Definition of "stromatolite"

stromatolite

noun
plural stromatolites
1. (geology) A laminated, columnar, rock-like structure constituting a large share of all fossils from 3.5 to 0.5 billion years ago, with some still being formed at present, some or all of which result from the deposit of minerals by microorganisms such as cyanobacteria.
  Quotations
  Most modern and ancient stromatolites occur in carbonate sediments and sedimentary rocks, but they can form by trapping and binding of any sediment particles.
  1979, D. G. Lundgren, W. Dean, “Chapter 4: Biogeochemistry of Iron”, in P. A. Trudinger, D. J. Swaine, editors, Biogeochemical Cycling of Mineral-Forming Elements, page 232
  Stromatolites are the predominant features of carbonate rocks formed in Precambrian oceans.
  2003, David M. Paterson, Rebecca J. Aspden, R. Pamela Reid, Biodynamics of Modern Marine Stromatolites, Andrew H. Knoll, Life on a Young Planet: The First Three Billion Years of Evolution on Earth, page 44
  The formation of modern stromatolites is highly dependent on sediment accretion rates and their associated microbial assemblages that trap and bind sediment particles that fall on the surface of the structures.
  2010, Joseph Seckbach, Aharon Oren, editors, Microbial Mats: Modern and Ancient Microorganisms in Stratified Systems, page 231