All ICDP Publications with Abstracts
From parent-sysfolder "Publications" + 2 folder-levels deep
1744.
Trans-Amazon Drilling Project (TADP): Origins and evolution of the forests, climate, and hydrology of the South American tropics
Scientific Drilling,
2041-49
2015
ISSN: 18168957
Publisher: Copernicus GmbH
Keywords:▾
Biodiversity; Drills; Plants (botany); Rivers; Sedimentology; Settling tanks, Brazilian Amazon; Cenozoic history; Drilling projects; Landscape evolutions; Physical environments; Plant diversity; Sedimentary basin; Sedimentary records, Forestry
Abstract: ▾ This article presents the scientific rationale for an ambitious ICDP drilling project to continuously sample Late Cretaceous to modern sediment in four different sedimentary basins that transect the equatorial Amazon of Brazil, from the Andean foreland to the Atlantic Ocean. The goals of this project are to document the evolution of plant biodiversity in the Amazon forests and to relate biotic diversification to changes in the physical environment, including climate, tectonism, and the surface landscape. These goals require long sedimentary records from each of the major sedimentary basins across the heart of the Brazilian Amazon, which can only be obtained by drilling because of the scarcity of Cenozoic outcrops. The proposed drilling will provide the first long, nearly continuous regional records of the Cenozoic history of the forests, their plant diversity, and the associated changes in climate and environment. It also will address fundamental questions about landscape evolution, including the history of Andean uplift and erosion as recorded in Andean foreland basins and the development of west-to-east hydrologic continuity between the Andes, the Amazon lowlands, and the equatorial Atlantic. Because many modern rivers of the Amazon basin flow along the major axes of the old sedimentary basins, we plan to locate drill sites on the margin of large rivers and to access the targeted drill sites by navigation along these rivers. © Author(s) 2015.
1743.
Mid-latitude terrestrial climate of East Asia linked to global climate in the Late Cretaceous
Geology,
43
(4)
287-290
2015
ISSN: 00917613
Publisher: Geological Society of America
DOI:10.1130/G36427.1
Keywords:▾
Greenhouses; Isotopes; Temperature, Carbon isotopes; Climate variability; Climatic signals; Greenhouse climates; Increasing temperatures; Pedogenic carbonates; Primary productivity; Warming climate, Glacial geology, carbon isotope; carbonate; climate variation; Cretaceous; global climate; midlatitude environment; oxygen isotope; paleoclimate; stable isotope, China; Far East; Songliao Basin
Abstract: ▾ The Late Cretaceous (late Campanian to Maastrichtian) was characterized by a variable greenhouse climate, with evidence for cooling and/or glaciation and warming events. Most of these climatic signals are derived from marine records, and knowledge of the terrestrial climate, especially in the mid-latitudes, is limited due to fragmentary geological records on continents. Here we report mid-latitude terrestrial stable oxygen and carbon isotope data from pedogenic carbonates in the nearly continuous Late Cretaceous age SK-1 core drilled in the Songliao Basin, northeastern China. Our data indicate a punctuated, mid-latitude terrestrial climate in the Late Cretaceous. We interpret the negative excursion of pedogenic carbonate δ18O in the early Maastrichtian to be the result of decreasing temperature and/or strengthened westerlies during global cooling and possible glaciation, providing valuable mid-latitude terrestrial evidence for this event. The negative δ13C isotopic excursion ca. 66 Ma is modeled as higher primary productivity caused by increasing temperature and precipitation in response to a warming climate in the latest Cretaceous. Our continuous stable isotopic records in the Songliao Basin are in accordance with previously published global Late Cretaceous records of climate variability from marine and terrestrial regions, and demonstrate the sensitivity of mid-latitude terrestrial climate in a greenhouse world. © 2015 Geological Society of America.
1742.
