Videoer fra Hortavær fra 2002 –>

Første mål er å få teksten riktigst mulig oversatt. Da kan jeg sende snuttene til Calvin og få «sluttsjekket» dem. Det er mulig å legge inn en del bilder i stedet for videoen der filmingen er for dårlig.

Det er mulig at jeg kan importere videoen fra Horta i 2002 fra den opprinnelige kameratapen og få bedre oppløsning. Vet ikke om jeg har kamera som kan ta denne type tape lenger.

Det er fem videoer som trenger kontroll av oversettelse:

Horta2002 (dårlig oppløsning, men god beskrivelse).



Host rock

Mafic magma: (Fin video, men dårlig lyd)


Her er teksten jeg har klart å tyde på de enkelte videoene:


Complex igneous intrusion of unknown age, probably Caledonian, probably 460 some million years old. It has its central zone by Burøya and Vågøya.

Mostly dark rocks as diorite that is reacted with marble and other metasediments and has made very strange mineral relations there.

That was originally called “Hortite”. That name is no longer used.

It then has an outer zone. Especially on the western side. Of syenite with very complex magma mingling relationships.

And some metasedimentary rocks, what we are standing in here, that have been completely reacted with syenettic magma.

And then it has a margin to the NW that is the “host rocks” which is various kinds of metamorphic rocks – migmatite, quartzite, maybe some marble-like rocks and so forth.  

And we find that the magma at the “Hortavær” islands were capable of intruding each other in many, many generations.

So, there is a lot of hybridization or magma mixing and magma mingling so you make even a more confused relationship.

All this happened in the middle crust, probably at a depth of 15-20 kilometers.

So it gives us an idea of what modern magma systems are doing at those depths in the crust in places like Italy, Canary islands perhaps, places where syenettic kind of rocks exists.

That`s why we come to study this.

Turns against professor Tore Prestvik and asks: “What more should I say?”.  


There`s a mineral here called vesuvianite. It`s one of the interesting minerals you find in areas where magma has interacted with marble. We would like to recollect the sample so that we have a complete piece a chemical analysis of it because we don`t have that.

Here we have monzonite and syenite. Probably monzodiorite – the rock the vesuvenite is in.

Epidote – to be mentioned?

So, we have intermingled monzonite, syenite and monzodiorite. That`s characteristic of this part of the Horta complex. 

We see a wonderful example right behind Oda. Dark rocks and white rocks intermingling – very photographic.

Vesuvianite – related to garnet. The two minerals are very similar in color and most properties but they are slightly different chemical. Vesuvianite of course is named from Mount Vesuvius.


… and in the ground mass it`s pyroxene. It`s something like this Vogt sampled when he was here (1916) and named the rock. Except he didn`t see garnets or didn`t describe it.

Some of these rocks the pyroxene is several mm long. (Argite?) No, it`s xxx?.

So, this must have been just this boiling massive carbon dioxide and magma and maybe a second melt. And every one is different – every outcrop is different. Iron rich calcium amphibole – ? hasting ?.

The biggest garnets we have seen. So, it`s an unusual rock. (Cut some video and text here).

These rocks represent a mixing of at least one or two kinds of magmas along with marble. And the chemical reaction involved allows the calcium in the marble to be dissolved into the magmas. That has the effect of making very calcium rich minerals crystallizing in? the magmas. Those minerals are pyroxene, garnets, amphibole, vesuvianite, ??sween along with plagioclase feldspar.

So, what we see here are very large crystals of garnets and amphiboles and they are “swimming in” smaller crystals of plagioclase and clinopyroxenes.

And we think that the crystals are so big is that this magma was very rich in water and carbon dioxide and so that allowed chemical elements to move to the crystals and let them grow very large.

The name Hortite was originally named by the Norwegian professor Johannes Vogt in his publication of 1916. It was applied only to these kinds of rocks. And as a result of that it was discredited by the official mineral and rock naming people in the nineteen seventies. And that`s probably a good thing because we don`t need to many rock names. It`s already a torture to the students to memorize that many rock names.

Jostein: Should one rock in the Horta Island be named barnesite?

No!! Rocks are not named for people. Minerals can.

Very few people try to name rocks from places any more. We now have a systematic naming convention.


Host rocks

These rocks are what we call the “host rocks” to the Horta intrusive complex.

And here these rocks consist of migmatites.

Which are rocks that begun to melt as they were heated in the crust.

In this case they melted so much that they began to move because of the pressure they were under.

And as they moved the melt began to segregate into separate zones.

The more resistant parts stayed as relatively solid bits.

These blocks are surrounded by granite which is representative of the melt that formed.

We know from studying the age of these rocks and the age of the “Vega granites” that they have the same age and chemically the same characteristics which makes us think that these rocks represent the source of the “Vega granite”.

If you extend these kinds of rocks beneath Vega that were these rocks that were melted to make the Vega granite 475 Mio years ago.

So, we are here to study the migmatite and in particular to see how the resistant pieces – the blocks – have broken.

Because by studying their size and shape, its sometimes possible to tell the mechanism by which they break.


Mafic magma.

(Nice video, but bad sound because of wind. New soundtrack from Calvin or someone else. )

Here is a place where mafic magma (basaltic magma) grows into the migmatite while the migmatite is partly melted.

The migmatite we have been looking at looks like this rock down here.

When the basaltic magma came into the migmatite it provided a zone for the liquid part ? of the migmatite to collect.

The liquid part compensated to bring back ? the granite and the basalt in the same place together.

And at that point the basalt begun to cool pepply? And it became brittle and it broke into large blocks.

And the granite was still liquid so it could flow around these large blocks and turn? ?? something ?.

We know that this is the case because the migmatite itself is actually a part of the dike and so we can see that this migmatite is getting carried into this granite – just like granite. ? and particular ?? ??. (Changes position).

So, the migmatite is actually being stretched into the granite so we know the migmatite was capable of flowing. The granite was capable of flowing – as they were both breaking up the diorite.  As pieces of brittle ? rock.

Even though the diorite provided the heat ??to work. That`s because the diorite becomes solid at a much higher temperature than the granite.

So, we can call this a hidden big ? ? ? ? ? dike.


Kvartsitt – kort snutt som det ikke trengs oversettelse av.


Link til videoene: