Abstract
The present article deals with the heavy mineral and placer formations taking in consideration, what is a heavy mineral, types of placers, principles of placer formation, and general survying of some placers in egyptian deserts. The field and laboratory works are also discussed in articles. The mesh sizes of stream samples which are more suitable as well as the procedure of making a concentrate are conscidred. also the economic value of heavy mineral and its relation to other geology branches. Among the examples of egyptian placers are cassiterite, zircon, rutile, tourmaline, beryle, ilmenite, garnet, chromite, magnetite gold and sheelite. also the most famous localities are : W. ALLaqi, Qattara-Siwa , G. Mueilha, Aba Dabbab, Igla, Nuweini, G.Atawi, G.Mashbih, Qena, Eastren Coast of Gulf of Suez, At uwaynat.
Introduction
Heavy mineral means a resistate mineral with specific gravity greater than that of quartz and feldspar (i.e. greater than . 2.7). They are commonly accessory minerals in rocks, and relatively unaffected by weathering and mechanical disintegration and they tend to accumulate with weathering products of the parent rocks and may be found in thoroughly weathered rock as saprolite or laterite or in residual and colluvial soils, and in stream sediments. The study of heavy mineral indicates gross regional lithology, m.etamorphic grade, contact~, and metasomatic or hydrothermal activity. The heavy minerals . are about 1 to 2% of weight of sediments and may form ollly n l~ few parts per millions of the sedhnents and usually art' tIll W.rl' ',. than its percent in weathered rocks. . 0,
The study of heaVy mineral consists of: -
I-Measuring the variety of minerals.2-Measuring their abundance.3-Measuring their areal distribution in streams & tracts of ten of thousands of square kilometers. It is used in successful exploration for gold, platinum, diamond, sillimanite, kyanite, zircon, monazite, rutile, the ores of tin (cassiterite,) titanium, aluminum, chromium, tungsten (\vollframite), sheelite, tantaIum, and rare earth. It is of little use in areas covered by out .., wash of glacial depris or covered by vegetation. Relief and pattern of streams affect the heavy mineral reconnaissance as n' these factors affect the scale of the covered areas.(e.g. the satisfactory map scales are 1 : 100,000 to 1 : 250,000 where~ the area covered is between 10,000 to 20,000 km2 ).
• ... :- .~ .
. ning method. fig.(l). Separation of heavy min~ralS by pan
Sample intervals: -
1-Sample intervals are varied and depend upon the purpose, the .)1 type ,of material sampled, geographic factors and map scales. Intervals are great =50 to 100 km2 for regions of thousands \{ m1. l :, for plotting on maps with scale 1:2,500,000. Intervals of f)'~h) :- . , km2 for areas of 300 to 700 km2 for gold and sheelite researche8 \ ., on maps 1 :24,000 to 1 :62,000. Sample intervals of 2,5 to 5 km2 for detailed distribution of all resistate heavy minerals in areas =11,000 km2 and 8,000 km2 for industrial minerals as ilmenite, rutile, sillimanite, kyanite, garnet, monazite, xenotime, and zircon on maps of 1 :250,000 scale. 2-Intervals is widened in high rugged area with relief 2.5 km. 3-Heavy mineral reconnaissance cannot be used in great tracts of swamp, huge alluvial plains, or regions covered by wind-blown sand and area covered by drift from continental glaciation.
Number of concentratl\';.ti
The number of concentr:ate That can be prepared by a panner in
a day depends on : _ 1\;\;>
I-S~ze of the s~ples 2-Densetr popu~ated regions are id, HI HII'I1,ri rapId progress In the field of reconnaIssance because the roads _.
and trails evolved for the communication of large population ('. give ready access to sample localities.3-Easy of dug.4-Sample intervals.5-Availability of water.6-Accessibility of successive ('.'
sample localities as the travel by jeep is more excellent and one man can make 10 concentrate in one day if water and jeep are available and sample size is gravel and easHy dug or one. concentrate in 30 minutes. . l
B-Laboratory study
Laboratory study includes: -
1- Identification of the mineral varieties.2- Their abundance in is'' the concentrate. 3- Makes permanent records and results. 4¬Stores the concentrate for further study.
