Deformation of ooids by compaction in the Precambrian Bhander Limestone, India: Implications for lithification

Abstract

Research Article| November 01, 1977 Deformation of ooids by compaction in the Precambrian Bhander Limestone, India: Implications for lithification S. K. CHANDA; S. K. CHANDA 1Department of Geological Sciences, Jadavpur University, Calcutta 700032, India Search for other works by this author on: GSW Google Scholar AJIT BHATTACHARYYA; AJIT BHATTACHARYYA 1Department of Geological Sciences, Jadavpur University, Calcutta 700032, India Search for other works by this author on: GSW Google Scholar SOUMEN SARKAR SOUMEN SARKAR 1Department of Geological Sciences, Jadavpur University, Calcutta 700032, India Search for other works by this author on: GSW Google Scholar Author and Article Information S. K. CHANDA 1Department of Geological Sciences, Jadavpur University, Calcutta 700032, India AJIT BHATTACHARYYA 1Department of Geological Sciences, Jadavpur University, Calcutta 700032, India SOUMEN SARKAR 1Department of Geological Sciences, Jadavpur University, Calcutta 700032, India Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1977) 88 (11): 1577–1585. https://doi.org/10.1130/0016-7606(1977)88<1577:DOOBCI>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation S. K. CHANDA, AJIT BHATTACHARYYA, SOUMEN SARKAR; Deformation of ooids by compaction in the Precambrian Bhander Limestone, India: Implications for lithification. GSA Bulletin 1977;; 88 (11): 1577–1585. doi: https://doi.org/10.1130/0016-7606(1977)88<1577:DOOBCI>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Nodules of silicified oomicrite (chert) occur in the upper part of the shallow-water Precambrian Bhander Limestone of central India. The nodules characteristically are surrounded by aureoles, elongated parallel to bedding, of plastically deformed ooids. Both the intensity of deformation and packing density of the ooids in the limestone decrease away from the rigid nodules until a point is reached where there is neither detectable deformation nor condensation (intensification of "closeness" of grains). Lack of pervasive deformation in the limestone is interpreted to suggest that although in places compaction-deformation began early in diagenesis, cementation also began almost simultaneously, preventing the process from affecting the sediment beyond the limits of the aureoles.Deformation of allochems, particularly nonductile ones, appears to be possible only under unusually intense overburden pressure (or shear stress). Anomalously high stress around rigid nodules of precompaction origin may lead, however, to the deformation of allochems at much lower overburden pressures, and therefore earlier than normally possible. Whereas the presence of deformed allochems proves compaction, the converse may not be true. Sediments do compact, but overburden pressure probably does not normally exceed the load-bearing capacity of the allochems; in such cases, allochems would not be visibly deformed. Within the normal range of lithostatic pressure likely in compaction, sutured micrite fabric and condensation of allochems are therefore more likely than deformed allochems. Cementation may commonly intervene before sufficient overburden pressure is built up to deform allochems. Overemphasis on the presence of deformed allochems as a sign of compaction appears to have overshadowed the importance of compaction in the diagenetic evolution of limestones. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.