Fossilization of Precambrian microfossils in the Volyn pegmatite, Ukraine
<p>We report on Precambrian microfossils from igneous rocks of the Volyn pegmatite district, associated with the Paleoproterozoic Korosten pluton, northwestern Ukraine. The fossils were recovered from meter-sized miarolitic cavities and show a well-preserved 3D morphology, mostly filamentous b...
| Main Authors: | , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-03-01
|
| Series: | Biogeosciences |
| Online Access: | https://bg.copernicus.org/articles/19/1795/2022/bg-19-1795-2022.pdf |
| _version_ | 1819159024886611968 |
|---|---|
| author | G. Franz P. Lyckberg V. Khomenko V. Chournousenko H.-M. Schulz N. Mahlstedt R. Wirth J. Glodny U. Gernert J. Nissen |
| author_facet | G. Franz P. Lyckberg V. Khomenko V. Chournousenko H.-M. Schulz N. Mahlstedt R. Wirth J. Glodny U. Gernert J. Nissen |
| author_sort | G. Franz |
| collection | DOAJ |
| description | <p>We report on Precambrian microfossils from igneous rocks of the Volyn
pegmatite district, associated with the Paleoproterozoic Korosten pluton,
northwestern Ukraine. The fossils were recovered from meter-sized miarolitic
cavities and show a well-preserved 3D morphology, mostly filamentous but
with a large variety of types and also in irregular, flaky shapes
reminiscent of former biofilms, as well as rare spherical objects. Based on
literature data, pyrolysis experiments, and reflected light microscopy
results, the organic matter (OM) is characterized as (oxy-)kerite. Further
investigations with microscopic techniques, including scanning and
transmission electron microscopy, and electron microprobe analysis show that
fossilization likely occurred during a hydrothermal, post-pegmatitic event
by silicification dominantly in the outermost 1–2 <span class="inline-formula">µm</span> of the
microfossils. The hydrothermal fluid, derived from the pegmatitic
environment, was enriched in <span class="inline-formula">SiF<sub>4</sub></span>, Al, Ca, Na, K, Cl, and S. The OM
shows O enrichment in which N and S content is low, indicating simultaneous N
and S loss during anaerobic oxidation. Mineralization with Al silicates
starts at the rim of the microfossils, continuing in its outer parts into
identifiable encrustations and intergrowths of clay minerals, feldspar,
Ca sulfate, Ca phosphate, Fe sulfide, and fluorite.</p>
<p>Breccias, formed during collapse of some the miarolitic cavities, contain
decaying OM, which released high concentrations of dissolved <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><msub><mi mathvariant="normal">NH</mi><mn mathvariant="normal">4</mn></msub><mo>+</mo></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="29pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="47abf32743cd28df9573e01430c76658"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-19-1795-2022-ie00001.svg" width="29pt" height="14pt" src="bg-19-1795-2022-ie00001.png"/></svg:svg></span></span>,
responsible for the late-stage formation of tobelite-rich
muscovite and buddingtonite. The age of the fossils can be restricted to the time between the
pegmatite formation, at <span class="inline-formula">∼1.760</span> Ga, and the breccia formation
at <span class="inline-formula">∼1.49</span> Ga. As the geological environment for the growth of the
microorganisms and fossilization, we assume a geyser system in which the
essential biological components C, N, S, and P for growth of the organisms
in the miarolitic cavities were derived from microorganisms at the surface.
Fossilization was induced by magmatic <span class="inline-formula">SiF<sub>4</sub></span>-rich fluids. The Volyn
occurrence is a distinct and uncommon example of Precambrian fossils, and the
results underline the importance of cavities in granitic rocks as a possible
habitat for microorganisms preserved in the deep biosphere.</p> |
| first_indexed | 2024-12-22T16:33:59Z |
| format | Article |
| id | doaj.art-0b9b94d201e84d18be28b1f74939ac39 |
| institution | Directory Open Access Journal |
| issn | 1726-4170 1726-4189 |
| language | English |
| last_indexed | 2024-12-22T16:33:59Z |
| publishDate | 2022-03-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Biogeosciences |
| spelling | doaj.art-0b9b94d201e84d18be28b1f74939ac392022-12-21T18:20:00ZengCopernicus PublicationsBiogeosciences1726-41701726-41892022-03-01191795181110.5194/bg-19-1795-2022Fossilization of Precambrian microfossils in the Volyn pegmatite, UkraineG. Franz0P. Lyckberg1V. Khomenko2V. Chournousenko3H.