Growth of synthetic stromatolites and wrinkle structures in the absence of microbes - implications for the early fossil record.
Stromatolites and wrinkle structures are often taken to be an important indicator for early life. While both may be shaped by microbial mat growth, this can be open to doubt, so that the contribution of abiotic processes in their construction always needs to be established (Grotzinger and Knoll, 199...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
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2008
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| _version_ | 1797063288838684672 |
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| author | McLoughlin, N Wilson, L Brasier, M |
| author_facet | McLoughlin, N Wilson, L Brasier, M |
| author_sort | McLoughlin, N |
| collection | OXFORD |
| description | Stromatolites and wrinkle structures are often taken to be an important indicator for early life. While both may be shaped by microbial mat growth, this can be open to doubt, so that the contribution of abiotic processes in their construction always needs to be established (Grotzinger and Knoll, 1999). We here report laboratory spray deposition experiments that can generate stromatolites and wrinkle structures in the absence of microbes. These minicolumnar and sometimes branched stromatolites are produced artificially by the aggregation of a synthetic colloid in a turbulent flow regime. They self-organize at the relatively low particle concentrations found in the outer parts of a spray beam. This contrasts with adjacent stratiform deposits that are produced by high rates of colloid deposition and relatively low sediment viscosities found in the centre of a spray beam. These stratiform laminae become subsequently wrinkled during hardening of the colloid. These results support numerical models that together suggest that physicochemical processes are capable of generating laminated sedimentary structures without the direct participation of biology. Geological environments where comparable abiogenic stromatolites and wrinkle structures may be found include: splash-zone silica sinters, desert varnish crusts and early Archean cherts formed from silica gel precursors. |
| first_indexed | 2024-03-06T20:57:41Z |
| format | Journal article |
| id | oxford-uuid:39d20b44-d566-40ee-884c-f4d142d475c1 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:57:41Z |
| publishDate | 2008 |
| record_format | dspace |
| spelling | oxford-uuid:39d20b44-d566-40ee-884c-f4d142d475c12022-03-26T13:57:45ZGrowth of synthetic stromatolites and wrinkle structures in the absence of microbes - implications for the early fossil record.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:39d20b44-d566-40ee-884c-f4d142d475c1EnglishSymplectic Elements at Oxford2008McLoughlin, NWilson, LBrasier, MStromatolites and wrinkle structures are often taken to be an important indicator for early life. While both may be shaped by microbial mat growth, this can be open to doubt, so that the contribution of abiotic processes in their construction always needs to be established (Grotzinger and Knoll, 1999). We here report laboratory spray deposition experiments that can generate stromatolites and wrinkle structures in the absence of microbes. These minicolumnar and sometimes branched stromatolites are produced artificially by the aggregation of a synthetic colloid in a turbulent flow regime. They self-organize at the relatively low particle concentrations found in the outer parts of a spray beam. This contrasts with adjacent stratiform deposits that are produced by high rates of colloid deposition and relatively low sediment viscosities found in the centre of a spray beam. These stratiform laminae become subsequently wrinkled during hardening of the colloid. These results support numerical models that together suggest that physicochemical processes are capable of generating laminated sedimentary structures without the direct participation of biology. Geological environments where comparable abiogenic stromatolites and wrinkle structures may be found include: splash-zone silica sinters, desert varnish crusts and early Archean cherts formed from silica gel precursors. |
| spellingShingle | McLoughlin, N Wilson, L Brasier, M Growth of synthetic stromatolites and wrinkle structures in the absence of microbes - implications for the early fossil record. |
| title | Growth of synthetic stromatolites and wrinkle structures in the absence of microbes - implications for the early fossil record. |
| title_full | Growth of synthetic stromatolites and wrinkle structures in the absence of microbes - implications for the early fossil record. |
| title_fullStr | Growth of synthetic stromatolites and wrinkle structures in the absence of microbes - implications for the early fossil record. |
| title_full_unstemmed | Growth of synthetic stromatolites and wrinkle structures in the absence of microbes - implications for the early fossil record. |
| title_short | Growth of synthetic stromatolites and wrinkle structures in the absence of microbes - implications for the early fossil record. |
| title_sort | growth of synthetic stromatolites and wrinkle structures in the absence of microbes implications for the early fossil record |
| work_keys_str_mv | AT mcloughlinn growthofsyntheticstromatolitesandwrinklestructuresintheabsenceofmicrobesimplicationsfortheearlyfossilrecord AT wilsonl growthofsyntheticstromatolitesandwrinklestructuresintheabsenceofmicrobesimplicationsfortheearlyfossilrecord AT brasierm growthofsyntheticstromatolitesandwrinklestructuresintheabsenceofmicrobesimplicationsfortheearlyfossilrecord |