The mineralogical analysis is asfollow: - .
1- Weight of the concentrate.2- Separates the magnetite. 3- @ Weight the magnetite-free fraction.4- Evaluate the magnetite-I free fraction of the concentrate for radioactivity with Laboratory counter.5-Examine this fraction using ultra violet light for i fluorescent ore minerals such as scheelite.6-Sieve the magnetite
- free fraction of the concentrate into 3 to 5 appropriate sizes of grains for counting. 7-Weight sieve fractions. 8-Split each sieve fraction into the requisite 150 to 300 individual grains needed
for optical identification and counting.9-Identify, count and record the mineral in each split. 10-Calculate the numerical frequency of the grains to determine the weight percentage in the concentrate.ll- These result then stored for further study -by filling these data through Standard punch cards of the manually stored type, with a code adapted to the language of the area, . which is easy retrieval for pertinent data. . (
~
~ ~
~
C-Presentation of data
fj
~
t~r"
t I-This method merely shows the presence or absence of ~ ~ particular minerals, like gold, scheelite, and monazite in
,
~ particular areas.
2-Another method shows, the abundance of a particular mineral, such as monazite in crystalline rocks by contours drawn at ~ logarithmic intervals from 0.00001 percent to 0.01 percent.
3-A third method shows the weight percentages, using iso grams I:Q-i ~ of 15 minerals in concentrates from stream gravel, in this ~ method, which is atypical example. of a heavy-mineral
~ reconnaissance, individual maps were made for the common (\j.~ minerals ilmenite, magnetite, garnet and zircon. Maps
~ combining one common mineral with one less common mineral ~y were made for monazite plus xenotime, rutile plus tourmaline, , ~ sillimanite plus kyanite and epidote plus staurolite.In some types ~q)'
.. R> of heavy mineral reconnaissance, the weighs of the heavy fct;, mineral (absolute abundance) may be more useful than the ~ percentage (relative abundance). .
~
D-Relation to other geological methods
~
Heavy mineral reconnaissance is complementary to
~ conventional methods of geological, photogeological, ~ ~ geochemical, and geophysical surveying. Ideally the heavy- ~ mineral reconnaissance should precede a guide geological
~ mapping and can be accompanied by airborne geophysical Mi
survey. Geochemical methods and heavy-mineral
~ reconnaissance can be used effectively together. One of the ~ simplest ways of using the two in union is to collect a s~mple of
~ clay or silt at each locality where a concentrate is taken and to ~ use rapid methods of mineral analysis to determine the ~';l abundance of copper, lead, zinc and other elem{mt. Also, the
~ determination of the abundance of minor elements in detrital ~ magnetite which removed from the heavy-mineral concentrate is
~ analyzed spectrographically for manganese, titanium, chromium, @
~
~
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:, 1- Wadi Allaqi ; Abu Dabbab. S .E • D.
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Part IV
Some Egyptian placer deposits
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Hussein Abd El aziz (1998), The alluvial sediments in
~ wadis draining the basement outcrops contain at the favorable ~ depositional sites, some placer deposits of gold (Wadi Allaqi),
~ cassiterite (Wadi Mueilha) or columbite - tantalite - cassiterite ~ (Abu Dabbab). Pre-Cambrian rocks are the source of Minerals in ~ these deposits
~ 2-Qattara, Siwa Aeolian sand. . ~
Hdmtltffl tlfttllfw/i.t (' ••.• ) ~""" ,*" ••.• t dU, ticttvy mineralS
~ assemblage of the Aeolian sand qeposits in Qattara - Siwa area ~
is rich in opaque and metamorphic minerals (staurolite and
~ garnet) in addition to the ultrastable minerals (rutile, zircon and ftI?;, ~ tourmaline) and metastable minerals such as amphibole ~ (hornblende).
