Analysis and Correlation of Volcanic Ash in Marine Sediments from the Peru Margin, Ocean Drilling Program Leg 201: Explosive Volcanic Cycles of the North-Central Andes

2006 ◽  
Author(s):  
D. Hart ◽  
D.J. Miller
Keyword(s):  
Marine Sediments ◽  
Volcanic Ash ◽  
Central Andes ◽  
Ocean Drilling Program ◽  
North Central ◽  
Ocean Drilling ◽  
The North ◽  
Volcanic Cycles

scholarly journals Maastrichtian–Rupelian paleoclimates in the southwest Pacific – a critical re-evaluation of biomarker paleothermometry and dinoflagellate cyst paleoecology at Ocean Drilling Program Site 1172

2021 ◽  
Vol 17 (6) ◽  
pp. 2393-2425
Author(s):  
Peter K. Bijl ◽  
Joost Frieling ◽  
Margot J. Cramwinckel ◽  
Christine Boschman ◽  
Appy Sluijs ◽  
...  
Keyword(s):  
Marine Sediments ◽  
State Of The Art ◽  
Middle Eocene ◽  
Potential Temperature ◽  
Critical Evaluation ◽  
Marine Biodiversity ◽  
Early Eocene ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
Sw Pacific

Abstract. Sea surface temperature (SST) reconstructions based on isoprenoid glycerol dialkyl glycerol tetraether (isoGDGT) distributions from the Eocene southwest (SW) Pacific Ocean are unequivocally warmer than can be reconciled with state-of-the-art fully coupled climate models. However, the SST signal preserved in sedimentary archives can be affected by contributions of additional isoGDGT sources. Methods now exist to identify and possibly correct for overprinting effects on the isoGDGT distribution in marine sediments. Here, we use the current proxy insights to (re-)assess the reliability of the isoGDGT-based SST signal in 69 newly analyzed and 242 reanalyzed sediments at Ocean Drilling Program (ODP) Site 1172 (East Tasman Plateau, Australia) following state-of-the-art chromatographic techniques. We compare our results with paleoenvironmental and paleoclimatologic reconstructions based on dinoflagellate cysts. The resulting ∼ 130 kyr resolution Maastrichtian–Oligocene SST record based on the TetraEther indeX of tetraethers with 86 carbon atoms (TEX86) confirms previous conclusions of anomalous warmth in the early Eocene SW Pacific and remarkably cool conditions during the mid-Paleocene. Dinocyst diversity and assemblages show a strong response to the local SST evolution, supporting the robustness of the TEX86 record. Soil-derived branched GDGTs stored in the same sediments are used to reconstruct mean annual air temperature (MAAT) of the nearby land using the Methylation index of Branched Tetraethers with 5-methyl bonds (MBT'5me) proxy. MAAT is consistently lower than SST during the early Eocene, independent of the calibration chosen. General trends in SST and MAAT are similar, except for (1) an enigmatic absence of MAAT rise during the Paleocene–Eocene Thermal Maximum and Middle Eocene Climatic Optimum, and (2) a subdued middle–late Eocene MAAT cooling relative to SST. Both dinocysts and GDGT signals suggest a mid-shelf depositional environment with strong river runoff during the Paleocene–early Eocene progressively becoming more marine thereafter. This trend reflects gradual subsidence and more pronounced wet/dry seasons in the northward-drifting Australian hinterland, which may also explain the subdued middle Eocene MAAT cooling relative to that of SST. The overall correlation between dinocyst assemblages, marine biodiversity and SST changes suggests that temperature exerted a strong influence on the surface-water ecosystem. Finally, we find support for a potential temperature control on compositional changes of branched glycerol monoalkyl glycerol tetraethers (brGMGTs) in marine sediments. It is encouraging that a critical evaluation of the GDGT signals confirms that most of the generated data are reliable. However, this also implies that the high TEX86-based SSTs for the Eocene SW Pacific and the systematic offset between absolute TEX86-based SST and MBT'5me-based MAAT estimates remain without definitive explanation.

