scholarly journals Tectonic control on sedimentary facies pattern and sediment accumulation rates in the Miocene foreland basin of the southern Alborz mountains, northern Iran

Tectonics ◽  
2008 ◽  
Vol 27 (6) ◽  
pp. n/a-n/a ◽  
Author(s):  
Paolo Ballato ◽  
Norbert R. Nowaczyk ◽  
Angela Landgraf ◽  
Manfred R. Strecker ◽  
Anke Friedrich ◽  
...  
Keyword(s):  
Sediment Accumulation ◽  
Foreland Basin ◽  
Sedimentary Facies ◽  
Accumulation Rates ◽  
Northern Iran ◽  
Tectonic Control

scholarly journals Holocene Paleohydrology of the Tropical Andes from Lake Records

1997 ◽  
Vol 47 (1) ◽  
pp. 70-80 ◽  
Author(s):  
Mark B. Abbott ◽  
Geoffrey O. Seltzer ◽  
Kerry R. Kelts ◽  
John Southon
Keyword(s):  
Time Series ◽  
Late Pleistocene ◽  
Sediment Accumulation ◽  
Sedimentary Facies ◽  
Accumulation Rates ◽  
Tropical Andes ◽  
Abrupt Increase ◽  
Middle Holocene ◽  
Abrupt Changes ◽  
Cordillera Real

AbstractTwo century-scale time series in northern Bolivia constrain the ages of abrupt changes in the physical, geochemical, and biological characteristics of sediments obtained from lakes that formed during deglaciation from the late Pleistocene glacial maximum. The watersheds of Laguna Viscachani (16°12′S, 68°07′W, 3780 m) and Lago Taypi Chaka Kkota (16°13′S, 68°21′W, 4300 m), located on the eastern and western slopes of the Cordillera Real, respectively, contain small cirque glaciers. A high-resolution chronology of the lake sediments is provided by 23 AMS14C dates of discrete macrofossils. Late Pleistocene glaciers retreated rapidly, exposing the lake basins between 10,700 and 970014C yr B.P. The sedimentary facies suggest that after 890014C yr B.P. glaciers were absent from the watersheds and remained so during the middle Holocene. An increase in the precipitation–evaporation balance is indicated above unconformities dated to ∼230014C yr B.P. in both Lago Taypi Chaka Kkota and Laguna Viscachani. An abrupt increase in sediment accumulation rates after 140014C yr B.P. signals the onset of Neoglaciation. A possible link exists between the observed millennial-scale shifts in the regional precipitation–evaporation balance and seasonal shifts in tropical insolation.

High-resolution late Paleozoic cyclostratigraphy and tectonic evolution of the Keeler Basin, California, southwest Laurentia

2021 ◽  
Author(s):  
Patrick J. Gannon ◽  
M. Elliot Smith ◽  
Paul J. Umhoefer ◽  
Ryan J. Leary
Keyword(s):  
Gamma Ray ◽  
Sediment Accumulation ◽  
Foreland Basin ◽  
R Package ◽  
Accumulation Rates ◽  
Fine Grained ◽  
Upper Paleozoic ◽  
Optimization Function ◽  
Scale Optimization ◽  
Gamma Ray Log

Cyclic strata exposed in the Inyo Mountains of eastern California contain a continuous 6 m.y. record of deep marine deposition that spans the Pennsylvanian−Permian boundary. To better understand the geologic evolution of southwest Laurentia and the role of glacially driven eustasy in upper Paleozoic stratigraphy, we measured two detailed ∼600 m composite stratigraphic sections of the Keeler Canyon Formation and collected a handheld spectral gamma ray log. Post-depositional deformation complicates field relationships, but 1:5000 scale mapping of faults and folds permits assembly of two continuous sections. Measured strata alternate at the 5−20 m scale between intervals of fine-grained laminated marlstone and intervals of mixed carbonate and siliciclastic turbidites and debrites. Based on facies characteristics and a prominent marker horizon, we reassign the Pennsylvanian-Permian age upper Salt Tram unit of the upper Keeler Canyon Formation to a new Estelle Member. We estimate sediment accumulation rates within the Keeler Canyon Formation using published conodont biostratigraphy and correlative U-Pb geochronology from Eastern Europe combined with spectral analysis and timescale optimization using the Astrochron R package. Evolutive harmonic analysis of gamma ray-derived element concentrations reveals prominent bundled periodicities that are consistent with both long and short eccentricity cycles. Average sediment accumulation rates calculated using the time scale optimization function of Astrochron suggest a gradual increase from 40−60 m/m.y. to ∼120 m/m.y. during the late Pennsylvanian and then a minima of ∼50 m/m.y. near the Pennsylvanian−Permian boundary, which is followed by an increase to ∼175 m/m.y. into the Early Permian. This trend in sediment accumulation rates and subsequent Permian contractile deformation are compatible with flexural subsidence in a SW-migrating foreland basin related to the southern part of the late Antler orogenic system.

