Archaeological and soil-stratigraphic data define the origin, growth, and collapse of Subir, the third millennium rain-fed agriculture civilization of northern Mesopotamia on the Habur Plains of Syria. At 2200 B. C., a marked increase in aridity and wind circulation, subsequent to a volcanic eruption, induced a considerable degradation of land-use conditions. After four centuries of urban life, this abrupt climatic change evidently caused abandonment of Tell Leilan, regional desertion, and collapse of the Akkadian empire based in southern Mesopotamia. Synchronous collapse in adjacent regions suggests that the impact of the abrupt climatic change was extensive.

/pdf/the-genesis-and-collapse-of-third-millennium-north-571k0ray8h.pdf

The Genesis and Collapse of Third Millennium North Mesopotamian Civilization

http://envismadrasuniv.org/Microbes%20and%20Radionuclide%20Pollution/pdf/The%20removal%20of%20uranium.pdf

The removal of uranium from mining waste water using algal/microbial biomass

An early soda ocean

Eastern Turkish high plateau as a small Turkic-type orogen: Implications for post-collisional crust-forming processes in Turkic-type orogens

MICROBIALITES are organosedimentary deposits produced by benthic microbial communities interacting with detrital or chemical sediments1. Calcareous cyanobacterial microbialites defined as stromatolites and thrombolites were common in ancient shallow marine environments2. Today, they are restricted to a few lacustrine and perimarine settings. This restriction may result from changes in seawater chemistry through time3–6, particularly from alteration in supersaturation with respect to carbonate minerals7. The largest known calcareous microbialites (several metres high) were formed in the late Precambrian8. Here we report the discovery of enormous (∼40 m high) tower-like microbialites from alkaline (pH>9.7) Lake Van, eastern Anatolia. Growth is by mats of coccoid cyanobacteria (Pleurocapsa group) permineralizing in situ with aragonite and by inorganically precipitated calcite. Certain aspects of these microbialites resemble Proterozoic marine stromatolites9.

Largest known microbialites discovered in Lake Van, Turkey

Lake Van is a lake with a volume of 607 km3 and a maximum depth of 451 m in a tectonically active zone in eastern Anatolia. It may be divided into three physiographic provinces: lacustrine shelf, sublacustrine slope and lake basin. The shelf is largely made up of submerged fluvial valleys and alluvial plains, as evidenced by the local occurrence of karst-like topography, buried, leveed river valleys and sediment wedges interpretable as relict deltas. The shelf and basinal deposits are characterized by an alternating succession of well-stratified and chaotically reflecting layers consisting of turbidites and slump deposits respectively. This thick sequence of unconsolidated to consolidated sediments is underlain by a Paleozoic metamorphic or Upper Cretaceous limestone basement.

A geological study of lake van, Eastern Turkey

Environmental parameters responsible for the fixation of uranium in recent sediments: test area bow lake, ontario, canada. part i.

The organic matter in the Late Cretaceous and Tertiary sediments from the southern Black Sea margin is assigned to the terrestrial-marine/terrestrial range of organic facies. Within this range, the stratigraphic section yields different organic facies types in response to different accumulation and preservation controlling processes. During the Late Companian-Maastrichtian, organic material from the shelf and slope was re-deposited in the deeper oxic parts of the basin. Rapid transport and sedimentation resulted in a higher degree of preservation of lipid-rich, terrestrial components (sporinite, cutinite, resinite) in comparison to the autochthonous sediments. The increase in organic carbon with increasing silt/clay content together with low carbon concentrations in the allochthonous sediments suggest that the accumulation of organic matter in the source areas was controlled by terrigenous influx and that the accumulation conditions were not favorable.

H. K. Wong

Papers

A geological study of lake van, Eastern Turkey

Environmental parameters responsible for the fixation of uranium in recent sediments: test area bow lake, ontario, canada. part i.

Provenance and diagenesis of organic matter in Late Cretaceous and Tertiary sediments from the southern Black Sea margin