertility: Not all source rocks produce zircons at the same rate. Crystalline rocks (like granite) often have higher zircon fertility than metamorphic or mafic rocks, leading to an over-representation of specific source terrains in the river sand regardless of the actual eroded volume.
• Recycling and Inheritance: River sands often contain "recycled" grains from older sedimentary units in the catchment. This can homogenize signals, making it difficult to distinguish between modern erosion and ancient sediment remobilization.

(b) Lab Processing Biases

Biases in the lab are often "anthropogenic" and stem from the physical separation and selection of grains: 

• Grain Size Fractionation: Standard heavy mineral separation (e.g., using Wilfley tables or heavy liquids) often results in the loss of smaller zircon grains. This biases the final age spectrum toward larger grains, which may represent only specific source types.
• Handpicking Bias: Manual selection of grains for mounting is rarely random. Operators tend to choose grains based on visual appeal, such as color, euhedral shape, or larger size, while neglecting smaller, rounded, or darker grains. Bulk-mounting is often recommended to mitigate this.
• Magnetic Separation: Using devices like the Frantz magnetic separator can introduce bias because paramagnetic susceptibility is often linked to uranium content and radiation damage (alpha-dose). Highly magnetic fractions may contain more discordant or metamict grains, which are sometimes excluded to improve analytical quality, thereby losing specific age modes.

==========================

Another major issue is that in the study there were no control sites.   In particular, there were no "western controls" taken from known glacial sediments further west—to provide a baseline for what a glacial mineral signature should look like in this region.

Needless to say, this debate is not over........ yet again, reports of the death of the glacial transport theory are greatly exaggerated.

https://doi.org/10.1016/j.earscirev.2020.103093

Google Earth 3D landscape representations

Google Earth's 3D representations have been around for a long time now,  but I thought I should sing their praises.  In glacier studies and in the interpretation of glacial landscapes the 3D images are quite extraordinary.  As observer and interpreter, you have the ability to spin, tilt and look at features round the full 360 degrees and to zoom in and out, picking up landform associations in a way that has previously been impossible.  Here are just a few recent images I have collected through screenshots.

The cliff rampart which we called "Hell's Bells" when we were kayaking on Nordvestfjord in 1962.  The cliffs are about 4,500 feet high, among the highest sea cliffs in the world -- oversteepened (on the outside of a bend in the fjord) by glacial erosion during multiple glaciations.  Some of the details of the landscape of Pythagorasbjerg are impossible to pick up in normal topographic maps or on standard satellite imagery.

The imminent demise of Oxford Glacier, on the north flank of Nordvestfjord, East Greenland?  The glacier is in dire straits.  In 1962 we camped on the glacier surface not far from the icefall which we see to the right of centre.  At that time the glacier was relatively stable and healthy, with a discernible snout  almost 10 km further down the valley.  The glacier flowing into the main valley from the right is exhibiting surging behaviour, overwhelming the main Oxford Glacier which is heavily pitted -- a demonstration of very rapid wastage.

Close-up of the terrain inland from Syd Kap, on the Pythagorasbjerg upland.  Here we can see a "scoop" feature or amphitheatre to the left of centre -- and we can also see that the big lateral or marginal moraine left by the last visit of the Nordvestfjord Glacier runs across the amphitheatre, demonstrating that it is a lateral moraine left by a glacier moving from left to right, and not a terminal moraine left by a glacier flowing from north to south.

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Active landform creation: Daugaard-Jensen Glacier

 

Thanks to the wonders of Google Earth's 3D representations, it's now possible to examine modern landform creation in much greater detail than ever before.

I was particularly struck by this image which I copied when I was trawling about the other day, showing the northern flank of the Daugaard-Jensen Glacier -- a huge outlet glacier draining the Greenland Ice Sheet into Nordvestfjord.  This is a relatively stable glacier which has a very rapid discharge rate -- it moves at almost 3 km per per year, which is comparable to the velocity intermittently affecting smaller surging glaciers.  About 10 cubic kilometres of ice are discharged into the fjord every year.

