The aims of this study were (1) to review the spring zooplankton versus autumn zooplankton of a shallow polymictic
lake; (2) to assess how much the zooplankton of the transition seasons, i.
The basin is underlain by Clarkie Formation epiclastic rocks; greywacke, siltstone, polymictic
conglomerate and iron formation.
Therefore, the analysis focused on the identification of altered components on the surface of the grains and the general geochemical classification of fragments, which may indicate either an origin from a common source or a polymictic
character of the bulk of the ash.
The most characteristic feature of the Cisna Beds is the occurrence of grey (grey-brown on weathered surfaces), thick-bedded (even more than 3m), fine-to coarse-grained, polymictic
sandstones with calcareous-siliceous cement (so-called Cisna-type sandstones).
This influence might occur especially in Lake Chapala, which is a shallow, polymictic
, and turbid lake where suspended montmorillonite clays may enhance conditions for the bacteria by providing a surface for the adsorption, photodegradation, and desorption of dissolved organic carbon (Tietjen et al.
Phytoplankton community of a polymictic
reservoir, La Plata River basin, Uruguay.
Conglomerate is commonly polymictic
, displaying subangular, sub-rounded and angular clasts up to 8 cm across of local basement rock lithologies; granodiorite, diorite, and quartzite are especially common.
The water column is frequently mixed and the lakes are therefore referred to as polymictic
The Fuenteobejuna section is 140 m thick, mostly composed of limestones, shales and polymictic
breccias in the upper part.
The lake belongs to the polymictic
type of lakes, where complete mixture of the water body takes place several times a year.
Water temperature of the lake followed air temperature rather closely, the circulation pattern was continuum warm polymictic
, and no thermal stratification was recorded.
Two small, shallow and polymictic
reservoirs near to Curitiba city (Parana State, Brazil), were studied.