A late Quaternary bio- and climatostratigraphy for marine sediments in the north-central part of the North Sea

Boreas ◽  
2008 ◽  
Vol 7 (2) ◽  
pp. 91-96 ◽  
Author(s):  
REX HARLAND ◽  
DIANE M. GREGORY ◽  
MURRAY J. HUGHES ◽  
IAN P. WILKINSON
Keyword(s):  
North Sea ◽  
Marine Sediments ◽  
Late Quaternary ◽  
North Central ◽  
The North ◽  
The North Sea

scholarly journals Integrated uppermost Campanian–Maastrichtian calcareous nannofossil and foraminiferal biostratigraphic zonation of the northwestern margin of Australia

2003 ◽  
Vol 22 (1) ◽  
pp. 29-62 ◽  
Author(s):  
R. W. Howe ◽  
R. J. Campbell ◽  
J. P. Rexilius
Keyword(s):  
Planktonic Foraminifera ◽  
Petroleum Exploration ◽  
Calcareous Nannofossil ◽  
Ocean Drilling Program ◽  
Exmouth Plateau ◽  
Ocean Drilling ◽  
The North ◽  
Northwestern Margin ◽  
Upper Maastrichtian ◽  
Upper Campanian

Abstract. During the latest Campanian–Maastrichtian the northwestern Australian margin was situated between the cool-water Austral Province to the south and the warm-water Tethyan Province to the north. The transitional nature of calcareous microfossil assemblages on the margin makes application of Tethyan biostratigraphic zonation schemes awkward, as many marker-species are missing or have different ranges. This study presents an integrated uppermost Campanian–Maastrichtian calcareous microfossil zonation based on two Ocean Drilling Program (ODP) holes on the Exmouth Plateau and eight petroleum exploration wells from the Vulcan Sub-basin. The zonation is refined and revised from the previously unpublished KCN (nannofossils), KPF (planktonic foraminifera), KBF (benthonic foraminifera) and KCCM (composite nannofossil and planktonic foraminifera) zonations, which are commonly used for petroleum exploration wells drilled on the northwestern margin. Revision of the zonations has highlighted a major Upper Campanian to lower Upper Maastrichtian disconformity on the Exmouth Plateau, which went largely unnoticed in previous examinations of the ODP material, but had been recorded previously elsewhere on the northwestern margin. The duration of the disconformity in the Vulcan Sub-basin is unclear, since intervals of the succession may be condensed in this area.

U-Pb geochronologic evidence for the evolution of the Gondwanan margin of the north-central Andes

2007 ◽  
Vol 119 (5-6) ◽  
pp. 697-711 ◽  
Author(s):  
D. M. Chew ◽  
U. Schaltegger ◽  
J. Kosler ◽  
M. J. Whitehouse ◽  
M. Gutjahr ◽  
...  
Keyword(s):  
Central Andes ◽  
North Central ◽  
The North

scholarly journals VOLCORE, a global database of visible tephra layers sampled by ocean drilling

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Sue H. Mahony ◽  
Nicholas H. Barnard ◽  
R. Stephen J. Sparks ◽  
Jonathan C. Rougier
Keyword(s):  
Volcanic Ash ◽  
Ocean Drilling Program ◽  
Sea Floor ◽  
Global Database ◽  
Ocean Drilling ◽  
Integrated Ocean Drilling Program ◽  
Starting Point ◽  
Tephra Layers ◽  
Global Coverage ◽  
International Ocean Discovery Program

Abstract The VOLCORE (Volcanic Core Records) database is a collection of 34,696 visible tephra (volcanic ash and lithological or grain size variations) occurrences reported in the initial reports volumes of all of the Deep Sea Drilling Project (DSDP; 1966–1983), the Ocean Drilling Program (ODP; 1983–2003), the Integrated Ocean Drilling Program (IODP; 2003–2013) and the International Ocean Discovery Program (IODP; 2013-present) up to and including IODP Expedition 381. The combined international ocean drilling programmes (OD) have locations with global coverage. Cored tephra layers and tephra-bearing sediments span timescales from recent to ~150 million years in age. This database is a collection of information about reported visible tephra layers entirely or predominantly composed of volcanic ash. Data include the depth below sea floor, tephra thickness, location, and any reported comments. An approximate age was estimated for most (29,493) of the tephra layers using published age-depth models. The database can be used as a starting point for studies of tephrochronology, volcanology, geochemistry, studies of sediment transport and palaeoclimatology.

scholarly journals Is there a Central Andean Linguistic Area? A View from the Perspective of the “Minor” Languages

2019 ◽  
Vol 12 (2) ◽  
pp. 271-304 ◽  
Author(s):  
Matthias Urban
Keyword(s):  
Central Andes ◽  
The Other ◽  
North Central ◽  
Clear Cut ◽  
The North ◽  
High Degree

