DOCSLIB.ORG

Cenozoic Eridanos Delta Hydrocarbon System

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Cenozoic Eridanos Delta Hydrocarbon System GAS TECHNOLOGY CENOZOIC ERIDANOS DELTA HYDROCARBON SYSTEM Shallow (<1 km) gas accumulations SHALLOW GAS – wHAT DO WE KNOW Seismic amplitude data of the Eridanos delta, on the Dutch shelf were recognized Shallow gas occurs in unconsolidated, showing reflection anomalies (‘bright spots’) indicative of shallow gas accumulations. in the 1970s but were never Cenozoic sediments on the Dutch continen- tal shelf, particularly in shallow marine to developed because of low reservoir continental (deltaic) deposits of the pressures and unconsolidated Plio-Pleistocene Eridanos delta. The sand issues. Current interest in shallow marine to continental deposits these accumulations comes forth accumulated both from deep thermogenic from a stronger demand on the gas sources and from biogenic sources in market and the availability of newer shallower strata. They are either structur- ally trapped in anticlines associated with production techniques. Therefore, rising salt domes or occur in stratigraphic many operators re-explore the or depositional traps. The gas accumula- potential of the North Sea’s shallow tions may be economically attractive, gas. Currently five such operators especially if located near existing infra- are pooling data in a TNO joint structures. The Dutch thermogenic, industry sponsor project. biogenic and mixed shallow gas systems are highly dynamic. Gas chimneys, acoustic turbidity and blanking, pockmarks and stacked bright spots, as well as methane dissolved in groundwater, all indicate ongoing and/or recent migration and leakage of shallow gas. Shallow gas GAS TECHNOLOGY Locality of the Tertiary- Pleistocene Eridanos river (yellow) and delta (orange) system. production in the Dutch offshore is still This will be achieved by constructing a 3D, limited by a lack of familiarity with the basin-scale reservoir model of the shallow shallow gas systems, especially with gas systems contained in the Cenozoic respect to the unclear relationship between Eridanos delta. Key external controls will anatomy of the delta and charging/ be linked directly to depositional elements trapping conditions at specific stratigraphic (fans, valley fills, clinoforms and topsets) intervals. calibrated by extensive well data, providing bio- and chronostratigraphic, geochemical KEY QUESTIONS and paleoenvironmental information. The Direct hydrocarbon indicators for shallow established reservoir model—in combina- gas occurrences include bright spots and tion with reconstruction of the areas of several other types of velocity anomalies, origin of biogenic and thermogenic gases which are well known by offshore operators and the charging, preservation and as they may strongly affect the correct pressure conditions in these reservoirs— imaging of deeper subsurface (energy forms the basis for improved prediction of absorption, ray distortion, etc). Their study other potential shallow gas occurrences and characterization have important offshore the Netherlands, either economic industry applications, both in geohazard profitable or hazardous. identification and in exploration of deeper levels. E&P would clearly benefit from an TNO increased understanding of how the TNO is one of Europe’s largest independent distribution of these environments is companies in the areas of technology related to external (climate, tectonics, development and technical consultancy. sea-level) and internal (delta-lobe switch- TNO employs over 4,000 scientists in a TNO.NL ing, avulsion) processes. A sequence-strati- wide range of economical sectors, graphic framework should provide critical including energy, mobility, industrial information about the architecture and innovation, information society and reservoir properties of these not yet defence. We have over 70 years of well-understood reservoirs and the experience in: continuity of sealing clays. − Advisory, independent from commercial interests OBJECTIVES − Development of innovative technologies The main objective of the study is to in close collaboration with major develop a workflow that assesses the industrial parties and universities. potential of seismic bright spots as − Knowledge transfer programs for indicators for shallow gas occurrences. industry and universities worldwide. We distinguish ourselves by our independ- TNO Mapped bright spots ent position and capability to address Dr. Johan ten Veen Legend Bright spots challenging technological issues with Princetonlaan 6 Shallow gas field Extend of mapped area multi-disciplinary teams of highly qualified 3584 TA UTRECHT scientists. We develop technology, on the basis of top quality scientific knowledge, T +31 88 866 45 32 into practical applications with industrial M +31 6 12 89 54 27 use. As an independent company TNO is E [email protected] not active in the production or commerciali- zation of its innovations. TNO.NL/energy.
