STRATIGRAPHY AND TRILOBITE FAUNAS FROM THE CAMBRIAN BURJ FORMATION 



133 



AGE 



(after 



JORDAN 



Lloyd, 1969;Selley, 1970,-Powell, 1988 

 Masn, 1988) 



KUSHSHA 

 SANDSTONE 



FM 



MUDAWWARA 



SANDSTONE 



FM 



DUBEIDIB 

 SANDSTONE 



FM. 



Ratiya Sst Mbr 



Batra Mst Mbr. 



Tubeiliyat Sst. 

 Mbr. 



HISWAH SANDSTONE 



UMM SAHM SANDSTONE 

 FM. 



DISI SANDSTONE 



UMM ISHRIN SANDSTONE 



Hanneh \Kusheiba 

 Siltstone N — ? s < . 



SALIB ARKOSE FM 



A Q A B A 



C M P L EX 



TIMNA (ISRAEL) 

 (Weissbrod, 1970) 



NETAFIMFM 

 SHEHORETFM 



Mikhrot Mbr 



Nehushtan Mbr 



Nimra Mbr. 



AMUDEI SHELOMO FM 



PRE- CAMBRIAN BASEMENT 



Fig. 1 Slraligraphical framework of the Cambrian and Ordovician rocks 

 in Jordan and Israel (after Powell, 1989). 



Bender (1974) termed it the 'dolomite-limestone-shale formation' 

 and followed the definition of Blanckenhorn (op. cit.). However, in 

 lithological sections and maps Bender (1968) included about 30 

 metres of overlying shales and sandstone (cb 2+1 ) within the same 

 formation. The latter definition was adopted by Powell ( 1 988) and is 

 followed here, although in the subsurface Andrews (1991) placed 

 the top of the formation at the top of the Numayri Dolomite. Powell 

 recognised three members, in upwards sequence: theTayan Siltstone, 

 Numayri Dolomite and Hanneh Siltstone, described below, from the 

 type area near Safi (Figs 3-5). 



The Burj Formation is equivalent to theTimna Formation (Fig. 1 ) 

 on the west side of theWadi Araba, atTimna, near Eilat (Weissbrod, 

 1970). The four formations of Parries' (1971) review -the Hakhlil, 

 Nimra, Nehushtan and Mikhrot formations - are here treated as 

 members of the Timna Formation. 



Tayan Siltstone Member. This ranges in thickness from 1 8-20m, 

 and consists of finely laminated green, mauve and red or buff, 

 micaceous, fine-grained sandstone and siltstone. 



The name is taken from Wadi Tayan (PNG 201 .5:061.5) where the 

 member is well exposed (Figs 3, 5). Straight-crested, oscillation 

 (wave) ripples, ripple cross-lamination, and parallel lamination are 

 common. The thicker sandstone beds have small-scale, bimodal, 

 trough cross-bedding with mudstone intraclasts. Thin dolomite 



lenses are present near the middle of the member, and indeterminate 

 surface burrows are common on some bedding planes. Secondary 

 gypsum veins and laminae occur along joints and bedding planes. 

 The lower boundary is defined at the base of mauve-red micaceous 

 siltstone and fine-grained sandstone that overlies yellow-brown 

 medium-grained trough cross-bedded sandstone of the Salib Arkose 

 Formation. The upper junction with the Numayri Dolomite is taken 

 at the base of the first thick bed of limestone or dolomitic limestone, 

 which in places is sandy, with low-angle erosive scours and ripple 

 cross-lamination. 



Numayri Dolomite Member. The member (38 to 60 m thick) 

 forms a prominent, brown-weathering cliff along the outcrop. The 

 name derives from Wadi Numayri (PNG 203:059) where it is well 

 exposed. The carbonate varies from limestone to dolomitic lime- 

 stone and dolomite with wackestone and packstone textures; clasts 

 include ooliths and bioclasts (brachiopods, hyolithids and trilo- 

 bites). The vertical sequence of microfacies varies throughout the 

 outcrop, but the following generalised sequence is common to most 

 exposures in the Safi -Wadi Numayri areas: the basal 5 m has a high 

 proportion of fine-grained quartz sand with ripple cross-lamination 

 and sandstone intraclasts; this passes up to a massive, brown- 

 weathering (grey) dolomite and dolomitic limestones 

 (microcrystalline, wackestone and packstone textures), 20-30 m 

 thick, with glauconite peloids, cross-laminated and parallel-lami- 

 nated oolites, oncolites (algal-coated grains), and lenses of 

 disarticulated brachiopods and rare trilobite fragments. Irregular 

 lenses of orange-brown dolomite are intercalated with the clast-rich 

 carbonates. There is an increase in quartz sand above, with alternat- 

 ing sand-rich and sand-poor lenses; the sand-rich lenses are 

 cross-laminated, with shallow erosive scours and they weather as 

 prominent dark brown chert-like bands, 2-3 m thick. Beds of oolitic, 

 oncolitic or brachiopod shell-rich dolomicrite limestone are locally 

 present at the top of the member in the south. Near Safi (Figs 4, 5), 

 the member is thicker (58 m) and the upper part includes beds of 

 cross-laminated oolitic limestone, algal stromatolites, and thin (40 

 cm) beds of green calcareous siltstone with abundant trilobite 

 fragments, hyolithids and glauconite peloids. Here, the sequence is 

 capped by a distinctive orange-weathering dolomite. The textures 

 and fine details of the carbonates are often obscured at outcrop by 

 ubiquitous brown staining. The boundary with the green, red or grey 

 micaceous siltstone or fine-grained sandstone of the overlying 

 Hanneh Siltstone is sharp. 



Hanneh Siltstone Member. The name is taken from Jibal Tabaq 

 Hanneh (PNG 201.5:060.0), on the north side of Wadi Numayri 

 (Fig. 3). The lithology of this member is similar to the Tayan 

 Siltstone, but there is a higher proportion of sand over silt-grade 

 siliciclastic rocks. It was not previously included in the formation, 

 except for the maps and lithological sections in Bender ( 1968). It is 

 about 30 m thick in the Wadi Saramuj area and 35 m thick in the cliffs 

 below Jibal Tayan. The base is sharp, and is taken where red-grey or 

 green parallel-laminated to ripple cross-laminated micaceous 

 siltstone overlies the carbonate (Numayri Dolomite). The beds 

 above are laterally variable, but predominantly comprise thinly 

 bedded green or red-green, micaceous, ripple cross-laminated 

 siltstone and micaceous fine-grained sandstone, with thicker beds 

 (0.5 m) of buff, medium-grained, bimodal trough cross-bedded 

 sandstone; mudstone and dolomite clasts are common at some 

 horizons. Small, circular surface-burrows and Rusophycus(l) traces 

 are present on siltstone surfaces. The top is clearly marked by the 

 overlying red-brown, massive, medium- to coarse-grained, large- 

 scale trough cross-bedded sandstone (Umm Ishrin Formation). 



