Blue‐green algae and terrestrial limestone weathering on Aldabra Atoll: An S.E.M. and light microscope study
Author(s) -
Viles H. A.
Publication year - 1987
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.3290120310
Subject(s) - atoll , weathering , algae , geology , landform , calcite , geochemistry , oceanography , ecology , geomorphology , biology , reef
Abstract Blue‐green algae have been observed to affect limestone weathering on Aldabra Atoll, Indian Ocean. Three different habitats can be identified on the rock surface, i.e. epilithic, chasmolithic, and endolithic. Algae in each habitat may affect weathering in various ways. Samples of blue‐green algae and rock were taken from various terrestrial and coastal environments on Aldabra Atoll. Samples of limestone tablets and calcite crystals after one year in situ were also studied. Light and S.E.M. microscopy revealed that endolithic boreholes were present on many samples, especially those from frequently wetted sites, to a maximum depth of 800 μm. An ‘altered zone’ of micrite and algal filaments was also discovered in many samples. From morphological and petrographical evidence blue‐green algal influences on weathering on Aldabra Atoll seem to be very complex and cannot easily be related to small scale landforms.