a stratigraphic section from the tirgan formation was selected in arkan village nearby bojnourd city in order to study echinoderm fauna systematically. many specimens of echinoderms, especially toxasteridae which is associated with brachiopods were collected and studied systematically in this paper. microscopie slides were also prepared and studied. all slides contain benthic foraminifers and c...

the investigated section cropping out in kuh-e-banesh, zagros basin (southern iran) is represented by limestone, cherty beds and marllevels bearing abundant planktonic foraminifers, radiolarian microfaunas, and ammonite imprints. for the first time, well to moderatelypreserved forms of planktonic foraminifera have been extracted from black shale and marls levels. extracted biota was studied wit...

Current carbon and sulphur isotope ratios (δ(13)C and δ(34)S) suggest there were major shifts in partitioning between reduced and oxidised reservoirs of carbon and sulphur during the Early Cretaceous. However, the δ(13)C and δ(34)S records are composed from different Ocean Drilling Program sites and are hard to correlate at high resolution. We present high-resolution Aptian δ(13)C(org) and δ(34...

The Arrifes section (Algarve Basin, Southern Portugal) has been studied from the viewpoint of charophyte biostratigraphy. previous sedimentological studies in this showed that it is built interbedding continental and marine facies contain both palynomorphs (pollen, spores, dinoflagellates), providing an excellent sedimentary context to perform direct correlations between domains. In present wor...

Superplumes have been put forward as a driving mechanism for a variety of global phenomena, ranging from geomagnetic reversal anomalies to global climate warming via massive additions of volcanic CO2. Here I propose that rates of uplift caused by modern superplumes would result in the liberation of hundreds of Gt of carbon from methane clathrates on a timescale from tens to hundreds of millions...

Abstract. The Early Cretaceous is characterized by warm background temperatures (i.e., greenhouse climate) and carbon cycle perturbations that are often marked ocean anoxic events (OAEs) associated shifts in the hydrologic cycle. Higher-resolution records of terrestrial marine δ13C δ18O (both carbonates organics) suggest climate during Aptian–Albian, including a period with OAE 1a early Aptian ...

Abstraet The amount and type of organic matter present in an exceptionally complete upper Aptian to lower Cenomanian sequence of sediments from ODP site 763 on the Exmouth Plateau has been determined. Organic carbon concentrations average 0.2~o. Organic matter is marine in origin, and its production and preservation was low over the ca. 20-million-year interval recorded by this sequence. Becaus...