{"title":"岩石Rinds和砂/淤泥涂层中的古环境档案","authors":"W. Mahaney","doi":"10.1086/703537","DOIUrl":null,"url":null,"abstract":"Organo-mineral chemical coatings in rock rinds and sands and silts, underappreciated research until recently, offer a wealth of paleoenvironmental records derived from chemical and biomineral weathering over varying time frames. Rock rinds as well as sands and silts in paleosols carry various detailed records ranging from thin weathered films in young (Holocene) samples to thicker, often overprinted records in recycled sands/rinds of Pleistocene and older age, some as old as Miocene and Late Oligocene. Whereas rinds on Earth are confined to the Late Paleogene/Neogene, similar examples on Mars extend into the Noachian (∼4 Ga). New research outlined here shows that coatings tend to produce altered microsurfaces conducive to microbe growth with fossil forms found in a variety of different microenvironments, including extreme polar and tropical locales. Organo-chemical coatings on sands in paleosols reveal a wealth of biomarkers important in paleoenvironmental reconstruction from pole to equator. Rock rinds, revealed here, are shown to carry weathering zones in microcosm that often bear a close similarity to juxtaposed paleosols, the latter carrying mature A/B/C/Cu horizonation, indicating that weathering forces affecting a substrate are fine-tuned to similar kinetic forces acting on clasts in surface deposits. Aeolian and cosmic airburst inputs to rock rinds and chemical reconstruction of Si/Al wreckages leading to clay mineral reconstruction are also found in some rind and paleosol records. Analyses of such coatings using the light microscope, scanning electron microscope/energy dispersive spectrometer, focused ion beam, and secondary ion mass spectrometer offer the prospect of revealing still more secondary organo-mineral compounds, whose relation to primary mineral weathering is of importance to understanding pedogenic and diagenetic processes. The sum total of environmental change over time, written or embedded in rinds and sand/silt coatings, when subjected to high-resolution microscopy offers a novel mineral archive at the nanometer level and above.","PeriodicalId":54826,"journal":{"name":"Journal of Geology","volume":null,"pages":null},"PeriodicalIF":1.5000,"publicationDate":"2019-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1086/703537","citationCount":"3","resultStr":"{\"title\":\"Paleoenvironmental Archives in Rock Rinds and Sand/Silt Coatings\",\"authors\":\"W. Mahaney\",\"doi\":\"10.1086/703537\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Organo-mineral chemical coatings in rock rinds and sands and silts, underappreciated research until recently, offer a wealth of paleoenvironmental records derived from chemical and biomineral weathering over varying time frames. Rock rinds as well as sands and silts in paleosols carry various detailed records ranging from thin weathered films in young (Holocene) samples to thicker, often overprinted records in recycled sands/rinds of Pleistocene and older age, some as old as Miocene and Late Oligocene. Whereas rinds on Earth are confined to the Late Paleogene/Neogene, similar examples on Mars extend into the Noachian (∼4 Ga). New research outlined here shows that coatings tend to produce altered microsurfaces conducive to microbe growth with fossil forms found in a variety of different microenvironments, including extreme polar and tropical locales. Organo-chemical coatings on sands in paleosols reveal a wealth of biomarkers important in paleoenvironmental reconstruction from pole to equator. Rock rinds, revealed here, are shown to carry weathering zones in microcosm that often bear a close similarity to juxtaposed paleosols, the latter carrying mature A/B/C/Cu horizonation, indicating that weathering forces affecting a substrate are fine-tuned to similar kinetic forces acting on clasts in surface deposits. Aeolian and cosmic airburst inputs to rock rinds and chemical reconstruction of Si/Al wreckages leading to clay mineral reconstruction are also found in some rind and paleosol records. Analyses of such coatings using the light microscope, scanning electron microscope/energy dispersive spectrometer, focused ion beam, and secondary ion mass spectrometer offer the prospect of revealing still more secondary organo-mineral compounds, whose relation to primary mineral weathering is of importance to understanding pedogenic and diagenetic processes. The sum total of environmental change over time, written or embedded in rinds and sand/silt coatings, when subjected to high-resolution microscopy offers a novel mineral archive at the nanometer level and above.\",\"PeriodicalId\":54826,\"journal\":{\"name\":\"Journal of Geology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.5000,\"publicationDate\":\"2019-06-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1086/703537\",\"citationCount\":\"3\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Geology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1086/703537\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"GEOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Geology","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1086/703537","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOLOGY","Score":null,"Total":0}
Paleoenvironmental Archives in Rock Rinds and Sand/Silt Coatings
Organo-mineral chemical coatings in rock rinds and sands and silts, underappreciated research until recently, offer a wealth of paleoenvironmental records derived from chemical and biomineral weathering over varying time frames. Rock rinds as well as sands and silts in paleosols carry various detailed records ranging from thin weathered films in young (Holocene) samples to thicker, often overprinted records in recycled sands/rinds of Pleistocene and older age, some as old as Miocene and Late Oligocene. Whereas rinds on Earth are confined to the Late Paleogene/Neogene, similar examples on Mars extend into the Noachian (∼4 Ga). New research outlined here shows that coatings tend to produce altered microsurfaces conducive to microbe growth with fossil forms found in a variety of different microenvironments, including extreme polar and tropical locales. Organo-chemical coatings on sands in paleosols reveal a wealth of biomarkers important in paleoenvironmental reconstruction from pole to equator. Rock rinds, revealed here, are shown to carry weathering zones in microcosm that often bear a close similarity to juxtaposed paleosols, the latter carrying mature A/B/C/Cu horizonation, indicating that weathering forces affecting a substrate are fine-tuned to similar kinetic forces acting on clasts in surface deposits. Aeolian and cosmic airburst inputs to rock rinds and chemical reconstruction of Si/Al wreckages leading to clay mineral reconstruction are also found in some rind and paleosol records. Analyses of such coatings using the light microscope, scanning electron microscope/energy dispersive spectrometer, focused ion beam, and secondary ion mass spectrometer offer the prospect of revealing still more secondary organo-mineral compounds, whose relation to primary mineral weathering is of importance to understanding pedogenic and diagenetic processes. The sum total of environmental change over time, written or embedded in rinds and sand/silt coatings, when subjected to high-resolution microscopy offers a novel mineral archive at the nanometer level and above.
期刊介绍:
One of the oldest journals in geology, The Journal of Geology has since 1893 promoted the systematic philosophical and fundamental study of geology.
The Journal publishes original research across a broad range of subfields in geology, including geophysics, geochemistry, sedimentology, geomorphology, petrology, plate tectonics, volcanology, structural geology, mineralogy, and planetary sciences. Many of its articles have wide appeal for geologists, present research of topical relevance, and offer new geological insights through the application of innovative approaches and methods.