scholarly journals IODP Expedition 324: Ocean Drilling at Shatsky Rise Gives Clues about Oceanic Plateau Formation

2011 ◽  
Vol 12 ◽  
pp. 24-31 ◽  
Author(s):  
W. W. Sager ◽  
T. Sano ◽  
J. Geldmacher ◽  
Keyword(s):  
Ocean Drilling Program ◽  
Ontong Java Plateau ◽  
Shatsky Rise ◽  
Oceanic Plateau ◽  
Ocean Drilling ◽  
Integrated Ocean Drilling Program ◽  
High Fluid ◽  
Formation And Evolution ◽  
Effusion Rates ◽  
Tamu Massif

Integrated Ocean Drilling Program (IODP) Expedition 324 cored Shatsky Rise at five sites (U1346–U1350) to study processes of oceanic plateau formation and evolution. Site penetrations ranged from 191.8 m to 324.1 m with coring of 52.6 m to 172.7 m into igneous basement at four of the sites. Average recovery in basement was 38.7%–67.4%. Cored igneous sections consist mainly of variably evolved tholeiitic basalts emplaced as pillows or massive flows. Massive flows are thickest and make up the largest percentage of section on the largest and oldest volcano, late Jurassic age Tamu Massif; thus, it may have formed at high effusion rates. Such massive flows are characteristic of flood basalts, and similar flows were cored at Ontong Java Plateau. Indeed, the similarity of igneous sections at Site U1347 with that cored on Ontong Java Plateau implies similar volcanic styles for these two plateaus. On younger, smaller Shatsky Rise volcanoes, pillow flows are common and massive flows thinner and fewer, which might mean volcanism waned with time. Cored sediments from summit sites contain fossils and structures implying shallow water depths or emergence at the time of eruption and normal subsidence since. Summit sites also show pervasive alteration that could be due to high fluid fluxes. A thick section of volcaniclastics cored on Tamu Massif suggests that shallow, explosive submarine volcanism played a significant role in the geologic development of the plateau summit. Expedition 324 results imply that Shatsky Rise began with massive eruptions forming a huge volcano and that subsequent eruptions waned in intensity, forming volcanoes that are large, but which did not erupt with unusually high effusion rates. Similarities of cored sections on Tamu Massif with those of Ontong Java Plateau indicate that these oceanic plateaus formed in similar fashion. <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.12.03.2011" target="_blank">10.2204/iodp.sd.12.03.2011</a>

scholarly journals IODP Expedition 318: From Greenhouse to Icehouse at the Wilkes Land Antarctic Margin

2011 ◽  
Vol 12 ◽  
pp. 15-23 ◽  
Author(s):  
C. Escutia ◽  
H. Brinkhuis ◽  
A. Klaus ◽  
Keyword(s):  
Middle Eocene ◽  
Second Phase ◽  
Last Deglaciation ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
Integrated Ocean Drilling Program ◽  
Tectonic History ◽  
Wilkes Land ◽  
History Of

Integrated Ocean Drilling Program (IODP) Expedition 318, Wilkes Land Glacial History, drilled a transect of sites across the Wilkes Land margin of Antarctica to provide a long-term record of the sedimentary archives of Cenozoic Antarctic glaciation and its intimate relationships with global climatic and oceanographic change. The Wilkes Land drilling program was undertaken to constrain the age, nature, and paleoenvironment of the previously only seismically inferred glacial sequences. The expedition (January–March 2010) recovered ~2000 meters of high-quality middle Eocene–Holocene sediments from water depths between 400 m and 4000 m at four sites on the Wilkes Land rise (U1355, U1356, U1359, and U1361) and three sites on the Wilkes Land shelf (U1357, U1358, and U1360). <br><br> These records span ~53 million years of Antarctic history, and the various seismic units (WL-S4–WL-S9) have been successfully dated. The cores reveal the history of the Wilkes Land Antarctic margin from an ice-free “greenhouse” Antarctica, to the first cooling, to the onset and erosional consequences of the first glaciation and the subsequent dynamics of the waxing and waning ice sheets, all the way to thick, unprecedented "tree ring style" records with seasonal resolution of the last deglaciation that began ~10,000 y ago. The cores also reveal details of the tectonic history of the Australo-Antarctic Gulf from 53 Ma, portraying the onset of the second phase of rifting between Australia and Antarctica, to ever-subsiding margins and deepening, to the present continental and ever-widening ocean/continent configuration. <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.12.02.2011" target="_blank">10.2204/iodp.sd.12.02.2011</a>