Load more

Recommended publications
  • Provenance of Early Pleistocene Sediments Based on a High-Resolution Sedimentological Dataset of Borehole Petten, Southern North Sea
    Provenance of Early Pleistocene sediments based on a high-resolution sedimentological dataset of borehole Petten, southern North Sea Hao Ding 6559972 A thesis submitted for the degree of MSc Earth, Life and Climate Utrecht University July, 2020 1 Preface and Acknowledgements This thesis was written as part of the Master of Science degree in Earth Sciences, program Earth, Life and Climate, at Utrecht University. The research was performed under the supervision of Kim Cohen and Wim Hoek, also with help of Timme Donders and Alexander Houben. This research, together with a parallel research conducted by Lissane Krom, contributes to a larger project in paleoenvironment reconstruction of the Early Pleistocene in the southern North Sea Basin, based on the Petten Borehole 1. This thesis focused on sedimentology, and the parallel thesis by Krom focused on palynology. For the process of this project, I would like to express my gratitude to my supervisors Kim Cohen and Wim Hoek for their great effort on the research and lab work guidance. All the redactional and scientific comments on my writing from Kim Cohen are highly appreciated. I would also like to thank Timme Donders, Alexander Houben and Lisanne Krom for all the cross-disciplinary discussions as well as the assistance on my final presentation. Last but not least, I would like to thank my family and friends, who have been supporting me as always during this Covid-19 pandemic. Studying abroad has been tough, but I really appreciate all the love and encouragement around me, no matter how far apart we are. 2 Abstract In 2018, a fairly complete core (Petten BH 1) reaching over 300 meters into the unconsolidated, dominantly sandy Pleistocene sequence was recovered in the northwest of the Netherlands, in the coastal dune area along the present North Sea.
    [Show full text]
  • Pliocene Dinoflagellate Cyst Stratigraphy, Palaeoecology And
    Geol. Mag.: page 1 of 21. c 2008 Cambridge University Press 1 doi:10.1017/S0016756808005438 Pliocene dinoflagellate cyst stratigraphy, palaeoecology and sequence stratigraphy of the Tunnel-Canal Dock, Belgium STIJN DE SCHEPPER∗,MARTINJ.HEAD† & STEPHEN LOUWYE‡ ∗Cambridge Quaternary, Department of Geography, University of Cambridge, Downing Place, Cambridge CB2 3EN, UK †Department of Earth Sciences, Brock University, 500 Glenridge Avenue, St. Catharines, Ontario L2S 3A1, Canada ‡Palaeontology Research Unit, Ghent University, Krijgslaan 281 – S8, B-9000 Gent, Belgium (Received 21 November 2007; accepted 8 April 2008) Abstract – Dinoflagellate cysts and sequence stratigraphy are used to date accurately the Tunnel-Canal Dock section, which contains the most complete record of marine Pliocene deposits in the Antwerp harbour area. The Zanclean Kattendijk Formation was deposited between 5.0 and 4.4 Ma during warm- temperate conditions on a shelf influenced by open-marine waters. The overlying Lillo Formation is divided into four members. The lowest is the Luchtbal Sands Member, estimated to have been deposited between 3.71 and 3.21 Ma, under cooler conditions but with an open-water influence. The Oorderen Sands, Kruisschans Sands and Merksem Sands members of the Lillo Formation are considered a single depositional sequence, and biostratigraphically dated between 3.71 and c. 2.6 Ma, with the Oorderen Sands Member no younger than 2.72–2.74 Ma. Warm-temperate conditions had returned, but a cooling event is noted within the Oorderen Sands Member. Shoaling of the depositional environment is also evidenced, with the transgressive Oorderen Sands Member passing upwards into (near-)coastal high- stand deposits of the Kruisschans Sands and Merksem Sands members, as accommodation space decreased.