The 5 km wide snout has maintained a relatively stable position over recent decades, and this means that the ice edge positionh in the glacier torough is also relatively stable.  This of course favours the creation of  lateral morainic ridges, and on the image above we can see a fine continuous marginal moraine extending all the way to the snout.

What intrigues me particularly is the creation of kame terraces in the elongated ice marginal lake on the glacier side of the moraine.  This goes some way to explaining the pecular features observed on the valley sides of Kaldalon, in NW Iceland.  See my post:

https://brian-mountainman.blogspot.com/2025/12/how-kaldalon-kames-are-formed.html

Maybe they are not so peculiar after all!

I am not sure what englacial and subglacial meltwater conduits there may be on this lower part of the DJ Glacier.  But it's clear that the composition and bedding of the morainic ridge and the terraces must be highly variable, with the additional incorporation of rockfall debris from the valley sides and also debris from the alluvial fans linked to steep gullies high up on the mountainside.

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Note:  the ice velocity in the Daugaard-Jensen Glacier may seem spectacular, but it pales into insignificance when copmpared with the Jacobshavn Isbrae in West Greenland, where velocities of up to 18 km per year have been measured.

The calving front of the Daugaard-Jensen Glacier.  The recently calved big tabular bergs have dimensions of c 1 km x 400m.  The sea is covered by frozen slabs of pack ice and incorporated brash ice / icefront debris.

Flyver Fjord (photo by Ernst Hofer).  This is a long tributary fjord on the south flank of Nordvestfjord, which is not itself the scene of a calving icefront.  Almost all of the icebergs here have come from the calving icefront of the DJ Glacier, carried in by winds and currents.  The fjord is famous as an "iceberg graveyard"..........

Portishead gneissic erratics?

Thanks to Tony for drawing this to my attention.   I have seen references to the glacial deposits of the Nightingale Valley on Portishead Down (Chris Hunt, p 144 of the QRA field guide to the Quaternary of Somerset) but not to any glacial deposits on or close to the beach.  I am intrugued by the suggestion that the blocks of gneiss are of "identical mineralogical composition" to the famous Porthleven Erratic.

It is possible that these erratics have come from the nearby Woodhill Bay Conglomerate, which contains far-travelled igneous and metamorphic pebbles and cobbles -- but these tend to be very small, and rather rounded.  The reference to "angular blocks" on the beach suggests a quite different origin.

I will check this out directly with Prof Brian Williams.  Watch this space........

Portishead Beach -- Royal Hotel section A, near the steps

A further point of interest at this particular stop is the presence, in fair abundance, on the gravel beach of angular blocks of biotite-garnet gneiss. Obviously exotic to this area two suggestions as to their occurrence have been put forward: the boulders may be of glacial origin, erratics produced by southerly moving ice during the Quaternary; the material may simply represent discarded ship’s ballast. A point in favour of the first theory is the presence of a 50 ton glacial erratic of identical mineralogical composition at Porthleven in Cornwall. Against this idea is the fact that the gneiss is totally restricted to this one locality along the Portishead coast and that this locality is in juxtaposition to Portishead Docks. Their occurrence, therefore, is a matter for further debate.

The sedimentology and structure of the Upper Palaeo-

zoic rocks at Portishead

Geological Excursions in the Bristol District

Chapter 3

The sedimentology and structure of the Upper Palaeozoic rocks at Portishead

B. P. J. Williams and P. L. Hancock

https://bristolgeology.com/chapter-3-portishead/

The Giant's Quoit at Porthleven

https://brian-mountainman.blogspot.com/2010/06/sea-ice-and-giant-erratics.html

Avon Gorge -- another possible source for the Meaden Cobble

Further to my post about possible sources for the Meaden Cobble, thanks to Tony for drawing my attention to the following publication:

https://bristolgeology.com/avon-gorge/ 

The Black Rock Limestone is very widespread, and at the moment we do not have sufficient evidence to suggest which of the many possible outcrops it might have come from.......