:, 3-North Igla area (C.E.D). @
El Miligy and El Said (1988), reported that, the economic
~ heavy minerals north of Igla area (C.E.D) are zircon, Nb - Ta ~ ~ min~rals, ~onazite, rutile and cassite~ite in variable am?unts in ~) wadI allUVium and vver~ concentrated In the area of WadI Heyay, . wadi Dobr and wadi Et Nabi (z:r is 0.031 kg 1m3, of W, l)obr Im and WHeyay) and is 0.14 kg/m2 at w: Dober and 0.16 kg/U13 in
~ w.• El Nabi .In general the percentage of cassiterite in Igla area Mt ranges from 1.86 to 2.78 kg/m3,Abu Dabbab is 1.58 to 2.8
~ kg/m2 where in Nuweibi is 0.429 kg/m2. Zircon (ZrSi04) has fJrn its main location near to granophyre granite and biotite granite intrusion and represent the most wide - spread heavy mineral in f:i:f;
b> the area as yellow to brownish yellow fractured bipyramidal ~ crystals. Nb -Ta minerals, as fine pale to dark brown and
~ greenish fractured bipyramidal crystals it is mainly in w: Heyay ~ Monazite (Ce Ba Di) P04 is yellow elongated and subrounded
~ . ~
~ ~ ~
:R
~ grains fractured .. Commonly. Xenotime (YP04) as yellow bipyramidal prismatic crystals. It is rare in the area. Sheelite (Ca
5> W04), as fine white grains showing bluish white fluorcsc'cnce
~ by exposure to ultra violet radiation. In W Heyay. "Rutile (1',02) \ as deep red fine elongated grains. Cassiterite (Sn02) as nlediunl ' ~ grained angular to sub angular honey to dark brown crystals in "Ri: Heyay. In general, the heavy economic minerals are ~ concentrated mainly in the fractions less than 8mm diameter in alluvium nearer to the bed rocks, and the disintegration products
j ofmetasomatic Gattarian granites (apogranites).
rr 4-Black Sand of Rossetta •
Ibrahim (1995), studies the heavy "minerals concentrate
~ from black sand deposits of Rossetta and concluded that two are , the more important c.f. zircon and rutile. He found that raw sand
~ sample weighing 421.3 kg was prepared which consists oft-<' 55.63% ilmenite, 18.670/0 magnetite, 10.23% zircon~ 1.86% ~ mtile, 0.7% monazite~ 11% garnets and other gangue minc~rals ~ including green silicate, quartz, feldspars &about 1.85% slilTIes. The majority of both zircon & rutile are behaved a'i diamagnetic ~ (non-magnetic). Zircon is prismatic to elongated while rutile grains show different degree of roundness from sub rounded to .f'y highly rounded with little euhedral crystals and ranges in color from black, brown, red, orange to yellow. They are of two ~ varieties one is primary and secondary rutile (leucoxene) formed -=" ~ due to hydrothermal alterat of ilmenite result in transformation I into one or more of titanium bearing minerals as rutile, anatase, b brookite, sphene and or pseudobrookite .. with or without magnetite and some ilmenite. Through time, the host titanium¬f» bearing mineral will be the only remained. Gold, cassiterite, ~ chromite, xenatime and monazite are also found through black sand of Rosseta. Secondary rutile show wide range of specific ~ gravity due to presence of composite grains and exsolved inter ~ growth of iron in such composite grains also the degree of iron ~ removal by weathering. ~ 5- Wadi F eiran Pleistocene sediments( S. ~ Sinai). ~ Niazy (1997), reported that the heavy minerals of the Wadi ~ & F eiran Pleistocene sediments (W est- Southern Sinai, Egypt) 'are M ~ ~ ~ ---- --- --- --- --- •:- -.:- -:- .:. .:. . :. .: . .:. .:. .:. -:. -:- represented by sub angular to sub rounded oxidized to martite, ilmenite, geothite, with opaque grains of magnetite rare of ~ cassiterite , molybdenite and chalcopyrite rare of zircon, apatite, & fluorite and topaz epidote', chlorite, biotite, hornblende and pyroxene. Table (1 ) show the distribution of heavy minerals in ~ ~ sand fraction of W. Feiran Sediments and granite pegmatite, ~ west southern Sinai. The Pleistocene sediments of Wadi F eiran 00 are considered as lacustrine sediments and show the characters ft of fluvial and river deposits. The gravel conglomerates show '~local glacial depositional environment. While the fine and ~ medium sands show fluvioglacial environment transported by :'~ rivers and tractive current. . ~ ~ 6-Al Uwaynat gold deposits (S.E.D. ).