    [Show full text]
  • Geology of the Dutch Coast
    Geology of the Dutch coast The effect of lithological variation on coastal morphodynamics Deltores Title Geology of the Dutch coast Client Project Reference Pages Rijkswaterstaat Water, 1220040-007 1220040-007-ZKS-0003 43 Verkeer en Leefomgeving Keywords Geology, erodibility, long-term evolution, coastal zone Abstract This report provides an overview of the build-up of the subsurface along the Dutch shorelines. The overview can be used to identify areas where the morphological evolution is partly controlled by the presence of erosion-resistant deposits. The report shows that the build-up is heterogeneous and contains several erosion-resistant deposits that could influence both the short- and long-term evolution of these coastal zones and especially tidal channels. The nature of these resistant deposits is very variable, reflecting the diverse geological development of The Netherlands over the last 65 million years. In the southwestern part of The Netherlands they are mostly Tertiary deposits and Holocene peat-clay sequences that are relatively resistant to erosion. Also in South- and North-Holland Holocene peat-clay sequences have been preserved, but in the Rhine-Meuse river-mouth area Late Pleistocene• early Holocene floodplain deposits form additional resistant layers. In northern North-Holland shallow occurrences of clayey Eemian-Weichselian deposits influence coastal evolution. In the northern part of The Netherlands it are mostly Holocene peat-clay sequences, glacial till and over consolidated sand and clay layers that form the resistant deposits. The areas with resistant deposits at relevant depths and position have been outlined in a map. The report also zooms in on a few tidal inlets to quick scan the potential role of the subsurface in their evolution.
    [Show full text]
  • Ordovician Sponges (Porifera) and Other Silicifications from Baltica in Neogene and Pleistocene Fluvial Deposits of the Netherlands and Northern Germany
    Estonian Journal of Earth Sciences, 2009, 58, 1, 24–37 doi:10.3176/earth.2009.1.03 Ordovician sponges (Porifera) and other silicifications from Baltica in Neogene and Pleistocene fluvial deposits of the Netherlands and northern Germany Freek Rhebergen Slenerbrink 178, NL-7812 HJ Emmen, the Netherlands; [email protected] Received 22 August 2008, accepted 21 October 2008 Abstract. Fluvial deposits of Miocene to Early Pleistocene age in Germany and the Netherlands were laid down in the delta of the Eridanos River System, but the exact provenance of this material continues to be a subject of discussion. The aim of the present study is twofold. Firstly, a comparison of Ordovician sponges in these deposits with those from northern Estonia and the St Petersburg region (Russia) demonstrates that these erratics originated from the drainage area of the Pra Neva, a tributary of the Eridanos. Secondly, the importance of Late Ordovician silicified boulders, which yield forms of preservation that are unknown in comparable fossils, preserved in situ, is outlined. Some recommendations for future studies are made. Key words: Baltica, Eridanos River, erratics, Ordovician, Porifera, silicifications. INTRODUCTION sedimentary erratics as collected in the Netherlands and northern Germany. The other aim is to emphasize the Baltoscandia contributed considerably as a source area uncommon preservation of some of the fossils, which to the formation of late Cenozoic sediments in northern Germany and the Netherlands. The composition and provenance of clastics in glacial deposits of Late Pleistocene age have been described in numerous studies. This has led to the erroneous view that all clastics from Baltoscandia should be considered to have been transported by glaciers.
    [Show full text]
  • The Eridanos Delta: a Sequence Stratigraphic Study of the North Sea Upper Section with Focus on Shallow Gas Potential
    The Eridanos Delta: A Sequence Stratigraphic Study of the North Sea Upper Section with Focus on Shallow Gas Potential Majid Aljamed Copyright © 2018 Section for Applied Earth Science. Faculty of Civil Engineering & Geosciences. All rights reserved. The Eridanos Delta: A Sequence Stratigraphic Study of the North Sea Upper Section with Focus on Shallow Gas Potential Master Thesis for obtaining the degree of Master in Applied Earth Science by Majid M. Aljamed 16th August 2018 Technical University of Delft, The Netherlands. Faculty of Civil Engineering and Geoscience Supervised by Dr. Joep Storms Committee Dr. Hemmo Abels Dr. Auke Barnhoorn Acknowledgment Having reached this point, I would like to express my sincere gratitude towards everyone who contributed to my success in obtaining my Master degree including the staff of TUDelft, family, friends and Saudi Aramco. Special thanks to my supervisor Dr. Joep Storms, who took part in each phase of the project from step one, when it came to choosing a research topic that can both satisfy my learning curiosity and enhance my knowledge in a combined academic and operational manners. Joep made it possible to enjoy researching and replace feeling stressed and obligated with love to the subject and craving for better results. His unquestionable knowledge and experience surely enhanced my learning curve at TUDelft, making the thesis project the most knowledge bearing course of all. Above all, he always insisted that I have to work on topics of my interest and guided me through the research with such a unique character that is full of energy and positivity. Would also like to thank the other committee members, Dr.
