Rare preservation of Triassic pedorelicts with biogenic traces from a hot semi-arid upland palaeoenvironment at Portishead, SW England

Invited comments on Kirkham’s ‘Glauconitic spherules from the Triassic of the Bristol Area, SW England: probable microtektite pseudomorphs’

Kirkham describes some ‘glauconitic’ spherules found in the Bristol area of SW England. He lists several possible origins for the spherules, including volcanic, but concludes that they are probably of impact origin. He does not, however, discuss why the other possible origins do not explain the observations. Although the spherules do exhibit features similar to some Cretaceous–Tertiary (K–T) bo...

A gigantic nothosaur (Reptilia: Sauropterygia) from the Middle Triassic of SW China and its implication for the Triassic biotic recovery

The presence of gigantic apex predators in the eastern Panthalassic and western Tethyan oceans suggests that complex ecosystems in the sea had become re-established in these regions at least by the early Middle Triassic, after the Permian-Triassic mass extinction (PTME). However, it is not clear whether oceanic ecosystem recovery from the PTME was globally synchronous because of the apparent la...

Solar Radiation Estimation from Rainfall and Temperature Data in Arid and Semi-arid Climates of Iran

Precipitation and air temperature data, only, are often recorded at meteorological stations, with radiation beingmeasured at very few weather stations, especially in developing countries. Therefore there arises a need for suitablemodels to estimate solar radiation for a completion of data sets. This paper is about an evaluation of eight models foran estimation of daily solar radiation (Q) from ...

Soils of Arid and Semi-arid Areas

Carbon losses by tillage under semi-arid Mediterranean rainfed agriculture (SW Spain)

Conservation tillage has been promoted as a solution to counteract constraints caused by intensive agriculture. In this work the effects of two conservation tillage systems, reduced tillage (RT) and no-tillage (NT) were compared to the traditional tillage (TT) in a long(15 years, RT) and short-term experiment (3 years, NT). Both experiments were carried out under semi-arid, rainfed agriculture ...