Looking for any information concerning corals form deltaic or deltaically influenced areas - both from fossil and recent record. I'm mainly interested in solitary corals.
There are several reports concerning fossil and modern scleractinian corals in brackish environments. You may check:
Försterra & Häussermann (2003). First report on large scleractinian (Cnidaria: Anthozoa) accumulations in cold-temperate shallow water of south Chilean fjords. Zoologische Verhandelingen (Leiden) 345: 117-128.
Pandey et al. (2002). The oldest Jurassic cyathophorid coral (Scleractinia) from siliciclastic environments of Kachchh Basin, western India. Paläontologische Zeitschrift 76 (2): 347-356.
Beside this, pennatulacean octocorals are more common in such tidal deltaic environments.
solitary corals are reported from Middle Jurassic Lajas Formation of Neuquen Basin, Argentina.
MORSCH, S. M. . Scleractinian corals of Neuquen Basin (Lower Jurassic), Argentina. Bull.Tohoku Univ. Museum, Osaka,
v. 1, p. 320-332, 2001.
MORSCH, S. M. . Les Scléractiniaires jurassiques (Bajocien) d'Argentine (Bassin de Neuquén). I Systématique. Geobios, Villeurbanne, v. 29, n. 6, p. 671-706, 1996.
The attached paper of Martinez 2002 list a lot of references on Lajas Formation.