Nutrient-triggered bioerosion on a giant carbonate platform masking the postextinction Famennian benthic community

The influence of terrestrial run off on marine biotic communities: An example from a thrust-top carbonate ramp (Upper Pennsylvanian foreland basin, Picos de Europa, NW Spain)

“…Hallock (1988) demonstrated that in modern mesotrophic waters close to river mouths and in marine areas affected by currents of nutrient-rich waters (e.g., from the Mississippi delta to western and southern Florida), carbonate sand and gravel exhibiting biological alteration are abundant. Also Peterhänsel and Pratt (2001) postulated that the increase in the effects of bioeroders (skeletal micritization and bioerosion) in the Late Devonian carbonate platform of the Palliser Formation (Canadian Rocky Mountains) was linked to an increase in nutrient supply.…”

“…Moreover, constructional microbial encrustation and micritic envelopes forming cortoids, aggregates, which also contributed to the genesis of oncoids, is a further indicator for high nutrient levels (Peterhänsel and Pratt, 2001). 4) The dark colour characterizing the autochthonous carbonate deposits of the Las Llacerias Formation seems to have resulted from a high amount of non-degraded organic matter present within the sediments and visible in many thin sections (Figs.…”

Sampling-standardized expansion and collapse of reef building in the Phanerozoic

“…Sea-level changes are thus unlikely to be directly responsible for this reef crisis. A nutrient-triggered crisis due to landplant evolution (Algeo & Scheckler 1998;Peterhånsel & Pratt 2001) would well explain why reefs were especially affected while the general extinction intensity was moderate (Foote 2001). The Carboniferous and Per-mian periods exhibit modest fluctuations and even the end-Permian mass extinction did not result in a reef decline that could not be explained by changes in sampling (Fig.…”

“Calcispheres” as a source of lime mud and peloids – evidence from the early Middle Devonian of the Prague Basin, the Czech Republic

“…Pratt 2001, Stieglitz 1972, and disintegration of benthic calcareous algae (Coniglio & James 1985, Lowenstam 1955, Lowenstam & Epstein 1957, Neumann & Land 1975, Stockmann et al 1967. Formation of mud due to the carbonate grain diminution via micritization processes was discussed by Bathurst (1966), Klement & Toomey (1967), Perkins & Halsey (1971), Peterhänsel & Pratt (2001), Swinchat (1965), Tudhope & Risk (1985) and Young & Nelson (1988). Lime mud formation due to the erosion and abrasion of micritized grains (micritization sensu Alexandersson 1972) was described by Reid et al (1992).…”

“…Lime mud formation due to the erosion and abrasion of micritized grains (micritization sensu Alexandersson 1972) was described by Reid et al (1992). Many of the mechanisms of micrite formation described from modern environments probably also took place in ancient environments, e.g., microbially mediated precipitation (for review see, e.g., Monty 1995, Riding 2000, diminution of grains due to the activity of microborers (Klement & Toomey 1967, Peterhänsel & Pratt 2001, or disintegration of calcareous algae (Coniglio & James 1985) or calcified cyanobacteria (Pratt 2001). …”