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Stragraphic correlaon and signal propagaon across sedimentary system segments using
U-Pb detrital zircon geochronology: insights from the late Pleistocene Mississippi River and deep-sea fan
1Jourdan Speessen, 1Cody C. Mason, 1Jack Heltzer, 1G. Paul Miles II,
2Daniel F. Stockli, 3Brian W. Romans, and 4Andrea Fildani
1University of West Georgia, 2UT Ausn, 3Virginia Tech, 4Equinor Research Center, Ausn Texas
Maximum extent of
major glacial lakes
Maximum ice extent
during last glacial maximum
Maps and cross sections B-B’, C-C’
after Rittenour et al. (2007)
0 20 40 60 80 100
(fluvial) 25 ka
BSamples MV01 C'
Undifferentiated Ter tiary
15 ka Hmm3 Hb
40 60 80 120
SH MIS Depth
Bedrock crystallization ages
Relative proportions of
U-Pb DZ ages
DSDP Leg 96
Core Site 615
Hypothesis: disnct detrital zircon (DZ) age spectra from deep-sea fans can be correlated to ﬂuvial strata
Miss. Valley coastal
not to scale
01000 2000 3000 Ma
Do ﬂuvial deposits preserve DZ age
spectra idencal to those from correlave
DZ age spectra?
>29 ka <29 ka
schemac deep-sea core
and DZ age spectra
seismic horizon (H20)
The Mississippi River ﬂuvial network has undergone signiﬁcant modiﬁcaons during the Pleistocene that are aributed to ﬂuctuaons in northern hemisphere
ice sheets. Terrigenous sediments in the Mississippi deep-sea fan, Gulf of Mexico, preserve stragraphic changes in U-Pb detrital zircon (DZ) provenance that are
interpreted to result from up-system changes in sediment supply and source area, largely driven by ice sheet dynamics and the sedimentary system response.
Here, we build on exisng work focused on sediment composion, geochemistry, and DZ provenance of the Mississippi deep-sea fan, by measuring U-Pb ages of
DZs from deposits in upstream (and me correlave) ancient Mississippi River deposits, which would have fed submarine fans in the Gulf of Mexico.
We performed reconnaissance level sampling of full glacial to early deglacial age deposits in the Western Lowlands and central Mississippi Valley (deposional
ages of ~25 ka and ~15 ka, respecvely). We hypothesize that measured DZ age paerns from ancient river sediments in the Mississippi Valley should be similar
to those found in the upper most, me-correlave deep-sea fan deposits. If this hypothesis is veriﬁed by new DZ provenance results, it would demonstrate (1)
the ulity of relavely high resoluon stragraphic correlaon using DZ geochronology across source to sink system segments, and (2) further improve our
understanding of the eﬀects of ice sheets on funconing of connent-scale source to sink systems. Furthermore, this result would suggest rapid system response
mescales to external forcing, and rapid signal propagaon from source to sink. However, if ﬂuvial deposits contain DZ age paerns with signiﬁcant departures
from those of correlave deep-sea fan deposits, interpretaons of rapid signal propagaon or preservaon from source to sink, and inversion of stragraphic
records from the Mississippi deep-sea fan may need to be reevaluated. This phase of our study targets some of the youngest late Pleistocene deposits in the
Mississippi Valley and Mississippi fan, and future work will analyze older ﬂuvial deposits (ca. 70 – 40 ka) to further test the applicability of U-Pb DZ methods to
stragraphic correlaon across sedimentary system segments.
Scan the QR code to link to a downloadable
abstract in Research Gate
Deep-sea Sediment Provenance Mississippi Fluvial System
Figures (A, B, C) from Mason et al. in prep
Deep-sea fan data from Fildani et al. (2018)
MV01 25 ka
MV03 15 ka
Upper Mississippi River
Above H20 MIS-2
Below H20 MIS-3/4/5
MV01 N=3 (n=362/365)
MV03 N=3 (n = 377/377)
Ohio River N=3 (n = 286/286)
Missouri River N=2 (n = 192/193)
Upper Mississippi River N=1 (n = 95/96)
Lower Mississippi/delta N=3 (n = 590/597)
Above H20 N=4 (n = 404/405)
Below H20 N=3 (n = 424/426)
MV01 bulk sed (n=124/125)
MV03 bulk sed (n=126/126)
MV01 250-125 (n=109/110)
MV01 125-63 (n=129/130)
MV03 250-125 (n=121/121)
MV03 125-63 (n=130/130)
MV01 bulk sed
MV03 bulk sed
>500 μm 500-250 μm 250-125 μm 125-630 μm <63 μm
bulk weight % vs. grain size (μm)
METHODS AND RESULTS
U-Pb Detrital Zircon Geochronology From the Ancient and Modern Mississippi System
Methods: We used a power auger and a vibracore to recover sand-sized
sediment from previously dated (Rienour et al., 2007) Pleistocene
Mississippi River deposits overlain by >2-3 m of Peoria loess.
We sieved bulk sediment into medium, ﬁne, and very ﬁne size fracons.
We then applied laser ablaon–inducvely coupled plasma–mass
spectrometry U-Pb dang of zircon grains at the UTChron Lab.
