This study is focused on the biostratigraphy, sedimentary environments, facies distribution, and sequence stratigraphy of the Coniacian–Santonian sediments of Tange-Bulfaris section. Five assemblage zones have been recognized by distribution of the foraminifera in the study area. Assemblage zone 1(Chara Ostracods zone) is Coniacian in age and occurs in the lower part of the succession. Assembl...

  Introduction Identification of the climate changes is important for understanding the paleoenvironmental characteristics. Sedimentary evidence of the closed basins can be one of the most important methods for identifying the climatic periods and changes in the sedimentary environments. Gavkhouni Playa, as the lowland of the ZayandehRud River catchment area is located in an inter-mountainous...

Groundwater contaminated with arsenic (As) threatens the health of more than 140 million people worldwide. Previous studies indicate that geology and sedimentary depositional environments are important factors controlling groundwater As contamination. The Mississippi River delta has broadly similar geology and sedimentary depositional environments to the large deltas in South and Southeast Asia...

In the arid and semiarid environments of the world, microhabitats serve as models for the structure of vegetation communities. The goal of this study was to identify differences in the structures of the herbaceous communities growing on a crystalline substrate and those growing on a sedimentary substrate in a semiarid region of northeastern Brazil. One hundred 1 × 1 m plots were established in ...

Biogeochemical and stable carbon isotopic analysis of black-shale sequences deposited during an Albian oceanic anoxic event (approximately 112 million years ago) indicate that up to 80 weight percent of sedimentary organic carbon is derived from marine, nonthermophilic archaea. The carbon-13 content of archaeal molecular fossils indicates that these archaea were living chemoautotrophically. The...

Biologically active, fine-grained sediment forms abundant sedimentary deposits on Earth's surface, and mixed mud-sand dominates many coasts, deltas, and estuaries. Our predictions of sediment transport and bed roughness in these environments presently rely on empirically based bed form predictors that are based exclusively on biologically inactive cohesionless silt, sand, and gravel. This appro...