In this article, I reconsider the evidence for a Central Andean linguistic area. I suggest that there is no evidence for a clear-cut linguistic area comprising the entire Central Andes narrowly defined, and that perceived homogeneity is partially due to an overemphasis on the largest and surviving Central Andean language families, Quechuan and Aymaran. I show that none of the other Central Andean languages known sufficiently well match their typological profile to a high degree. I make a contribution to a more adequate picture by discussing some typological aspects tentatively recoverable for the extinct and poorly documented languages of the North-Central Andes. These suggest that the North was the site of linguistic traits contrasting with those of Quechuan and Aymaran.

scholarly journals Cenozoic Biostratigraphy and Global Change

1991 ◽  
Vol 9 (2) ◽  
pp. 117-117
Author(s):  
Brian M. Funnell
Keyword(s):  
Global Change ◽  
North Atlantic ◽  
Ocean Drilling Program ◽  
East Anglia ◽  
Ongoing Research ◽  
Ocean Drilling ◽  
The North ◽  
History Of ◽  
The North Atlantic ◽  
The University

Abstract. INTRODUCTIONIn May 1989 a British Micropalaeontological Society Symposium Meeting was held at the University of East Anglia under the title “Cenozoic Biostratigraphy and Global Change”. Fourteen lectures were given on this theme, many of them originating from investigations of DSDP/IPOD and ODP (Ocean Drilling Program) samples. All addressed the potential of micropalaeontological observations for interpreting the history of global and regional oceanographic and climatic change. Many results of this type of investigation are currently appearing in science journals such as “Paleoceanography” and “Palaeogeography, Palaeoclimatology, Palaeoecology” as well as in the “Proceedings of the Ocean Drilling Program”. British micropalaeontologists are taking an active part in this research, but relatively few of the resultant papers have so far appeared in the Journal of Micropalaeontology.Many of the lectures given at the May 1989 Symposium represented work already recently published, or due to be subsequently published in the Proceedings of the Ocean Drilling Program. Four papers, representing ongoing research not then due to be published, have been brought together here as a small thematic set, illustrating a variety of approaches to “Cenozoic Biostratigraphy and Global Change”. They range across Ostracoda, Coccolithophorida, Planktonic and Benthic Foraminifera, through the entire Cenozoic, including the latest Quaternary, and they include results from both the North Atlantic and Pacific oceans.TITLES“Global Change and the Biostratigraphy of North Atlantic Cenozoic deep water Ostracoda” - Robin C. Whatley and Graham P. Coles.“Palaeoclimatic control of Upper Pliocene Discoaster assemblages in the North Atlantic” - Alex. Chepstow-Lusty, Jan Backman. . .

scholarly journals Regional and global signals in seawater δ18O records across the mid-Pleistocene transition

Geology ◽  
2019 ◽  
Vol 48 (2) ◽  
pp. 113-117 ◽  
Author(s):  
Heather L. Ford ◽  
Maureen E. Raymo
Keyword(s):  
Ocean Circulation ◽  
North Pacific Ocean ◽  
Deep Ocean ◽  
Ocean Drilling Program ◽  
Ocean Drilling ◽  
Ice Volume ◽  
The North ◽  
Global Ice Volume ◽  
Deep Ocean Water ◽  
Deep Ocean Circulation

Abstract High-resolution seawater δ18O records, derived from coupled Mg/Ca and benthic δ18O analyses, can be used to evaluate how global ice volume changed during the mid-Pleistocene transition (MPT, ca. 1250–600 ka). However, such seawater δ18O records are also influenced by regional hydrographic signals (i.e., salinity) and changes in deep-ocean circulation across the MPT, making it difficult to isolate the timing and magnitude of the global ice volume change. To explore regional and global patterns in seawater δ18O records, we reconstruct seawater δ18O from coupled Mg/Ca and δ18O analyses of Uvigerina spp. at Ocean Drilling Program Site 1208 in the North Pacific Ocean. Comparison of individual seawater δ18O records suggests that deep-ocean circulation reorganized and the formation properties (i.e., salinity) of deep-ocean water masses changed at ca. 900 ka, likely related to the transition to marine-based ice sheets in Antarctica. We also find that an increase in ice volume likely accompanied the shift in glacial-interglacial periodicity observed in benthic carbonate δ18O across the MPT, with increases in ice volume observed during Marine Isotope Stages 22 and 16.

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