-M. Schulz4N. Mahlstedt5R. Wirth6J. Glodny7U. Gernert8J. Nissen9Institut für Angewandte Geowissenschaften, Technische Universität Berlin, 10587 Berlin, GermanyLuxembourg National Museum of Natural History, 25 Rue Münster, 2160 Luxembourg, LuxembourgM.P. Semenenko Institute of Geochemistry, Mineralogy and Ore Formation, The National Academy of Sciences of Ukraine, 34, Palladina av., Kyiv, 03142, UkraineVolyn Quartz Samotsvety Company, Khoroshiv (Volodarsk-Volynski), UkraineSection 3.5: Interface Geometry, GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, GermanySection 3.5: Interface Geometry, GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, GermanySection 3.5: Interface Geometry, GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, GermanySection 3.5: Interface Geometry, GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, GermanyZentraleinrichtung Elektronenmikroskopie, Technische Universität Berlin, 10623 Berlin, GermanyZentraleinrichtung Elektronenmikroskopie, Technische Universität Berlin, 10623 Berlin, Germany<p>We report on Precambrian microfossils from igneous rocks of the Volyn pegmatite district, associated with the Paleoproterozoic Korosten pluton, northwestern Ukraine. The fossils were recovered from meter-sized miarolitic cavities and show a well-preserved 3D morphology, mostly filamentous but with a large variety of types and also in irregular, flaky shapes reminiscent of former biofilms, as well as rare spherical objects. Based on literature data, pyrolysis experiments, and reflected light microscopy results, the organic matter (OM) is characterized as (oxy-)kerite. Further investigations with microscopic techniques, including scanning and transmission electron microscopy, and electron microprobe analysis show that fossilization likely occurred during a hydrothermal, post-pegmatitic event by silicification dominantly in the outermost 1–2 <span class="inline-formula">µm</span> of the microfossils. The hydrothermal fluid, derived from the pegmatitic environment, was enriched in <span class="inline-formula">SiF<sub>4</sub></span>, Al, Ca, Na, K, Cl, and S. The OM shows O enrichment in which N and S content is low, indicating simultaneous N and S loss during anaerobic oxidation. Mineralization with Al silicates starts at the rim of the microfossils, continuing in its outer parts into identifiable encrustations and intergrowths of clay minerals, feldspar, Ca sulfate, Ca phosphate, Fe sulfide, and fluorite.</p> <p>Breccias, formed during collapse of some the miarolitic cavities, contain decaying OM, which released high concentrations of dissolved <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M3" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><msub><mi mathvariant="normal">NH</mi><mn mathvariant="normal">4</mn></msub><mo>+</mo></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="29pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="47abf32743cd28df9573e01430c76658"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="bg-19-1795-2022-ie00001.svg" width="29pt" height="14pt" src="bg-19-1795-2022-ie00001.png"/></svg:svg></span></span>, responsible for the late-stage formation of tobelite-rich muscovite and buddingtonite. The age of the fossils can be restricted to the time between the pegmatite formation, at <span class="inline-formula">∼1.760</span> Ga, and the breccia formation at <span class="inline-formula">∼1.49</span> Ga. As the geological environment for the growth of the microorganisms and fossilization, we assume a geyser system in which the essential biological components C, N, S, and P for growth of the organisms in the miarolitic cavities were derived from microorganisms at the surface. Fossilization was induced by magmatic <span class="inline-formula">SiF<sub>4</sub></span>-rich fluids. The Volyn occurrence is a distinct and uncommon example of Precambrian fossils, and the results underline the importance of cavities in granitic rocks as a possible habitat for microorganisms preserved in the deep biosphere.</p>https://bg.copernicus.org/articles/19/1795/2022/bg-19-1795-2022.pdf |
| spellingShingle | G. Franz P. Lyckberg V. Khomenko V. Chournousenko H.-M. Schulz N. Mahlstedt R. Wirth J. Glodny U. Gernert J. Nissen Fossilization of Precambrian microfossils in the Volyn pegmatite, Ukraine Biogeosciences |
| title | Fossilization of Precambrian microfossils in the Volyn pegmatite, Ukraine |
| title_full | Fossilization of Precambrian microfossils in the Volyn pegmatite, Ukraine |
| title_fullStr | Fossilization of Precambrian microfossils in the Volyn pegmatite, Ukraine |
| title_full_unstemmed | Fossilization of Precambrian microfossils in the Volyn pegmatite, Ukraine |
| title_short | Fossilization of Precambrian microfossils in the Volyn pegmatite, Ukraine |
| title_sort | fossilization of precambrian microfossils in the volyn pegmatite ukraine |
| url | https://bg.copernicus.org/articles/19/1795/2022/bg-19-1795-2022.pdf |
| work_keys_str_mv | AT gfranz fossilizationofprecambrianmicrofossilsinthevolynpegmatiteukraine AT plyckberg fossilizationofprecambrianmicrofossilsinthevolynpegmatiteukraine AT vkhomenko fossilizationofprecambrianmicrofossilsinthevolynpegmatiteukraine AT vchournousenko fossilizationofprecambrianmicrofossilsinthevolynpegmatiteukraine AT hmschulz fossilizationofprecambrianmicrofossilsinthevolynpegmatiteukraine AT nmahlstedt fossilizationofprecambrianmicrofossilsinthevolynpegmatiteukraine AT rwirth fossilizationofprecambrianmicrofossilsinthevolynpegmatiteukraine AT jglodny fossilizationofprecambrianmicrofossilsinthevolynpegmatiteukraine AT ugernert fossilizationofprecambrianmicrofossilsinthevolynpegmatiteukraine AT jnissen fossilizationofprecambrianmicrofossilsinthevolynpegmatiteukraine |