Soil stabilization by a prokaryotic desert crust: Implications for Precambrian land biota

Details Soil stabilization by a prokaryotic desert crust: Implications for Precambrian land biota Soil stabilization by a prokaryotic desert crust: Implications for Precambrian land biota

Sep 1979

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1979orli....9..335c&link_type=abstract

Origins of Life, Volume 9, Issue 4, pp.335-348

Computer Science

13

Scientific paper

A cyanophyte dominated mat, desert crust, forms the ground cover in areas measuring hundreds of square meters in Utah and smaller patches in Colorado. The algal mat shows stromatolitic features such as sediment trapping and accretion, a convoluted surface, and polygonal cracking. Sand and clay particles are immobilized by a dense network of filaments of the two dominating cyanophyte species,Microcoleus vaginatus andM. chthonoplastes, which secrete sheaths to which particles adhere. These microorganisms can tolerate long periods of desiccation and are capable of instant reactivation and migration following wetting. Migration occurs in two events: 1. immediately following wetting of dry mat, trichomes are mechanically expelled from the sheath as it swells during rehydration, and 2. subsequently, trichomes begin a self-propelled gliding motility which is accompanied by further production of sheath. The maximum distance traveled on solid agar by trichomes ofMicrocoleus vaginatus during a 12 hour period of light was 4.8 cm. This corresponds to approximately 500 times the length of the fastest trichome, and provides a measure of the potential for spreading of the mat in nature via the motility of the trichomes. Dehydration resistence of the sheath modifies the extracellular environment of the trichomes and enables their transition to dormancy. Following prolonged wetting and evaporative drying of the mat in the laboratory, a smooth wafer-like crust is formed by the sheaths ofMicrocleus trichomes that have migrated to the surface. Calcium carbonate precipitates among the algal filaments under experimental conditions, indicating a potential for mat lithification and fossilization in the form of a caliche crust. It is suggested that limestones containing tubular microfossils may, in part, be of such an origin. The formation of mature Precambrian soils may be attributable to soil accretion, stabilization, and biogenic modification by blue-green algal land mats similar to desert crust.

Affiliated with

Also associated with

No associations

Rating

Soil stabilization by a prokaryotic desert crust: Implications for Precambrian land biota does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Soil stabilization by a prokaryotic desert crust: Implications for Precambrian land biota, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Soil stabilization by a prokaryotic desert crust: Implications for Precambrian land biota will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1820079