We ploed DZ data using detritalPy (Sharman et al., 2018)
Images (le to right): troubleshoong a slightly broken
power auger in the mud, enjoying the sights of West Helena
(eastern Arkansas), the crew with our (ineﬀectual) vibracore,
and ﬁnally sampling success at site MV01.
1. MV01 (25 ka, W. Lowlands) has less Gondwanan/Appalachian DZs
than MV03 (15 ka, E. Lowlands).
2. MV01 has more Archean DZs, e.g. Trans-Hudson/Penokean and
Wyoming/Superior than MV03.
3. MV01 samples have a pronounced Jurassic (~160 Ma) age mode
compared to MV03.
4. DZs from diﬀerent grain size fracons are broadly similar, except in
MV01 250-125 (ﬁne sand). These results are inconclusive, but merit
5. DZs in our new 25 – 15 ka ﬂuvial samples are most similar to
“above H20” deep-sea fan DZ samples.
Figures (above and right): Cumulave distribuon funcons, kernel density
esmates and histograoms from U-Pb DZ samples used in this study. (above) Top to
boom: amalgamated late Pleistocene ﬂuvial samples, modern ﬂuvial to deltaic
samples from the Mississippi system (Blum and Pecha, 2014; Iizuka et al., 2010),
and deep-sea fan samples (Fildani et al., 2018).
(right): Bulk late Pleistocene ﬂuvial DZ samples, and those seived into 250 - 125 μm
(f sand), and 125 - 63 μm (very ﬁne sand).
CONCLUSIONS AND FUTURE WORK
U-Pb DZ Sample Similarity Mississippi River to fan Sediment Roung
We thank Equinor for funding a poron of this study.
Rienour, T.M., Blum, M.D., Goble, R.J., 2007. Fluvial evoluon of the lower Mississippi River valley during the last 100
k.y. glacial cycle: Response to glaciaon and sea-level change. Geol. Soc. Am. Bull. 119, 586–608.
Fildani, A., Hessler, A.M., Mason, C.C., Mckay, M.P., Stockli, D.F., 2018. Late Pleistocene glacial transions in North
America altered major river drainages , as revealed by deep-sea sediment. Sci. Rep. 1–8.
Sharman, G.R., Sharman, J.P., Sylvester, Z., 2018. detritalPy : A Python - based toolset for visualizing and analysing
detrital geo - thermochronologic data 202–215. doi:10.1002/dep2.45
Iizuka, T., Komiya, T., Rino, S., Maruyama, S., Hirata, T., 2010. Detrital zircon evidence for Hf isotopic evoluon of
granitoid crust and connental growth. Geochim. Cosmochim. Acta 74, 2450–2472. doi:10.1016/j.gca.2010.01.023
Vermeesch, P., 2013. Mul-sample comparison of detrital age distribuons. Chem. Geol. 341, 140–146.
Conclusions: Our new data suggest that ancestral Missouri-Mississippi River
sediments with deposional ages between 15 - 25 ka strongly inﬂuenced
the composion of me-correlave deep-sea fan deposits in the Gulf of
Mexico. The apparent high connecvity of system segments suggest rapid
signal propagaon across the sediment roung system.
A logical follow up queson is “what are the DZ age signitures of ﬂuvial
samples in the Mississippi Valley between ca. 40 -70 ka, and will they
resemble ‘below H20’ deep-sea fan DZ samples?”
Future Work: Sample ancient Mississippi River deposits correlave to the
lower-older fan (below H20; MIS-4, MIS-5a).
Figures (above): Muldimenonal scaling map for DZ samples from the Mississippi system.
For explanaon of axes, see Vermeesch, (2013), produced using detritalPy (Sharman et al.,
2018). (right): Mississippi River Valley with Late Pleistocene river channel locaons, and
pies showing propoons of U-Pb DZ ages present in samples.
DZ age spectra of the modern Missouri River are highly similar to samples
from both the Western and Eastern Lowlands, between 25 - 15 ka,
respecvely. Similarity of deep-sea fan samples (above H20; <29 ka) and
me correlave ﬂuvial samples MV01, MV03, suggests the fan was heavily
inﬂuenced by the composion of up-system ﬂuvial sediment, and most
likely by the DZ composion of the ancient Missouri River.
Modern Ohio River
Modern Missouri River Modern Upper
MV03 bulk sed
Modern Lower Mississippi
MIS-2 Mississippi fan
deep-sea fan transfer
Below H20 Upper
MV03 125-63 MV01 125-63
Western Cordilla (280-0 Ma)
Gondwana/Appalachian (280-800 Ma)
Grenville (900-1300 Ma)
Yavapai/Mazatzal (1600-1800 Ma)
Granite/Rhyolite (1500-1300 Ma)
Trans-Hudson/Penokean (1800-2000 Ma)
Wyoming/Superior (>2500 Ma)
Mississippi fan (above H20)
most similar to 25 - 15 ka
fluvial samples, modern
Missouri fluvial samples
Mississippi fan (below H20)
most similar to modern
Upper Mississippi, Missouri,
and Ohio fluvial samples