This is a draft Articles for creation (AfC) submission. It is not currently pending review. While there are no deadlines, abandoned drafts may be deleted after six months. To edit the draft click on the "Edit" tab at the top of the window.
If you need help editing or submitting your draft, please ask us a question at the AfC Help Desk or get live help from experienced editors. These venues are only for help with editing and the submission process, not to get reviews.
If you need feedback on your draft, or if the review is taking a lot of time, you can try asking for help on the talk page of a relevant WikiProject. Some WikiProjects are more active than others so a speedy reply is not guaranteed.
To improve your odds of a faster review, tag your draft with relevant WikiProject tags using the button below. This will let reviewers know a new draft has been submitted in their area of interest. For instance, if you wrote about a female astronomer, you would want to add the Biography, Astronomy, and Women scientists tags.
Tasmanites is a planktonic prasinophytealgae in the division Chlorophyta. First described by the renowned botanist Joseph Dalton Hooker in 1852, Tasmanites was named after its initial discovery in oil shales from Tasmania, Australia. Hooker’s fascination with the fossilized remains of this algae stemmed from their unusual preservation and their potential to unlock the secrets of ancient ecosystems. His work not only highlighted the role of microscopic algae in geological processes but also established a foundation for using microfossils to understand Earth's history.
Later studies in the 19th century by geologist E. T. Newton expanded on Hooker's findings, referring to Tasmanites as white coal, a nod to its significance in the emerging field of petroleum geology. Since then, Tasmanites has been recognized for its critical role in forming oil shale deposits and its contributions to understanding paleontology and petroleum geology.
Fossils of Tasmanites are found in a wide range of geological settings, including Permian and Triassic deposits, making it a valuable tool for reconstructing past environments and evaluating hydrocarbon resources.[1][2][3]
Tasmanites is classified within the green algae division (Chlorophyta) and is specifically grouped in the class Prasinophyceae. This class comprises both modern and fossil prasinophytes. Tasmanites is unique as a fossil prasinophyte and lacks modern analogs, making it important for studying ancient algal evolution.[3][1]
Tasmanites cells, known as phycomata, vary in size from 30–600 μm in diameter, with larger specimens found in Permian and Triassic deposits, such as those in Svalbard and West Timor.[4] The lipid-rich cell walls, reinforced with radial silica structures, enhance fossilization in marine and lacustrine environments, making Tasmanites a key contributor to type-I and type-II kerogens in hydrocarbon source rocks.
Joseph Dalton Hooker, the botanist who first described Tasmanites algae in 1852.
First described by Joseph Dalton Hooker in 1852 and further classified by E. T. Newton in 1875, Tasmanites is now identified as a prasinophyte cyst , belonging to the Chlorophyta phylum . It is enriched in tricyclic terpanes with distinct δ13C signatures, providing valuable data for geochemical analyses.[5]Tasmanites is typically identified through palynological methods, which use acid treatment to dissolve the mineral matrix of host rocks, isolating organic components. This technique allows researchers to study cellular structures in detail, offering insights into ancient environments and organic sedimentation.[6]
Tasmanites played a vital role in ancient marine ecosystems as a planktonicgreen algae belonging to the Prasinophyceae class. Thriving in nearshore, nutrient-rich environments during the Permian and Triassic, its high adaptability allowed it to colonize diverse settings, from cold polar seas to warm equatorial basins. This adaptability indicates its importance in primary productivity, particularly in stratified water columns where nutrient availability supported algal blooms.[1][3][7]
Furthermore, Tasmanites coexisted with other marine organisms, such as foraminifera and radiolarians, within the photic zone. These interactions formed the base of trophic networks, where organic matter derived from Tasmanites supported heterotrophic species, enhancing overall biodiversity in marine ecosystems.[5][8]
The hydrocarbon-generating potential of Tasmanites has made it a key contributor to petroleum geology. Rich in lipids and highly resistant to degradation, its fossilized remains contribute to type-I and type-II kerogens in oil shale deposits. Notable examples include the Permian oil shales of Tasmania and the Triassic deposits of the Barents Sea, both of which are vital resources in hydrocarbon exploration.[2][9][4]