    [Show full text]
  • 2009:21 the Geological History of the Baltic Sea a Review of the Literature
    Authors: Monica Beckholmen Sven A Tirén Research 2009:21The geological history of the Baltic Sea a review of the literature and investigation tools Report number: 2009:21 ISSN: 2000-0456 Available at www.stralsakerhetsmyndigheten.se Title: The geological history of the Baltic Sea a review of the literature and investigation tools. Report number: 2009:21. Authors: Monica Beckholmen ovh Sven A Tirén. Geosigma AB, Uppsala. Date: September 2008 This report concerns a study which has been conducted for the Swedish Radiation Safety Authority, SSM. The conclusions and viewpoints pre- sented in the report are those of the author/authors and do not neces- sarily coincide with those of the SSM. Background The bedrock in Sweden mainly comprises Proterozoic magmatic and metamorphic rocks older than a billion or one and a half billion years with few easily distinguished testimonies for the younger history. For construction of a geological repository for deposition of nuclear waste it is important to understand the late, brittle, geological events to be able to estimate its influence and consequences for the repository. Purpose The purpose of the current project is to compile published data related to the geological history of the Baltic Basin. The intention of the study is to contribute to the understanding and characterization of earlier and on-going and bedrock deformation in coastal areas outside Forsmark and Laxemar where the Swedish Nuclear Waste Management Co (SKB) recently has finished site investigations for a repository for spent nuclear fuel. Of special interest are structures with evident indications of late bedrock movements where also future movements cannot be excluded.
    [Show full text]
  • High Resolution Alkenone Palaeobarometry Indicates Relatively Stable Pco2 During the Pliocene (3.3 to 2.8 Ma)
    High resolution alkenone palaeobarometry indicates relatively stable pCO2 during the Pliocene (3.3 to 2.8 Ma) Marcus P.S. Badger1, Catherine.V. Davis2,3, Daniela N. Schmidt2, Andreas Mackensen4 and Richard D. Pancost1 1Organic Geochemistry Unit, The Cabot Institute and Bristol Biogeochemistry Research Centre, School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, U.K. email:[email protected] 2School of Earth Sciences, Bristol University, Wills Memorial Building, Queens Rd, Bristol, BS8 1RJ, U.K. 3now at: Bodega Marine Laboratory, University of California, Bodega Bay, CA 94923 U.S.A 4Alfred Wegener Institute for Polar and Marine Research, Am Alten Hafen 26, 27568 Bremerhaven, Germany. Temperature reconstructions indicate that the Pliocene was ~ 3 °C warmer globally than today, and several recent reconstructions of Pliocene atmospheric CO2 indicate that it was above pre-industrial levels and similar to those likely to be seen this century. However, many of these reconstructions have been of relatively low temporal resolution, meaning that these records may have failed to capture variations associated with the 41 Kyr glacial-interglacial cycles thought to operate in the Pliocene. Here we present a new, high temporal resolution alkenone carbon isotope based record of pCO2 spanning 2.8 to 3.3 million years ago from ODP Site 999. Our record is of high enough resolution (~19 Kyrs) to resolve glacial-interglacial changes beyond the intrinsic uncertainty of the proxy method. The record suggests that Pliocene CO2 levels were relatively stable, exhibiting variation less than 55 ppm. We discuss the potential influence of changing cell size or growth rate on the alkenone carbon isotopes.