- @ Nairn. (1996), make regional geological and geochemical .:~ exploration at Al Uwaynat area and resulted in, there is N:• anomalous values of gold in quartz veins, alteration zones, ~ banded iron-formation, iron-bearing quartzite and some dykes. &l .. On the other hand, minerals with rare earth elements (REE) ~ accumulate in the placer deposits and show anomalous values .= for Y, Yb, Ce, La. The friable and panning samples (76 and 82 samples) were collected from major. wadis cutting through ring .~ complexes and granitic rocks. 7 - Western Sinai (eastern coast Gulf of Suez) ~ ~ Mousa (1995), study the heavy minerals_Of the western .::~ Sinai coast of some soils along the eastern coast of Gulf Suez. @ Soil materials are formed of fluviatile deposits that are :~ transported by currents of high velocity. The soils of the 00 southern and central localities are characterized by abundance of ,:~ biotite, brown garnet and bipytamidal zircon as well as pytoxene ~ and amphibole minerals while the northern locality is dominated ~ . by sub rounded and rounded zircon; colorless and pInk garnet. 00 The soils of the northern localities are derived from the'R cretaceous-tertiary sedimentary sequence; these of the southern locality are derived from the basement rocks, while central soill'lC' is from the basement and sedimentary rocks. Rutile is yellowish ~ brown and reddish brown, red-shaped having sub rounded edges. t{¬. Cassiterite as pale brown, reddish brown and golden yellow with .. ~ '-:. . :. .:- . : . . :. -.: . .. : . . : . :::::E:"-NX . ~ .;::, .~ :~ sub rounded edges and some prismatic. Garnets as brown, ~ colorless, pink, yellow and green with sub rounded edges and ~ pitted surface fig. Show the 'frequency percentage of heavy r-r;:,' ! minerals in the studied localities along the eastern coast of Gulf , of Suez. Staurolite as golden yellow, brownish yellow straw!h .~ yellows, prismatic with sub rounded edges. Zircon as colorless, ~ prismatic with rounded to sub rounded edges without inclusions :~ and very low amounts of pyramidal terminate. Andalusite as ~ colorless, straw yellow with sub rounded edge, tourmaline, ~ green, pale brown, greenish brown, yellowish green, prismatic &: with sub rounded edge. The faint pleochovic variety is predominate at the central and northern locali~ies while the dark ~ pleochovic variety is present in the southern locality. The average percentages are as follow: - Rutile 0.5%, brookite 1.20/0, cassiterite 1.80/0, staurolite 00 5.60/0, zircon 3.80/0, andalusite 3.90/0, tourmaline 1.10/0. The ~ highest value of cassiterite is present in the central locality at ~ .: wardan downstream attaining 15-250/0 due to its ~ .~ derivation from veins and pegmatites (granite pegmatite . . ~ boundering the central locality. While tourmaline may be ~ derived from granite pegmatite at the southern locality about ':~ 4.40/0. The highest value of garnet 8% may be derived from soda ~ rich igneous rocks as nepheline syenite, phonolites at southern ca'y locality or due to metamorphosed limestone. Staurolite (13.3)~• rnay from igneous and metamorphic rocks of Feiran belt. Zircon ~ 10.7% highest value may be from acidic and intermediate ~ .~ igneous rock at sudr upstream of southern lo~ality. 8-Shalatein, Abu Ramad, Halaib area (S.E.D.) Egypt)). 00 Oweissand said (1998), make gold exploration at shalatein ~ Abu Ramad Halaib area, south E.D. Egypt and found that, ~ gold occurs in quartz veins (0.3 40)g/t, alteration zones (0/3 tm 12)g/t and the results of mineralogical studies of heavy fractions ~ of panning samples show the presence of gold, rutile, zircon, mo\lazite and )te,notime in the heavy fraetions of alluvial .... :• 00 sediments. They rrttd~that the mineraliz of gold is hosted by N:. volcanosedimenty rocks, ultramafic rocks and their associated :~ intrusives and recommended for further exploration. The rocks :: ,':' -.:- .:. ::- .:. .:. '.:. .:. .:. .:. .:. .:. .:. 