SEDIMENT ACCUMULATION RATES QUANTIFIED WITH COSMOGENIC NEON-21 ON A GLACIAL MORAINE, BLOODY CANYON, CA

2017 ◽  
Author(s):  
Daniel Morgan ◽  
◽  
Greg Balco ◽  
Alison Cribb ◽  
J. Warner Cribb ◽  
...  
Keyword(s):  
Sediment Accumulation ◽  
Accumulation Rates

Holocene climate change in the Bransfield Basin, Antarctic Peninsula: evidence from sediment and diatom analysis

2007 ◽  
Vol 20 (1) ◽  
pp. 69-87 ◽  
Author(s):  
David C. Heroy ◽  
Charlotte Sjunneskog ◽  
John B. Anderson
Keyword(s):  
Ocean Circulation ◽  
Sediment Accumulation ◽  
Sedimentary Facies ◽  
Ice Shelf ◽  
Diatom Analysis ◽  
Climate History ◽  
Radiocarbon Dates ◽  
Sedimentary Environments ◽  
Unstable Surface ◽  
Bransfield Basin

AbstractWe present the first study from the Bransfield Basin that extends through the Holocene, recording the variable climate history back to the decoupling of the ice sheet from the continental shelf ~10 650 calendar years before present (cal yr bp). Detailed sediment analysis reveals three stratigraphic units in PC-61 concomitant with three sedimentary environments, similar to sedimentary facies reported elsewhere: 1) subglacial, 2) glacial proximal/sub-ice shelf, and 3) open marine. These interpretations are based on a variety of sedimentological criteria, supported by ten AMS radiocarbon dates and detailed diatom analysis. We note two significant volcanic ash layers (tephra) at 3870 and 5500 cal yr bp from nearby Deception Island. Based on diatom assemblage analysis, we identify five separate climate regimes, highlighting a significantly shorter Mid-Holocene Climatic Optimum than reported by other studies (6800–5900 cal yr bp). This period is marked by the highest Eucampia antarctica var. antarctica and Fragilariopsis curta abundance, total diatom abundance, sediment accumulation rates, and low magnetic susceptibility. We also identify a less pronounced Neoglacial period relative to other studies, which includes an increase of Cocconeis/Rhizosolenia spp. assemblage related to unstable surface water conditions. Such observations probably reflect important regional variations in atmospheric or ocean circulation patterns.

The assessment of 210Pb data from sites with varying sediment accumulation rates

Hydrobiologia ◽  
1983 ◽  
Vol 103 (1) ◽  
pp. 29-35 ◽  
Author(s):  
P. G. Appleby ◽  
F. Oldfieldz
Keyword(s):  
Sediment Accumulation ◽  
Accumulation Rates

Linked variations in sediment accumulation rates and sea-level in Guanabara Bay, Brazil, over the last 6000years

2014 ◽  
Vol 415 ◽  
pp. 83-90 ◽  
Author(s):  
Alberto G. Figueiredo ◽  
Mauro B. de Toledo ◽  
Renato C. Cordeiro ◽  
José M.O. Godoy ◽  
Fabiano T. da Silva ◽  
...  
Keyword(s):  
Sea Level ◽  
Sediment Accumulation ◽  
Guanabara Bay ◽  
Accumulation Rates ◽  
And Sea Level

scholarly journals High-resolution magnetostratigraphy of the upper Nacimiento Formation, San Juan Basin, New Mexico, USA: implications for basin evolution and mammalian turnover

2017 ◽  
Author(s):  
Caitlin Leslie ◽  
Daniel J. Peppe ◽  
Thomas E. Williamson ◽  
Dario Bilardello ◽  
Matthew Heizler ◽  
...  
Keyword(s):  
New Mexico ◽  
North America ◽  
Accumulation Rate ◽  
Global Climate ◽  
Sediment Accumulation ◽  
San Juan ◽  
Accumulation Rates ◽  
Fluvial System ◽  
San Juan Basin ◽  
Geomagnetic Polarity

Lower Paleocene deposits in the San Juan Basin document one of the best records of mammalian change and turnover following the Cretaceous-Paleogene extinctions and are the type section for the Puercan (Pu) and Torrejonian (To) North America Land Mammal age biozones (NALMA). One of the largest mammalian turnover events in the early Paleocene occurs between the Torrejonian 2 (To2) and Torrejonian 3 (To3) NALMA biozones. The Nacimiento Formation are the only deposits in North America where the To2-To3 mammalian turnover can be constrained, however the precise age and duration of the turnover is poorly understood due to the lack of a precise chronostratigraphic framework. We analyzed paleomagnetic samples, produced a 40Ar/39Ar detrital sanidine age, and developed a detailed lithostratigraphy for four sections of the upper Nacimiento Formation in the San Juan Basin, New Mexico (Kutz Canyon, Escavada Wash, Torreon West and East) to constrain the age and duration of the deposits and the To2-To3 turnover. The polarity stratigraphy for the four sections can be correlated to chrons C27r-C26r of the geomagnetic polarity time scale (GPTS). Using the local polarity stratigraphy for each section, we calculated a mean sediment accumulation rate and developed a precise age model, which allows us to determine the age of important late Torrejonian mammalian localities. Using the assigned ages, we estimate the To2-To3 turnover was relatively rapid and occurred over ~120 kyr (-60/+50 kyr) between 62.59 and 62.47 Ma. This rapid duration of the mammalian turnover suggests that it was driven by external forcing factors, such as environmental change driven by the progradation of the distributive fluvial system across the basin and/or changes in regional or global climate. Additionally, comparisons of the mean sediment accumulation rates between the sections that span from the basin margin to the basin center indicate that sediment accumulation rates equalized across the basin from the end of C27r through the start of C26r, suggesting an accommodation minima in the basin associated with the progradation of a distributive fluvial system into the basin. This accommodation minimum also likely led to the long hiatus of deposition between the Paleocene Nacimiento Formation and the overlying Eocene San Jose Formation.

Sign in / Sign up

Export Citation Format

Share Document