Its preserved lipid-rich cell walls are chemically unique, generating high-quality liquid hydrocarbons upon thermal maturation. Consequently, Tasmanites-dominated deposits are globally significant as markers of high petroleum potential, particularly in ancient marine basins with favorable preservation conditions, such as anoxia or suboxia. This economic relevance underscores the genus's importance in understanding global energy resources.[10][11]
Tasmanites fossils provide a window into early algal evolution and the role of phytoplankton in ancient carbon cycles. As one of the few well-preserved fossil representatives of the Prasinophyceae, it offers critical insights into the adaptation of primitive algae to fluctuating paleoenvironments. Palynological analyses reveal its cellular structures and lipid composition, providing essential data on paleoenvironmental conditions such as salinity, temperature, and oxygen availability.[12][13]
The genus also serves as a paleoecological indicator of depositional environments, with its presence highlighting anoxic basins, shallow marine shelves, or lacustrine systems during periods of high organic productivity.[14][15] The interactions of Tasmanites with sedimentary processes and its contribution to sedimentary organic matter are crucial in reconstructing basin histories and global climatic events such as glacial cycles.[16][17]
Moreover, Tasmanites has contributed to our understanding of mass extinctions, as its abundance often correlates with periods of ecological stress and high organic productivity, such as the Permian-Triassic boundary.[2][14]
Tasmanites thrived in nearshoremarine environments, typically in shallow, cold seas with varying salinity. These habitats were often characterized by high nutrient availability, driven by upwelling currents or glacial meltwater, creating favorable conditions for algal blooms. The algae's adaptability allowed it to inhabit a diverse range of environments, from high-latitude regions to equatorial settings.
Depositional environments were generally anoxic to suboxic, where limited oxygen restricted organic decay, preserving Tasmanites in sedimentary deposits. Such conditions were common in restricted marine basins, fjord, and large lacustrine systems. Over geological time, these settings facilitated the accumulation of organic-rich sediments, which transformed into hydrocarbon-rich shales.[3]
Diagram illustrating an anoxic basin environment, showing the halocline layer and deep hypersaline conditions that limit organic decay, aiding in the preservation of Tasmanites in sedimentary deposits.
Tasmanites Bloom and Oil Shale Formation: Diagram showing Tasmanites blooms and oil shale formation driven by freshwater injection during deglaciation.
Key processes in organic matter sedimentation: algal production in the photic zone, lateral transport, and microbial reprocessing.
In addition to its ecological adaptability, Tasmanites serves as a valuable indicator of paleoenvironmental conditions. Its occurrence in sedimentary rocks is often associated with periods of elevated organic productivity and nutrient influx, such as glacial retreats or deglaciation events. Specific examples include:
* Permian Deposits: In Tasmania, Tasmanites dominated deposits formed in cold, nutrient-rich marine environments during the Late Paleozoic Ice Age.[3]
* Triassic Deposits: In Svalbard and the Barents Shelf, Tasmanites indicates deposition in subpolar shallow seas characterized by periodic anoxia.[1]
* Equatorial Lakes: In the Junggar Basin of northern Pangea, Tasmanites reflects lacustrine environments with warm, equatorial conditions and limited oxygen exchange.[10]
Globally, Tasmanites fossils are distributed across diverse paleogeographic settings, ranging from high-latitude regions such as Svalbard to equatorial environments like West Timor and the Junggar Basin in China. This widespread occurrence highlights the adaptability of Tasmanites to various marine environments, making it a valuable indicator for reconstructing paleoenvironmental conditions and analyzing sedimentary basins.[1]
The fossil record of Tasmanites extends from the Precambrian to the Cenozoic, with peak abundance recorded during the Permian and Triassic periods.[1][4] Evidence from younger deposits suggests that Tasmanites persisted in certain environments beyond the Triassic, showcasing its adaptability and survival through various geologic epochs.[2]
This map highlights major geological formations where Tasmanites-rich deposits have been extensively studied and are of significant geological or economic importance. It does not represent the complete global distribution of Tasmanites occurrences, as the genus has been found in a much wider range of environments around the world. Instead, the focus is on regions where Tasmanites is a dominant component of organic-rich rock formations, such as oil shales.