19 -:.' ~ are highly folded. Most of the ancient mines (rnadari, komit, EL ~ tuir and Elfawi) are restricted to these folded areas. m ~ .~ 9-Qena district (Nile valley ,Egypt) early Pleistocene sequence ~ Hassaan.(1996), studied the heavy Ininerals of early .;fy Pleistocene sequences in Qena district, Nile Valley, Egypt, the A:" main heavy minerals are zircon, tourmaline, rulite, epidote, staurolite, kyanite and garnet are mainly detected in the sands of ~,. 00 Idfu and Armant formation with varying degrees of abundance. ~ The gravels of Idfu are the main facies and are mainly rounded ;:~ to well rounded reflecting long away de~ivation frOln different ~ ~ basement rocks types of the Eastern Deserts. While the gravels ~ of Armant and Issawia formation are angular to sub angular ;:N indicating short way derivation from the surrounding Eocene ~ plateau. Few sands are represented in the Idfu & Armant ~ . ~ formation. ~ 10-Gabal Atawi area (C.E.D.) . :~ Zaki (1999), make geochemical exploration for rare earth ~ ~ elements at Gabal Atawi area (C.E.D). He found that the area AA was covered mainly by granitic rocks and drained by major .~ wadis trending N-S & E-W. The panning samples were collected ~ from alluvial deposits. The mineralogical studies of panning ;:~ samples show anomalous value for zirconium 22%, colombite ~ .~ 3%, cassiterite 2%, yetterium, 1 % anp. lanthanium 1 % in ~ concentrate. ;:~ I1-Gabal Mashbih and Korabkansi S.E.D. AA Bekhit. (1982), found that the gold, platinum and silver ~ minerals in the area between Gabal Mashbih and Korabkansi .:~ (S.E.D) of Egypt which is composed of schistose metavolcanics, ~ pyroclastics, serpentinite, tonalite, monzogranite, layored .~ gabbros, syenite and dyke system and have major faults NNlV ~~ ,.~ SSE & NE SW the gold minerals is confined mainly to Scvt'ral milky and smoky quartz veins cutting across the tonali te ;.~ intrusions and gold contents varies from 0.6 up to 106 glt the 00 ;.: .• , •• :. <. '.:. -,. '.: .• ,-~--{'i:':' platinum mineralization is associated mainly with serpentinite and layered gabbros and show values up to 4 ppm. Placer gold and platinum are recorded in stream sediment with ~. value up to 7ppm and 4ppm respectively. Silver is recorded with content up to 12g/t with other elements as AS,Cr, Ni, Co, Cu and Sn and few samples show the presence of Hg. They recommended further detailed explored for placer gold, silver platinum mineralized. 12-G.Mueilha (S.E.D.) Soliman (1981) writes that, from an economic point of view, the Gabal Mueilha area may be regarded as an important future reserve of placer cassitterite in Egypt. The geochemical rock sampling survey shows anomalies of, Sn, Nb, Pb, Mo, Bi & Be in the greisenized and albitized granites of Gabal Mueilha mass. Cassitterite shows irregular lateral & vertical distribution ~ in the alluvium but increase in concentration with depth 50 cm of the alluvium section. It is associated with the 10 to 80 mesh size of alluvium. Columbite, scheelite, thorite, monazite, xenotime, fluorite, topaz and zircon are usually associated -with cassitterite. Make geochemical surveys for Sn, Nb, Cu, and Au mineralization, Mueilha,Dungash area S.E.D. Egypt. Geocherrucal stream sediment and" bed rock surveys were carried out on area of about 400km2 in the Muelha Dungash area. Results indicated that Sn and Nb anomalies are •'N concentrated near Gabal Mueilha and are related to the greisenized and albitized granites. Disseminated type and vein type gold mineralization occur in propylitized granodiorites and quartz veins at Samut most Cu, Sn and Nb anomalies coincide with