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southern flank of the Elboorz Chain, where it generally rests upon 

 shale and red sandstone, which is underlaid by a calcareous forma- 

 tion, called by the author, mountain limestone. To the east of 

 Teheran, the lithographic stone extends nearly to the village of De- 

 mavend. 



Sandstone and Coal. — Between Teheran and Demavend, a sand- 

 stone of a coal formation is occasionally exposed ; and in the bed 

 of the river, Dalee Chaee, are upraised beds of " altered shale, like 

 coked coal." On the north side of the Elboorz Mountains, shale and 

 sandstone, assigned to the same coal deposit, are exposed resting 

 upon the limestone. At Abbassabad is a sandstone, but it is not stated 

 whether it belongs to this formation. A sandstone resting on lime- 

 stone occurs in the ravine through which the Heraz flows above 

 Amol ; also on the summit of the limestone pass between Karoo and 

 Bulkulum. About a mile below the latter village, a precipice 900 or 

 1000 feet high consists of perpendicular beds of coal and sandstone, 

 but on the opposite bank of the river the sandstone strata are nearly 

 horizontal. 



Limestone. — Strata, considered by Dr. Bell as the representatives 

 of the mountain limestone, constitute the hills to the S.E. of Teheran, 

 and overhang the ruined city of Rai. To the westward of Dema- 

 vend, the range of mountains, both north and south of the road as 

 far as the Caravanserai of Dalee Chaee, consist of the same limestone 

 resting on trap. Above the Caravanserai of Ameenabad, it occurs rest- 

 ing also on trap ; and the hills in the neighbourhood of the plain of 

 Feroozkooh are similarly constituted. Onthenorth side of the Elboorz 

 chain — a coal- shale and sandstone rest on this limestone. Below Pul-i- 

 SefFeed, the Talar runs for a considerable distance through a gorge 

 presenting perpendicular cliffs of beds of limestone and conglome- 

 rate. Limestone, resting on trap, also occurs in the ravine south of 

 Amol. In ascending the river beyond this ravine towards Karoo, the 

 following section is exposed. Trap — limestone — sandstone — shale 

 — indurated slate clay — buhrstone — sandstone — limestone — trap. 

 Between Karoo and Bulkulum is a narrow and deep fissure through 

 a mountain of limestone, capped by the coal strata ; and near the 

 tomb of Em Zadeh Hashim, limestone again occurs resting on trap. 



Organic Remains. — In the superficial conglomerate near the Dalee 

 Chaee Caravanserai, Dr. Bell observed portions of two small Ammo- 

 nites imbedded in fragments of compact limestone, but he did not 

 notice the same rock in situ*. 



Trap. — Greenstone, basalt, amygdaloid, porphyry, claystone, 

 pitchstone, and serpentine, underlie the limestone at many places. 



Travertine. — Springs charged with calcareous matter were often 

 noticed, and it is stated, that the preservation of the remains of 

 Shah Abas's causeway is owing to the calcareous drippings from the 



* Near the summit of the ridge of the Elboorz just below the snowline, 

 south of the district Toonikaban, he found a limestone containing bivalve 

 shells ; and near Bayazeed, in the neighbourhood of Mount Azarat, lime- 

 stone inclosing corals and oysters, and resting on sandstone. 



