DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.24#0029
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between quartz grains ; shows perfect cleavage and tends to fray out at the edges ; the mica
also tends to lie along the.bedding planes ; a few grains of zircon showing zoning ; ferruginous
decomposition products between grains.
11. Quartz grains larger than in No. 10 ; altered felspathic material present; slide shows
no muscovite mica, but it is visible in the hand specimen along bedding planes ; ferruginous
material slight.
12. A little muscovite mica ; very irregular quartz grains set in a very little kaolinized
material.
From Hypostyle Hall, Karnak.
13. Very irregular grains with ferruginous cementing material ; slightly decomposed
microline present in small amount; quartz shows corrosion ; whole stone shows tendency to
break up.
14. Similar to No. 13 ; undecomposed felspar ; ferruginous decomposition products
widely distributed ; mica and felspar, probably microline.
15. Quartz grains with ferruginous cementing material and undecomposed felspar grains.
From Girtass Quarries.
16. Very irregularly shaped grains which are not united by any visible cement except
along certain irregular bands where it is of a clayey nature.
17. Grains angular and about half the size of that in No. 16; crystalline aggregate present;
grains in isotropic clayey paste ; quartz has been broken and cemented by paste ; large zircon.
18. Angular grains similar to No. 17 ; absence of marked cement.
19. Grains very angular and elongated ; very little cementing material; the dark scattered
masses in slide more ferruginous than felspathic.
20. Very irregular angular grains, many elongated ; cementing material very little ;
scattered ferruginous enclosures.
21. More finely grained ; a very finely granular paste is present as cement.
22. Differs from preceding ; grains closely set in cement; cement decidedly ferruginous.
Summary.
Nos. 16, 18, 19, and 20 .. .. Angular grains, poor cement, except bands in No. 16„
Nos. 17 and 21 ...... Small angular grains, clayey cement.
No. 22.......... Large angular grains, ferruginous cement.
Though only a small number of specimens have been examined, they indicate that the sand-
stone of Girtass is somewhat inferior in cementing material to that of Silsila, which agrees
with the higher resistance to crushing offered by the latter rock."
In the following table are given a number of analyses of samples of Nubian sandstone
from Karnak Temple, the Silsila quarries, and from Philae.
between quartz grains ; shows perfect cleavage and tends to fray out at the edges ; the mica
also tends to lie along the.bedding planes ; a few grains of zircon showing zoning ; ferruginous
decomposition products between grains.
11. Quartz grains larger than in No. 10 ; altered felspathic material present; slide shows
no muscovite mica, but it is visible in the hand specimen along bedding planes ; ferruginous
material slight.
12. A little muscovite mica ; very irregular quartz grains set in a very little kaolinized
material.
From Hypostyle Hall, Karnak.
13. Very irregular grains with ferruginous cementing material ; slightly decomposed
microline present in small amount; quartz shows corrosion ; whole stone shows tendency to
break up.
14. Similar to No. 13 ; undecomposed felspar ; ferruginous decomposition products
widely distributed ; mica and felspar, probably microline.
15. Quartz grains with ferruginous cementing material and undecomposed felspar grains.
From Girtass Quarries.
16. Very irregularly shaped grains which are not united by any visible cement except
along certain irregular bands where it is of a clayey nature.
17. Grains angular and about half the size of that in No. 16; crystalline aggregate present;
grains in isotropic clayey paste ; quartz has been broken and cemented by paste ; large zircon.
18. Angular grains similar to No. 17 ; absence of marked cement.
19. Grains very angular and elongated ; very little cementing material; the dark scattered
masses in slide more ferruginous than felspathic.
20. Very irregular angular grains, many elongated ; cementing material very little ;
scattered ferruginous enclosures.
21. More finely grained ; a very finely granular paste is present as cement.
22. Differs from preceding ; grains closely set in cement; cement decidedly ferruginous.
Summary.
Nos. 16, 18, 19, and 20 .. .. Angular grains, poor cement, except bands in No. 16„
Nos. 17 and 21 ...... Small angular grains, clayey cement.
No. 22.......... Large angular grains, ferruginous cement.
Though only a small number of specimens have been examined, they indicate that the sand-
stone of Girtass is somewhat inferior in cementing material to that of Silsila, which agrees
with the higher resistance to crushing offered by the latter rock."
In the following table are given a number of analyses of samples of Nubian sandstone
from Karnak Temple, the Silsila quarries, and from Philae.