surface oil seeps from alasht, lapur and jenesem share many compositional affinities including distributions and concentrations ofnormal alkanes, terpanes and steranes. these oils also show many similarities with that of jurassic sediments (shemshak group, klarizformation) systematically sampled from the galandrud coal mine. recent geochemical studies in this area indicated that theshemshak gro...

surface oil seeps from alasht, lapur and jenesem share many compositional affinities including distributions and concentrations ofnormal alkanes, terpanes and steranes. these oils also show many similarities with that of jurassic sediments (shemshak group, klarizformation) systematically sampled from the galandrud coal mine. recent geochemical studies in this area indicated that theshemshak gro...

Dictyozamites barnardi sp. nov. and fakhri are the second third species of to be described from Iran Middle East. They derive Rhaetic Kalariz Formation (Shemshak Group) Ramsar area, Alborz Mountains, North Iran. is distinguished especially by short curved strongly falcate pinnae clearly auriculate bases particularly its long, slightly very elongated triangular pinnae, opposite sub position auri...

study of plant macrofossils of jurassic sediments of shemshak group in eshkevarat-e-olia areas led to identification of two species consisting lobifolia rotundifolia from ferns group (division pteridophyta & filicales order) and ptilophyllum vasekgahense from gymnospermae group (division cycadophyta & order bennettitales) that had been reported from rhaetian (late triassic) and dogger (middle j...

Surface oil seeps from Alasht, Lapur and Jenesem share many compositional affinities including distributions and concentrations ofnormal alkanes, terpanes and steranes. These oils also show many similarities with that of Jurassic sediments (Shemshak Group, KlarizFormation) systematically sampled from the Galandrud Coal Mine. Recent geochemical studies in this area indicated that theShemshak Gro...

1. introduction mountain regions are increasingly endangered by a variety of disaster, including avalanche, debris flows, and rock slide. some characteristics such as elevation, angle of slope, vegetation and climatic elements could affect the avalanche event. indeed, avalanche is the second factor in soil erosion that causes demolition; therefore, it threatens the food safety. iran has two mai...

This paper presents structural evidence of extensional activity in Central Alborz during Mesozoic. The structural evidence of homogenous early stage stretching such as layer-parallel to oblique boudinage of Permian and Triassic rocks in various portions of the study area accompanied by extensional-fibrous fractures were followed with more advanced extensional features. These extensional structu...