Subaqueous Gravity Processes on the Front of Cretaceous Deltas, Recôncavo Basin, Brazil

Research Article| May 01, 1972 Subaqueous Gravity Processes on the Front of Cretaceous Deltas, Recôncavo Basin, Brazil GEORGE deVRIES KLEIN; GEORGE deVRIES KLEIN Department of Geology, University of Illinois, Urbana, Illinois 61801--Petróleo Brasileiro S.A. (DIREX-JIQUITAIA) Ave. Frederico Search for other works by this author on: GSW Google Scholar UBIRAJARA deMELO; UBIRAJARA deMELO Pontes No. 220, Edf. Hamilton Lopes, Salvador, Bahia, Brazil Search for other works by this author on: GSW Google Scholar JORGE CARLOS DELLA FAVERA JORGE CARLOS DELLA FAVERA Pontes No. 220, Edf. Hamilton Lopes, Salvador, Bahia, Brazil Search for other works by this author on: GSW Google Scholar GSA Bulletin (1972) 83 (5): 1469–1492. https://doi.org/10.1130/0016-7606(1972)83[1469:SGPOTF]2.0.CO;2 Article history received: 16 Jun 1971 rev-recd: 22 Nov 1971 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation GEORGE deVRIES KLEIN, UBIRAJARA deMELO, JORGE CARLOS DELLA FAVERA; Subaqueous Gravity Processes on the Front of Cretaceous Deltas, Recôncavo Basin, Brazil. GSA Bulletin 1972;; 83 (5): 1469–1492. doi: https://doi.org/10.1130/0016-7606(1972)83[1469:SGPOTF]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 Delta-front sedimentation dominated deposition of the Cretaceous Pitanga Member of the Candeias Formation and the Caruaçu Beds of the Marfim Formation, Recôncavo Basin, Brazil. The Pitanga Member is subdivided into three sedimentary facies according to differences in lithology and sedimentary structures, whereas the Caruaçu Beds are subdivided into ten such facies.The three sedimentary facies of the Pitanga Member are (1) Disrupted Sandstone-Mudstone Facies, containing slump fragments, pull-aparts, and small-scale faults and folds deposited by slumping and sliding as a cohesive sediment; (2) Massive Sandstone Facies, poorly sorted sandstones containing dispersed clasts of coarse sand, granules, and mudstone blocks deposited by mass flow and slurrying during cohesion loss; and (3) Dish-structured Sandstone Facies; poorly sorted sandstones with dish structures and steplike load structures deposited by grain flow.The ten facies of the Caruaçu Beds were deposited in distributary channels (Quartzose Sandstone Facies; Micro–cross-laminated Facies), interdistributary bays (Parallel-laminated Mudstone Facies), delta fronts and delta-front troughs by subaqueous slumping as cohesive sediment (Disturbed Sandstone-Mudstone Facies, Pebbly Mudstone Facies), mass flowand slurrying due to cohesion loss (Massive Sandstone Facies), and grain flow (Dish-structured Sandstone Facies, Conglomerate Facies). These facies can be grouped into a delta-plain association, a high delta-front association (slump dominated) and a low delta-front trough association (massflow, slurry, and grain-flow dominated). Their areal distribution indicates both southward progradation of the deltas and repeated slumping.Triggering mechanisms of subaqueous slumping, mass flow and grain flow in this example include growth faulting, slope instability in response to local diapiric upwarp, and loading of water-saturated muddy sediments with overlying sand and gravel transported over short distances by high-gradient streams. Deposition occurred predominantly in delta-front troughs. 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.