    [Show full text]
  • Revised Upper Cenozoic Stratigraphy of the Dutch Sector of the North Sea
    ¥ N e Netherlands Journal of Geosciences — Geologie en Mijnbouw | 84 - 2 | 129 - 146 | 2005 Revised Upper Cenozoic stratigraphy of the Dutch sector of the North Sea Basin: towards an integrated lithostratigraphic, seismostratigraphic and allostratigraphic approach K.F. Rijsdijk , S. Passchier, H.J.T. Weerts, C. Laban, R.J.W. van Leeuwen & J.H.J. Ebbing Netherlands Institute of Applied Geoscience TNO - National Geological Survey, Princetonlaan 6, P.O. Box 80015, 3508 TA Utrecht, the Netherlands * Corresponding author. Email: [email protected] Manuscript received: February 2004; accepted: January 2005 Abstract A revised Upper Cenozoic stratigraphic framework of the Dutch sector of the North Sea Basin is presented whereby offshore stratigraphic units are integrated or correlated with onshore units. The framework is based on an integrated stratigraphic approach that combines elements of lithostratigraphy, seismostratigraphy and allostratigraphy. Offshore formations are redefined in terms of seismofacies and lithofacies associations, and are differentiated on the basis of common genesis and stratigraphic position. These facies associations represent five major depositional environments, which occur in repetitive successions in the subsurface of the Netherlands: Marine, Coastal, Glacial, Fluvial, and Local Terrestrial. Five conceptual basin-wide bounding discontinuities are identified in the North Sea-Basin that span land and sea. They are represented by both seismostratigraphic and lithostratigraphic unconformities and interpreted as surfaces that formed as a result of North Sea Basin-wide changes in depositional systems. Their formation relates to sea level rise, continental-scale glaciations, and tectonic processes. The bounding discontinuities separate informal allostratigraphic groups of formations that have a grossly uniform geologic setting in common.
    [Show full text]
  • The Late Cenozoic Eridanos Delta System in the Southern North Sea Basin: a Climate Signal in Sediment Supply? I
    Basin Research (2001) 13, 293±312 The Late Cenozoic Eridanos delta system in the Southern North Sea Basin: a climate signal in sediment supply? I. Overeem,* G. J. Weltje,* C. Bishop-Kay² and S. B. Kroonenberg* *Department of Applied Earth Sciences, Delft University of Technology, The Netherlands, PO Box 5028, NL-2600 GA Delft, The Netherlands ²Woodside Energy Ltd, 1 Adelaide Terrace, Perth WA 6000, Australia ABSTRACT The Eridanos ¯uvio-deltaic system, draining most of north-western Europe, developed during the Late Cenozoic as a result of simultaneous uplift of the Fennoscandian shield and accelerated subsidence in the North Sea Basin. This seismo-stratigraphic study aims to reconstruct the large-scale depositional architecture of the deltaic portion of the basin ®ll and relate it to external controls. A total of 27 units have been recognized. They comprise over 62r103 km3 in the Southern North Sea Basin alone, and have an average delta surface area of 28r103 km2, which suggests that the size of the drainage area was about 1.1r106 km2. Water depth in the depocentre is seen to decrease systematically over time. This trend is interrupted by a deepening phase between 6.5 and 4.5 Ma that can be correlated with the simultaneous occurrence of increased uplift of the Fennoscandian shield, increased subsidence of the Southern North Sea Basin, and a long-term eustatic highstand. All these observations point to a tectonic control on long-term average rates of accommodation and supply. Controls on short-term variations are inferred from variations in rates of sediment supply and bifurcation of the delta channel network.
    [Show full text]
  • A New Ordovician Astylospongiid Sponge (Porifera) As an Erratic from Baltica
    Netherlands Journal of Geosciences / Geologie en Mijnbouw 83 (4): 255-265 (2004) A new Ordovician astylospongiid sponge (Porifera) as an erratic from Baltica F. Rhebergen Slenerbrink 178, 7812 HJ Emmen,The Netherlands. E-mail: [email protected] Manuscript received: April 2004; accepted: October 2004 G Abstract Until now hemispherical astylospongiid sponges were invariably referred to as Caryospongia juglans var. basiplana Rauff. Renewed investigations have now shown that part of the material should be assigned to a new genus and species, Tympanospongia vankempeni, which is characterised by a system of very irregular canals. These flat-based sponges originate from the Baltic region and occur in two assemblages of silicified Late Ordovician sponges known exclusively as erratics from The Netherlands and northern Germany. These fossils were transported by the River Eridanos, a former drainage system from the Baltic region that filled the North European Basin during the Miocene to Early Pleistocene. Specimens of Tympanospongia vankempeni gen. et sp. nov. also occur in the Upper Pleistocene of Gotland, Sweden. The new sponge described herein principally differs from other genera of the Astylospongiidae found frequently in the erratic sponge assemblages by its irregular system of apochetes which ramify and anastomose commonly. Keywords: Porifera, astylospongiids, Baltica, erratics, Late Ordovician, new taxa Introduction southeast of Berlin, Germany (Bijlsma, 1981; Krueger, 1994) and from Pliocene to Lower Pleistocene de­ Fluvial deposits in The Netherlands and northern posits until recently exposed in sandpits on the island Germany have yielded thousands of erratic sponges of of Sylt, northern Germany (Von Hacht, 1985, 1994; Middle and Late Ordovician age (Van Kempen, Von Hacht & Rhebergen, 1996).