scholarly journals IODP Expedition 335: Deep Sampling in ODP Hole 1256D

2012 ◽  
Vol 13 ◽  
pp. 28-34 ◽  
Author(s):  
D. A. H. Teagle ◽  
B. Ildefonse ◽  
P. Blum ◽  
Keyword(s):  
Theoretical Models ◽  
Spreading Rate ◽  
Ocean Crust ◽  
Ocean Drilling Program ◽  
Drill Cuttings ◽  
Ocean Drilling ◽  
Ocean Ridges ◽  
Integrated Ocean Drilling Program ◽  
Geological Conditions ◽  
Ocean Lithosphere

Observations of the gabbroic layers of untectonized ocean crust are essential to test theoretical models of the accretion of new crust at mid-ocean ridges. Integrated Ocean Drilling Program (IODP) Expedition 335 ("Superfast Spreading Rate Crust 4") returned to Ocean Drilling Program (ODP) Hole 1256D with the intention of deepening this reference penetration of intact ocean crust a significant distance (~350 m) into cumulate gabbros. Three earlier cruises to Hole 1256D (ODP 206, IODP 309/312) have drilled through the sediments, lavas, and dikes and 100 m into a complex dike-gabbro transition zone. <br><br> Operations on IODP Expedition 335 proved challenging throughout, with almost three weeks spent re-opening and securing unstable sections of the hole. When coring commenced, the comprehensive destruction of the coring bit required further remedial operations to remove junk and huge volumes of accumulated drill cuttings. Hole-cleaning operations using junk baskets were successful, and they recovered large irregular samples that document a hitherto unseen sequence of evolving geological conditions and the intimate coupling between temporally and spatially intercalated intrusive, hydrothermal, contact-metamorphic, partial melting, and retrogressive processes. <br><br> Hole 1256D is now clean of junk, and it has been thoroughly cleared of the drill cuttings that hampered operations during this and previous expeditions. At the end of Expedition 335, we briefly resumed coring before undertaking cementing operations to secure problematic intervals. To ensure the greatest scientific return from the huge efforts to stabilize this primary ocean lithosphere reference site, it would be prudent to resume the deepening of Hole 1256D in the nearest possible future while it is open to full depth. <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.13.04.2011" target="_blank">10.2204/iodp.sd.13.04.2011</a>

Late Neogene–Quaternary Planktic Foraminiferal Biostratigraphy and Biochronology from ODP Site 807A, Ontong Java Plateau, Western Equatorial Pacific

2020 ◽  
Vol 50 (2) ◽  
pp. 111-127
Author(s):  
Tushar Kaushik ◽  
Ashutosh Kumar Singh ◽  
Devesh Kumar Sinha
Keyword(s):  
Equatorial Pacific ◽  
Ocean Drilling Program ◽  
Ontong Java Plateau ◽  
Faunal Turnover ◽  
Ocean Drilling ◽  
Late Neogene ◽  
Western Equatorial Pacific ◽  
Globorotalia Truncatulinoides ◽  
Oceanographic Conditions ◽  
Foraminiferal Biostratigraphy