deep seated tectonic. Zones having the direction '''It or the Red Sea rift system. About 2933 samples were collected ~.: from the stream sediments in the Mueilha Dungash area at an average density of 7 samples per km. Sampling was carried out from the alluvium at about 20cm depth below the surface. Each sample is represented by about 200g of Imm fraction of the alluvium. (This size fraction of alluvium was found to be the most suitable for prospecting under conditions of S.E.D 13-Holnrit Mikpid and Muilha (S.E.D.). Soliman (1982) concluded that the Homrit Mikpid area consists of rare metal bearing graintes emplaced in tectonically action region and affected in some zones by autopneumatolysis including sodium metasomatism and greisenization. Greisens are devoid of beryllium minerals and contain cassiterite, columbite, topaz and fluorite. Beryl and chrysoberyl occur in the albitized & increase in amount with the increase in degree of sodium metasomatism fig. (geological map of Hormit Mikpid area). 1J1e accumulation of beryllium in the albitized granites and albitites is ascribed to increase in acidity due to the addition of sodium to the pneumatolytic solutions. Some of which are probably derived from greisens. 14- Abu Dabbab , Igla and Nuweibi (S.E.D.). Sabet (1976), found that cassiterite is the dominant heavy I::f:" mineral and also wolframite together with small amount of garnet, sphene, epidote, zircon, rutile, monazite, tantalite, columbite, magnetite and ilmenite. The area of the placer deposits is made up of geosynclinal metasedimentary formation cut by intrusive complexes different in age of composition including serpentinites, metagabbros• and epidiorite , grey granites , pink granite, apogranites and different varieties of ~:. dykes. The tin bearing quartz veins of Nuweibi and Abu Dabbab deposits, as well as, the tin tungsten deposit of Igla , are the' drifting source of the ore minerals. Both the mineralized veins ~. and the placer deposits are genetically related to the apogranites. The placer deposits of Abu Dabbab are situated in the upper reaches of Wadi Um Karia and Wadi Mubarak draining the veined zones and the apogranite massive. The placer of Igla deposits are mainly restricted to three Wadis, namely the main Wadi, the southern Wadi and the Northern Wadi Togetrer with a number of small tributaries that drain the stock work zone and I the veined tin tungsten deposits. Nuweibi placer is situated in the upper reaches of Wadi El Nabi El Atshan and is restricted to the central part of the Wadi Floor. 13-Holnrit Mikpid and Muilha (S.E.D.). Soliman (1982) concluded that the Homrit Mikpid area consists of rare metal bearing graintes emplaced in tectonically action region and affected in some zones by autopneumatolysis including sodium metasomatism and greisenization. Greisens are devoid of beryllium minerals and contain cassiterite, columbite, topaz and fluorite. Beryl and chrysoberyl occur in the albitized & increase in amount with the increase in degree of sodium metasomatism fig. (geological map of Hormit Mikpid area). 1J1e accumulation of beryllium in the albitized granites and albitites is ascribed to increase in acidity due to the addition of sodium to the pneumatolytic solutions. Some of which are probably derived from greisens. 14- Abu Dabbab , Igla and Nuweibi (S.E.D.). Sabet (1976), found that cassiterite is the dominant heavy I::f:" mineral and also wolframite together with small amount of garnet, sphene, epidote, zircon, rutile, monazite, tantalite, columbite, magnetite and ilmenite. The area of the placer deposits is made up of geosynclinal metasedimentary formation cut by intrusive complexes different in age of composition including serpentinites, metagabbros• and epidiorite , grey granites , pink granite, apogranites and different varieties of ~:. dykes. The tin bearing quartz veins of Nuweibi and Abu Dabbab