Geo-Environmental investigation of Sahure pyramid complex, Abusir Archeological site, Giza, Egypt

: Abusir is the name of an elaborate burial area, dotted with 19 pyramids other temples, stretching on the western side of the Nile from the south of the Giza Plateau to the northern rim of Saqqara. It seems to have been created as the resting site for the Pharaos dated from 2494 to 2345 10 BC. The name Abusir, originally spoken as Busiri, means” temple of Osiris”. Over time, the name has become so popular, that more than 60 villages now carry this name. But only one is the archaeological site. This paper does not refer to all of the Abusir archaeological area, but focuses one of its most important sites: Sahure pyramid, one of Egypt’s little known, but heavily damaged treasure. One of the highlights of the relevant research is the discovery of a piece of cement (Basaltic mortar/concrete), which consists of several materials and which is harder than any cement produced today and detection of a clear and significant Anorthite mineral (Plagioclase) in the mortar sample which had been proven by XRD, XRF (analysis) and Polarized light microscope (investigation). The main objectives of this paper are 1) to reveal and identify the construction materials of the pyramid and the construction of the pyramid,2) to evaluate the durability and vulnerability of the Ancient construction materials of Sahure pyramid,3) to compare the decayed patterns of the different construction materials, 4) to study the pyramid building materials from geological, meteorological, geochemical , petrological and petrophysical point of view, and 5) to present a proposal for scientific conservation and protection of the pyramid. Laboratories and field studies have been carried out by researchers from various countries to investigate and understand the problems of the pyramid leading to the final results which confirmed the impact of the geo environment conditions on the structural and engineering stability of the pyramid.

.The burial pyramid of Sahure is 84 relatively small, only having a base of around seventy-eight meters and rising to a height of forty-85 seven meters. However, it was built using better quality stone of more diverse types than the 86 pyramids of the fourth dynasty (verner,M.20001) [10]. It is thought that the pyramid was built on a 87 base of at least two layers of limestone, but the base has not been excavated so this is simply an

98
Sahure's pyramid was constructed in enriched and various kinds of stones for construction.

99
The casing stone of the pyramid is massive like the casing stones at Neferefre's (unfinished 100 pyramid) or great pyramid and the measurements of blocks in comparison with Neferefre's 101 unfinished pyramid measured as 5m × 5.5m × 1m (verner,M.2001) [10]. The inner chambers were 102 similarly cased, but using significantly smaller blocks (Verner,M.1994) [11].The core of the pyramid  [10,11,12].This technique of construction is less 105 cost and less efforts and less time but the casing stone constructed by utilizing high quality 106 limestone from Tura and Massara quarries (Verner,M.1994) [11].

107
Because of the poor circumstances of the pyramid, the layout of the pyramid is slightly not 108 measured excellently (verner,M. 2001) [10]. The pyramid had a base length of 78.5m and 48m high 109 figure 5(verner,M. 2001) [10].The architects made a notable error in demarcating the base, causing 110 the southeast corner of the pyramid to extend 1.58m too far east (verner,M. 2001) [10]. The pyramid 111 is surrounded by a limestone which used for paving, except for where the mortuary temple stood 112 and paved by using basalt, and is accessed from the temple's north and south sides, enclosing the 113 courtyard is a tall, rounded enclosure wall 3.15m thick (Borchardt, L. 1910) [13].

114
The pyramid substructure access is found slightly above ground on the pyramid's north face

123
The reconstruction of substructure accurately was so hard word as the corridors so damaged 124 from the thieves and the loads(verner,M. 2001) [10]. for the construction materials for the pyramid of Sahure, the shapes of decayed stones as following:     3 )

230
Some fragments from the quarries which are represented for the construction materials and

488
Free quartz grains occur as very fine to fine-grained with rounded to subangular outlines.

504
In conclusion, the sample is affected by mild alteration over essential mineral constituents.    532 Table.11. The natural weight, dried weight and saturated weight and some petro-physical 533 properties for the core stone (sandy limestone) of the pyramid.

555
Sahure pyramid has been affected by many factors of deterioration and damages for its

624
Finally, the research contributes in presenting an important study for identification of the 625 ancient materials and their localities which used in the pyramid construction, also this study is 626 considered as technical study for urgent needed restoration for the pyramid.

632
The whole database construction, investigation and analysis are presented in the manuscript 633 had been carried out by the first author. Second author reviewed and supervised the paper. All 634 authors read and approved the final manuscript.