Dinoflagellate cysts from the Upper Bajocian–Lower Oxfordian of the Dalichai Formation in Binalud Mountains (NE Iran): their biostratigraphical and biogeographical significance

The Binalud Mountains of NE Iran represent the easternmost extension of the Alborz Range. After the Mid-Cimmerian orogenic event and rapid subsidence, the deep marine sediments of the Dalichai Formation were deposited. A well-preserved section of the formation was sampled for palynological purposes. The study revealed diverse and nearly well-preserved dinoflagellate cyst assemblages. Thirty-six dinoflagellate cyst species identified lead to identification of four biozones: Cribroperidinium crispum (Late Bajocian), Dichadogonyaulax sellwoodii (Bathonian to Early Callovian), Ctenidodinium continuum (Early to Late Callovian), and Ctenidodinium tenellum (Early Oxfordian) biozones. The close similarities of dinoflagellate cyst assemblages between Binalud Mountains, NE Iran, with those of Alborz Mountains (Northern Iran) during Middle Jurassic confirm the connection between two sedimentary basins during this time in Iran. Meanwhile, this biozonation corresponds largely to that established in Northwest Europe and reveals the marine connection between NE and North of Iran with Northwest Europe and the Northwestern Tethys during the Late Bajocian to Early Oxfordian.     

TECHNICAL NOTE. Model study of H-piles subjected to combined loading

A series of model tests on H-piles subject to lateral and vertical loading have been performed so that the experimental data could be used to calibrate a finite element programme. Experiments on model H-piles in dry silca sand were performed to determine the influence of lateral displacements on the vertical load-carrying capacity of the piles. The results from the nonlinear finite element computer program were compared to the experimental results and were found to be conservative. The experimental results showed greater pile capacities and lower bending moments than were predicted by the finite element program.     

Frequency-Magnitude Relationships for seismic areas around the capital cities of Solomon, Vanuatu, Tonga and Fiji Islands

We studied the relationships between the frequency ofoccurrence and the magnitudes in seismogenic areasthat will affect four capital cities in the SouthPacific, namely: Honiara in Solomon Islands, Port Vilain Vanuatu, Suva in Fiji and Nuku'alofa in Tonga. Weused the NEIS catalogues for the period 1973–1997, formagnitudes greater than about 5, in the proximity tothe city under investigation. The definitions of thegeographic boundaries of the seismogenic zones arebased on the classical concepts of the distribution ofthe tectonic plates, the overwhelming number ofstudies that describe the seismotectonics in thoseactive regions and on the observed seismicity andstudies of the local people. Completeness of thecatalogue is assumed because of the high seismicity inthese areas, despite the relatively short time span.We have used a hybrid process combining least squaresfitting and Newtonian search process to find the bestfit of the statistical parameters. The characteristicb value is 1.27, and seems to be irrespective of thedepth and/or region.