deposits, as well as, the tin tungsten deposit of Igla , are the' drifting source of the ore minerals. Both the mineralized veins ~. and the placer deposits are genetically related to the apogranites. The placer deposits of Abu Dabbab are situated in the upper reaches of Wadi Um Karia and Wadi Mubarak draining the veined zones and the apogranite massive. The placer of Igla deposits are mainly restricted to three Wadis, namely the main Wadi, the southern Wadi and the Northern Wadi Togetrer with a number of small tributaries that drain the stock work zone and I the veined tin tungsten deposits. Nuweibi placer is situated in the upper reaches of Wadi El Nabi El Atshan and is restricted to the central part of the Wadi Floor. Sedimentology Soc. Egypt, Cairo, Egypt, 1998, v.6, p. 13 20. S E Desert; Wadi Allaqi; Abu Dabbab; Umm Samiuiki; S W Desert; Wadi Mueilha. lbrahim, MIM, 1995. Investigation of SOTI1e physical properties of zircon and futile to prepare high purity mineral concentrates from black sand deposits, Rossetta, Egypt. MSC Geol, Fac Sci, Mansoura Univ, 1995, 163p. Rossetta; N Med. coast. Mousa, BMM,. Abdel Ghafour, EA,. El- Shazly, MM, 1995. Mineralization and sedimentological studies in relation to genesis of some soils of the Eastern Coastal zone, Gulf of Suez, Sinai peninsula , Egypt . Ain shams SCI Bull ,Ain shams Univ. ,Cairo ,Egypt, 1995, v.33,p. 24-54. E g Suez coast; Wadi Feiran; W Sinai; Wadi Sudr; Ras Mohammed; Tor; Wadi Kalba; Wadi Wardan. Naim, GM,. Oweiss,KA Khalid, A,.Shaaban, Gj 8weissy, S,. Deif, A, 1996." Regional and geochemical exploration at a1 U waynat area. Niazy, EA, 1997. Size analysis and heavy minerals of the Wadi Feiran Pleistocene sediments, West Southern Sinai, Egypt. Egypt J Geol , 1997; vA1, no .2a ,427p. Wadi Feiran; W S Sinai; Gabal Mousa; Wadi El Sheikh; Wadi Solaf; Gabal Banat; Wadi El Akhdar; Nabbi Salih; Gabal Catherina. Overstreet, w.e. (1963): Regional Hearvy- Mineral Recconnaissance as a guide to one deposits in deoply weathered areas with semi-Humid to Humid, Temperate to tropic climate. U. S. geol. Suerv. 12, pp. 149- 162. Newyork Oweiss, KA, Said, MM, 1998. Geochemica1 exploration for gold at Gabal Madarai area, South Eastern Desert, Egypt. Ann Geol Surv Egypt, Cairo, Egypt, 1998, v. 21,p.225¬229. Sabet, A. H, Tsogoeu , V.B., Shibmanin , S.P. , El Kali, M.B., and Awad, S. (1976) : The placer tin deposits of Abu Dabbab , Igla and Nuweibi . Ann. Geol.surv. Egypt v.vi, pp. 169-180. bottom projections forming quiet eddies on the lee side.In these slack waters the heavy substances drop to the bottom.In streams, jigging action is effectiv~ in concentrating placer minerals in the bottom gravels. During dry seasons of low stream velocity the placer minerals remain at rest, but in flood time, the minerals and gravels may all swept farther downstream and reconcentrated on bars, stream margins of flood plains minute particles of gold called 'colors' may be carried far down stream. , , ~ , ~. Places of accumulaiiJ;, 7'/;)\ J lA? --7,; ~>
The lower sluggish reaches {hf stream and the upper headwaters
are not favoiiibfe- places ~f accumulation due to the limited ~l supply of source materials. The most favorable sites are the (l;f', middle reaches. Where streams ~rge " along polished L~(U\yon floors, placer minerals and gravels are rushed along with I itth~ ( opportunity for setting; but where they debauch into valley
" ---":>
section, of gentler gradient, the conditions are ideal for settling •
and concentration into deposits. In a rapidly flowing meandering stream the fastest water is on the outside curve of meanders, and slack water is opposite 9(fig2) the junction of the two, where
'gravels bars form, is a' favorable" site for deposition of placer minerals. Where streams cross highly inclined or vertically layered rocks, such as slate?, schists or alternating hard and soft beds, the harder layers tend to project up ward and the softer