Major rock formations with significant Tasmanites fossils
^ abcdefgVigran, J. O., et al. (2008). Tasmanites algae—contributors to the Middle Triassic hydrocarbon source rocks of Svalbard and the Barents Shelf". Polar Research, 27(3), 360–371. Cite error: The named reference "Vigran2008" was defined multiple times with different content (see the help page).
^ abcdeNewton, E. T. (1875). "On “Tasmanite” and Australian “White Coal”". Geological Magazine, 2(8), 337–342. Cite error: The named reference "Newton1875" was defined multiple times with different content (see the help page).
^ abcdefgRevill, A. T., et al. (1994). "Hydrocarbon biomarkers, thermal maturity, and depositional setting of tasmanite oil shales from Tasmania, Australia". Geochimica et Cosmochimica Acta, 58(18), 3803–3822. Cite error: The named reference "Revill1994" was defined multiple times with different content (see the help page).
^ abcLelono, E. B. (2019). "The Gondwanan Green Alga Tasmanites sp. in the Permian Lacustrine Deposits of West Timor". Indonesian Journal on Geoscience, 6(3), 255–266. Cite error: The named reference "Lelono2019" was defined multiple times with different content (see the help page).
^ abcGreenwood, P. F., Arouri, K. R., & George, S. C. (2000). "Tricyclic terpenoid composition of Tasmanites kerogen as determined by pyrolysis GC-MS". Geochimica et Cosmochimica Acta, 64(7), 1249–1263. Cite error: The named reference "Greenwood2000" was defined multiple times with different content (see the help page).
^Guy-Ohlson, D. (1988). "Developmental stages in the life cycle of Mesozoic Tasmanites". Review of Palaeobotany and Palynology, 54(1–2), 1–9.
^Stewart, K. D., & Mattox, K. R. (1984). "The case for a polyphyletic origin of mitochondria: morphological and molecular comparisons". Journal of Molecular Evolution, 21, 54–57. [DOI: 10.1007/BF02101798](https://doi.org/10.1007/BF02101798)
^ abKroeck, D. M., Mullins, G., Zacaï, A., Monnet, C., & Servais, T. (2022). "A review of Paleozoicphytoplankton biodiversity: Driver for major evolutionary events?". Earth-Science Reviews, 232, 104113. [DOI: 10.1016/j.earscirev.2022.104113](https://doi.org/10.1016/j.earscirev.2022.104113)
^Neto, F. A., Trigüis, J., Azevedo, D. A., Rodrigues, R., & Simoneit, B. R. T. (1992). "Organic geochemistry of geographically unrelated Tasmanites". Organic Geochemistry, 18(6), 791–803. [DOI: 10.1016/0146-6380(92)90101-6](https://doi.org/10.1016/0146-6380(92)90101-6)
^Parke, M., Boalch, G. T., Jowett, R., & Harbour, D. S. (1978). "The genus Pterosperma (Prasinophyceae): species with a single equatorial ala". Journal of the Marine Biological Association of the United Kingdom, 58(1), 239–276. [DOI: 10.1017/S0025315400024701](https://doi.org/10.1017/S0025315400024701)
^Liu, S., Misch, D., Gang, W., Li, J., Jin, J., Duan, Y., & Fan, K. (2023). "Evaluation of the tight oil “sweet spot” in the Middle Permian Lucaogou Formation (Jimusaer Sag, Junggar Basin, NW China): Insights from organic petrology and geochemistry". Organic Geochemistry, 177, 104570. [DOI: 10.1016/j.orggeochem.2022.104570](https://doi.org/10.1016/j.orggeochem.2022.104570)
Pangaea on Wikipedia – Overview of the supercontinent where Tasmanites fossils were distributed.
Permian Period on Wikipedia – Information on the Permian period, a time of high Tasmanites abundance.
Oil shale on Wikipedia – Discussion on how Tasmanites contributes to oil shale deposits and hydrocarbon resources.
