Conglomerate (geology)#Fanglomerate

A Fanglomerat (English fan " fan", lat conglomerare " piling together ", also arid boulder clay, occasionally: Schlammbrekzie ) is formed in arid regions of clastic sedimentary rocks.

In terms of its structure characteristics is the rock between a conglomerate and a breccia, since it contains both weakly rounded and angular components ( clasts ), which can range from 1.2 m diameter Schluffgröße up to blocks. The so characteristic of sedimentary rock microstructure features such as grading and stratification are missing almost entirely, as a sorting according to grain size. The rock contains much coarse material and very little fine-grained matrix as a binder.

Fanglomerat can be considered as diagenetic deposition of solidified debris of one or more delivery areas (hills, mountains and other high areas) of the area, which explains its heterogeneous ( polymictic ) composition of different rock components. Due to the short transport distances, the components are barely sorted and rounded. The rock is a typical formation of arid regions ( deserts and semi-deserts ), the transport of the constituents found only rare, but abundant rainfall, climate typical Stark or jerk rain, instead, the fan-like spread that over the long dry periods accumulated rock material in sheet flow. Fanglomerates are characteristic of alluvial fan formations in wadis.

Fossil fanglomerates are known for example from the Permian to Triassic Verrucano the Alps. Other occurrences of such rocks are found in the Rotliegend and Zechstein about the Baden-Baden trough in Baden -Württemberg, in the Permian of the Oslo trench or in the Waderner layers of the Permian of the Saar -Nahe Valley.