statistical studies on palynology contents of late cretaceous to paleocene age gurpi formation in a surface section in zagros basin,sw iran indicate changes in abundance, species diversity, ratio of spiniferites to cyclonephelium (s/c), palynological marine index(pmi) values and organic facies. these palynological variations clearly reflect fluctuations in relative sea-level and depositionalenv...

in the area sw of arak, intrusives are emplaced into metasediments of early mesozoic age. the intrusive rocks vary in morphology, structure and mineralogy, and exhibit various degrees of alterations; rb-sr geochronological data have been obtained to constrain their timing. there are three different groups of granitic rocks in the area: (a) the astaneh intrusion, consisting of granite, biotite g...

The early Eocene greenhouse world was marked by multiple transient hyperthermal events. The most extreme was the Paleocene-Eocene Thermal Maximum (PETM, ~56 Ma), linked to the extinction of the globally recognised deep-sea benthic foraminiferal Velasco fauna, which led to the development of early Eocene assemblages. This turnover has been studied at high resolution, but faunal development into ...

The construction and destruction of mountain belts exert a first-order control in ecosystems by creating bridges barriers for populations, modifying river-drainage networks local regional climate patterns. Several questions including How tectonics topographic growth decay what is the thermal geological record decay? remain unclear are subject extensive research. Here we use data from Antioquia ...

the study of tectonic evolution of the tethyan and se asian regions indicates that these tworegions have each passed through southwardly progressing sequences of similar tectonic events. both regionshave experienced a southward island-arc subduction and back-arc spreading leading to continentaldetachment from gondwanaland, with an earlier southward island arc subduction of palaeotethys (tethyan...

Data from four DNA regions (rbcL, matK, 26S rDNA, and ITS) as well as extant and fossil morphology were used to reconstruct the phylogeny and biogeographic history of an intercontinentally disjunct plant group, the cornelian cherries of Cornus (dogwoods). The study tests previous hypotheses on the relative roles of two Tertiary land bridges, the North Atlantic land bridge (NALB) and the Bering ...

The Paleogene carbonate deposits of Pabdeh and Jahrum formations are widespread from the northwest (Dashte Zari area) to southwest Shahrekord region in High Zagros Mountains Iran record lateral upward transition open marine into shallow water environment. Formation shows a succession pelagic hemipelagic limestone, argillaceous chert. It consists planktonic wackestone, pellet-planktonic mudstone...

Extensional processes can lead to complex crustal configuration depending on the mechanisms of lithospheric thinning and impact magmatic additions during rifting breakup. In this context, we studied Vøring volcanic passive margin offshore Norway. The evolution inner Margin is well explained by standard models lithosphere extension. However, these fail reproduce key observations at outer (volcan...

The current sedimentological and petrographical research of the Abbottabad Formation has been carried out in order to understand formation evolution Proto-Tethys Ocean during Cambrian on northern margin Indian Plate. Muzaffarabad region is located east Upper Indus Basin southern part Hazara Kashmir Syntaxis. geological history varies from Precambrian recent period. well exposed along Syntaxis a...

The tectonic opening of the Tasmanian Gateway and Drake Passage represented crucial geographic requirements for Cenozoic development Antarctic Circumpolar Current (ACC). Particularly complexity has hampered exact dating deepening phases, consequential onset throughflow ACC. One obstacles is putting key regional events, recorded in southern Patagonian sediments, absolute time. For that purpose, ...