ABSTRACT A biostratigraphic and biochronological study from the late Neogene–Quaternary section of Ocean Drilling Program (ODP) Site 807A, located on the Ontong Java Plateau, western equatorial Pacific, revealed 50 planktic foraminiferal events, enabling the identification of eight late Neogene–Quaternary biozones, from the Globorotalia plesiotumida Interval Zone to the Globorotalia truncatulinoides Interval Zone. A significant faunal turnover (17 events) from late Pliocene identified in cores 7 and 8, between 70 and 55 meters below seafloor (mbsf), and spanning 0.67 million years (Myr). This noteworthy turnover may be the result of a shift in oceanographic conditions pertaining to the closure of the Indo–Pacific Seaway, followed by the Northern Hemisphere Glaciation. This study provides a high resolution biostratigraphic and biochronological framework for ODP Site 807A that will aid in correlation and timing the various paleoceanographic changes over the last 6 million years in the western equatorial Pacific.

High resolution CO2 record of the great Plio-Pleistocene glaciations using boron isotopes

2020 ◽  
Author(s):  
Rachel Brown ◽  
Thomas Chalk ◽  
Paul Wilson ◽  
Eelco Rohling ◽  
Gavin Foster
Keyword(s):  
High Resolution ◽  
Northern Hemisphere ◽  
Large Scale ◽  
Boron Isotope ◽  
Ocean Drilling Program ◽  
Proxy Record ◽  
Ocean Drilling ◽  
Integrated Ocean Drilling Program ◽  
Great Transition ◽  
Adequate Test

&lt;p&gt;The intensification of Northern Hemisphere glaciation (iNHG) at 3.4-2.5 million years ago (Ma) represents the last great transition in Cenozoic climate state with the development of large scale ice sheets in the Northern Hemisphere that waxed and waned with changes in insolation. Declining atmospheric CO&lt;sub&gt;2&lt;/sub&gt; levels are widely suggested to have been the main cause of iNHG but the CO&lt;sub&gt;2&lt;/sub&gt; proxy record is too poorly resolved to provide an adequate test of this hypothesis. The boron isotope-pH proxy, in particular, has shown promise when it comes to accurately estimating past CO&lt;sub&gt;2&lt;/sub&gt; concentrations and is very good at reconstructing relative changes in CO&lt;sub&gt;2&lt;/sub&gt; on orbital timescales. Here we present a new orbitally resolved record of atmospheric CO&lt;sub&gt;2 &lt;/sub&gt;(1 sample per 3 kyr) change from Integrated Ocean Drilling Program Site 999 (12.74&amp;#730;N, -78.74 &amp;#730;E) spanning ~2.6&amp;#8211;2.4&amp;#160;Ma based on the boron isotope (&amp;#948;&lt;sup&gt;11&lt;/sup&gt;B) composition of planktic foraminiferal calcite, &lt;em&gt;Globingerinoides ruber&lt;/em&gt; (senso stricto, white). &amp;#160;We find that &amp;#948;&lt;sup&gt;11&lt;/sup&gt;B values of &lt;em&gt;G. ruber&lt;/em&gt; show clear glacial-interglacial cycles with a magnitude that is similar to those of the Mid-Pleistocene at the same site and elsewhere.&amp;#160; This new high-resolution view of CO&lt;sub&gt;2&lt;/sub&gt; during the first large glacial events of the Pleistocene confirms the importance of CO&lt;sub&gt;2&lt;/sub&gt; in amplifying orbital forcing of climate and offers new insights into the mechanistic drivers of natural CO&lt;sub&gt;2&lt;/sub&gt; change.&amp;#160;&lt;/p&gt;

scholarly journals Fresh-water and salt-water distribution in passive margin sediments: Insights from Integrated Ocean Drilling Program Expedition 313 on the New Jersey Margin

Geosphere ◽  
2013 ◽  
Vol 9 (4) ◽  
pp. 1009-1024 ◽  
Author(s):  
Johanna Lofi ◽  
Jennifer Inwood ◽  
Jean-Noël Proust ◽  
Donald H. Monteverde ◽  
Didier Loggia ◽  
...  
Keyword(s):  
New Jersey ◽  
Fresh Water ◽  
Water Distribution ◽  
Salt Water ◽  
Passive Margin ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
Integrated Ocean Drilling Program
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