ones to be cut away. This forms natural "riffles" (fig. b. ). 2'
These riffles are~xcellent traps for placer'9 minerals.When materials are delivered by ~ swi~ tributary into a slower master stream they accumulate, llilder diminished velocity as a pay streak down the near side. (fig. b ). If a stream crosses a f'r,1;'
mineralized lode a c-E.aystreak will be spread across the stream
channel on the downstream side of the lode (fig. ). Placer~'
accumulation requires-well-graded streams. Lindgreen considers that moderate gradients of around 30 feet per mile probably
yield the best concentration
Monday
reserch no rip
Sunday
types of mining"elmanga"
Placer mining involves any type of mining
where raw minerals are depostied in sand or gravel or on the surface and are picked up without having to drive, use dynamite or any other signifigant means. The word placer means "sand bank" in Spanish. Specific types of placer mining are panning, dredging, sluicing, using a Rocker, or just picking up what lies on the ground.
Hydraulic mining involves high pressure water.
The water is
Hardrock
Hardrock mining entails diging into solid rock to fine minerals usually in their ore form (the metal plus oxygen). To do this,
miners used picks and shovels, rock drills,
Open Pit
Hard rock mines usually fall into one of two categories, tunnels or shafts. Each involves digging and blasting deep into the bowels of the earth. Tunnel hard rock mines begin at the earth's surface
Tunnel Mine
Shafts
A shaft is a whole in the earth that is dug relatively straight down. Shafts usually have some sort of headframe or large wooden or metal structure at the top of the shaft to support a hoist. Hoists are used to lower men and machinery into the mine and to haul
Looking down a Shaft
In the early days and in small operations, simple mule and man power was used for everything. As technology advanced, and operations became larger, the steam engine was introduced.
A
Steam Engine
Water(Hydro) Power
Wherever possible, water or hydro power was used. If the location of the milling site was near any kind of sizeable reliable moving water, a water wheel would be used to generate power. This water wheel would have many paddles on it and would be partially submerged in moving water. As the water flowed, it would cause the wheel to turn. The wheel was then connected to whatever was needed to be powered.
Diesel Engines
In the early 1900's, diesel engines began to replace steam engines because they could produce more horsepower using less space. Invented by a man named Rudolph Diesel in 1894,
Diesel Engine
Once the ore was broken off the rock faces inside the mine, the chunks were shoveled into a transportation system to get it to the outside. If the mine was a shaft mine, the ore was shoveled into
Ore Bucket
Hoist
Ore Car
From the Mouth of the Mine to the Mill
Once the ore was at the mine entrance, it was transported to a mill for milling. The type of transportation used here depended on how far the mill was. Many mines had mills in the same town that were nearby the mine making transportation easy. Most of the time, ore was deposited into an ore chute that held tons of ore
Ore Chute
Aerial Tramway Tower
From the Mill on
Most mills were not able to concentrate the ore completely to the free metal. In other words, most mills located at the mines and townsites were not able to put a rock in one end and have a gold ingot 
When a full size stamp mill was not available, arrastras were used to crush the ore. Arrastras were small circular flat areas of land usually about 10-20 feet in diameter with a pole in the center.
Early Arrastra
Stamp Mills
Stamp Mills were far more advanced than the early arrastras although they both performed the same function. Stamp mills ranged from one stamp on up to twenty or even fifty stamps all operating together.
5 Stamp Mill
Small 3 Stamp Mill