    [Show full text]
  • A New Age Model for the Pliocene of the Southern North Sea Basin: a Multi Proxy Climate Reconstruction
    A new age model for the Pliocene of the Southern North Sea Basin: a multi proxy climate reconstruction Emily Dearing Crampton-Flood1*, Lars J. Noorbergen2, Damian Smits1, R. Christine Boschman1, Timme H. Donders4, Dirk K. Munsterman5, Johan ten Veen5, Francien Peterse1, 5 Lucas Lourens1, Jaap S. Sinninghe Damsté1,3 1Department of Earth Sciences, Utrecht University, Utrecht, The Netherlands 2Department of Earth Sciences, VU University Amsterdam, Amsterdam, The Netherlands 3Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research and Utrecht University, The Netherlands 10 4Department of Physical Geography, Utrecht University, Utrecht, The Netherlands 5TNO-Geological Survey of the Netherlands, Utrecht, The Netherlands Correspondence to: Emily Dearing Crampton-Flood ([email protected]) *Present address: School of Earth and Environmental Sciences, The University of Manchester, Manchester, The United Kingdom 15 Abstract The mid-Piacenzian Warm Period (mPWP, 3264–3025 ka) represents the most recent interval in Earth’s history where atmospheric CO2 levels were similar to today. The reconstruction of sea surface temperatures (SSTs) and climate modelling studies have shown that global 20 temperatures were 2–4 °C warmer than present. However, detailed reconstructions of marginal seas and/or coastal zones, linking the coastal and continental climate evolution, are lacking. This is in part due to the absence of precise age models for coastal sedimentary successions, as they are generally formed by dynamic depositional systems with varying sediment and freshwater inputs. Here, we present a multi-proxy record of Pliocene climate change in the 25 coastal Southern North Sea Basin (SNSB) based on the sedimentary record from borehole Hank, the Netherlands.
    [Show full text]
  • A New Age Model for the Pliocene of the Southern North Sea Basin: Evidence for Asynchronous Shifts of Marine and Terrestrial Climate
    Clim. Past Discuss., https://doi.org/10.5194/cp-2019-39 Manuscript under review for journal Clim. Past Discussion started: 8 April 2019 c Author(s) 2019. CC BY 4.0 License. A new age model for the Pliocene of the Southern North Sea Basin: evidence for asynchronous shifts of marine and terrestrial climate Emily Dearing Crampton-Flood1*, Lars J. Noorbergen2, Damian Smits1, R. Christine 5 Boschman1, Timme H. Donders4, Dirk K. Munsterman5, Johan ten Veen5, Francien Peterse1, Lucas Lourens1, Jaap S. Sinninghe Damsté1,3 1Department of Earth Sciences, Utrecht University, Utrecht, The Netherlands 2Department of Earth Sciences, VU University Amsterdam, Amsterdam, The Netherlands 3Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research 10 and Utrecht University, The Netherlands 4Department of Physical Geography, Utrecht University, Utrecht, The Netherlands 5TNO-Geological Survey of the Netherlands, Utrecht, The Netherlands Correspondence to: Emily Dearing Crampton-Flood ([email protected]) *Present address: School of Earth and Environmental Sciences, The University of Manchester, Manchester, The 15 United Kingdom Abstract The mid-Pliocene Warm Period (mPWP, 3254–3025 ka) represents the most recent interval in Earth’s history where atmospheric CO2 levels were similar to today. The reconstruction of sea 20 surface temperatures (SSTs) and modeling studies have shown that global temperatures were 2–4 °C warmer than present. However, detailed reconstructions of marginal seas and/or coastal zones that enable linking climate evolution in the marine realm to that on the continents are lacking. This is in part due to the absence of precise age models for coastal zones, as they are generally dynamic systems with varying sediment and fresh water inputs.
    [Show full text]