https://brian-mountainman.blogspot.com/2026/02/the-meaden-cobble-probably-from-somerset.html

The Arcturus Glacier surge

 

Above we see two photos of Malmbjerget in East Greenland.  The "red mountain" contains the biggest molybdenum resource in Europe, and is currently the scene of a massive open pit mining proposal with a capital investment budget of over a billion US dollars.  The proposers, Greenland Resources Inc, are currently trying to raise an initial USD 820 million, but full consents are in place, and there is a big documentation available re project proposals, environmental assessments etc.  The project is so vast that we are talking in effect of the industrialisation of the Werner Mountains and the Mestersvig area to the north, on the shore of Kong Oskars Fjord.

The reddish coloured outer tip of the mountain, between the two glaciers, will be completely removed by the working of the open pit, and there will be vast infrastructure developments as shown on the map below.

The figures are mind-boggling.  203 million tonnes of waste will be stripped during the working of the open pit, and 115 million tonnes of ore will be taken out, initially stored and then taken out to be milled. Of this, 75 million tonnes of waste and low grade ore will be stored in huge stockpiles on the surfaces of the Schuchert and Arcturius Glaciers.  Surface roadways for heavy plant traffic will be partly on the glaciers themselves and partly on adjacent valley sides.  A 10 km tunnel may or may not be built under the Mellem Pass, to connect the open pit to the valley to the north -- it is planned to have an entrance somewhere near Kolossen.  Also running across the mountain range will be an aerial transporter system about 26 km long, designed to export 35,000 tonnes of ore per day.  No supporting towers can be built on the glaciers, so there will have to be at least two very long spans, one across the Arcturus Glacier and the other across the Mellem Glacier -- and that means at least four massive towers.

A glaciological study of the Arcturus Glacier, designed to understand the likely impacts of this mining / quarrying proposal, wasa published in 2009:

 Glaciological investigations at the Malmbjerg mining prospect, central East Greenland. 

https://www.researchgate.net/publication/242584915_Glaciological_investigations_at_the_Malmbjerg_mining_prospect_central_East_Greenland 

The 2008 measured velocity is 18 m per year. Quote: This can be compared with the present-day average velocity of 22 m per year obtained from feature tracking on two orthophotographs from 2005
and 2007, and using theoretical results relating surface velocity with mean velocity over a cross-section of parabolic shape (Paterson 1994). Considering the uncertainties involved, we conclude that no imbalance has been detected to suggest that a surge of Arcturus Gletscher will occur in the near future.

Clearly that assumption was unwise, because the two photos at the head of this post show that the Arcturus Glacier has recently surged.  I have no dates for the photos,  but the lower one was clearly taken more recently than the upper one.  The surge has carried the snout of the Arcturus Glacier into and onto the surface of the Schuchert Glacier.

Here is a Google Earth 3D representation, dated 17 July 2025:

There are actually two Arcturus Glacier surge loops -- the outer one is not far from the present snout position of the Schuchert Glacier.  This suggests to me that Arcturus Glacier is more active than the Schuchert Glacier, and that it has quite a high surge frequency.

I'm contacting the glaciologists who undertook the Arcturus Glacier study -- but it seems to me that the complexities of the local glaciology have not been adequately taken into account by the proposers of the  open pit project.  The knock-on effects of the major environmental disruptions involved in storing 75 million tonnes of waste and low-grade ore on the surfaces of two glaciers with known surging behaviour are therefore underestimated.

This behaviour will also affect the stability (and hence the cost) of thr transport roadways built on the surfaces of the two glaciers.

I have further concerns about the proposals to build a 1 km airstrip capable of dealing with Hercules transport aircraft on the expansive area of ice-cored moraines beyond and to the west of the Schuchert Glacier snout.  In the published reports there is NOT an adequate assessment of the civil engineering challenges presented.

Watch this space.........