Geophysical studies of the upper crust of the central Swedish Caledonides in relation to the COSC scientific drilling project
Ph.{D}. thesis
Ph.{D}. thesis
Uppsala University,
Uppsala, Sweden
2015
1741.
The derivation of an anisotropic velocity model from a combined surface and borehole seismic survey at the COSC-1 borehole, central Sweden
Page H11B--1327
Publisher
American Geophysical Union
,
San Francisco
2015
1740.
[English]
Thermal and trace-element anomalies in the eastern snake river plain aquifer: Toward a conceptual model of the EGS resource
Volume 39
,
Page 363-375
Publisher
Geothermal Resources Council
2015
Idaho Geological Survey, Idaho State University, Pocatello, ID, United StatesISBN:
9781510817241
1739.
[English]
Remnants of early Archean impact deposits on earth: Search for a meteoritic component in the BARB5 and CT3 drill cores (Barberton Greenstone Belt, South Africa)
Volume 103
,
Page 310 – 317
In Schonberg W.P.,
Editor
Publisher
Elsevier Ltd
2015
Keywords:▾
Aggregates; Core drilling; Deposits; Drills; Iridium; Isotopes; Meteorites; Osmium; Archean; Greenstone belts; Highly siderophile elements; Osmium isotopes; spherules; Matrix algebra
1738.
Snake river plain
Publisher
Princeton University Press
2015
ISBN:
9781400876525; 9780691624426
1737.
Exogenic Dynamics, Cratering, and Surface Ages
Volume 10
2015
1736.
A History of Exploration for and Discovery of Finland's Ore Deposits
Publisher
Elsevier Inc.
2015
Keywords:▾
Copper nickel deposits; Copper zinc deposits; Deposits; Diamond drilling; Economic geology; Geological surveys; History; Iron deposits; Military operations; Mineral exploration; Mineral industry; Natural resources exploration; Nickel; Nickel deposits; Ore deposits; Ores; Phosphate minerals; Tin deposits; Titanium deposits; Vanadium deposits; Domestic industries; Exploration company; Exploration methods; Finland; Geophysical measurements; Outokumpu Oy; Rautaruukki Oy; Scientific exploration; Gold deposits
ISBN:
978-012410476-1; 978-012410438-9
1735.
Zero-Offset VSP in the COSC-1 borehole
Geophysical Research Abstracts,
17EGU2015--3255
2015
1734.
When was the Earth's conveyor belt set in motion?
American Mineralogist,
100
(11-12)
2369 – 2370
2015
ISSN: 0003004X
Publisher: Walter de Gruyter GmbH
Keywords:▾
Barberton Greenstone Belt; Belt conveyors; Binary alloys; Earth (planet); Isotopes; Lutetium alloys; Neodymium alloys; Samarium alloys; Tectonics; Trace elements; Barberton; Conveyor belts; Element signatures; Greenstone belts; Hf isotope; Isotopic systems; Pelagic sediments; subduction; greenstone belt; hafnium; isotopic analysis; komatiite; lutetium; neodymium; plate tectonics; samarium-neodymium dating; subduction; Hafnium alloys
Abstract: ▾ The start of plate tectonics on Earth is one of the most controversial issues in modern geology, with proposed timings covering almost the entire history of our planet. On page 2387 of this issue (vol. 100, 2015), Blichert-Toft and co-authors report Sm-Nd and Lu-Hf isotopic and lithophile trace element data for early Archean komatiites from the Barberton Greenstone Belt (GB) in South Africa, and argue for the onset of plate tectonics on Earth as early as 3.5 Ga. The studied komatiites show a large decoupling of the two isotopic systems and lithophile trace element signatures that are most consistent with deep-water, pelagic sediments being present in the lower-mantle source of these lavas. Their conclusions have far-reaching implications for advancing our understanding of how the Earth system operated in the distant geological past. © Walter de Gruyter Berlin/Boston 2015.
1733.
Volatiles in magmas related to the Campanian Ignimbrite eruption: Experiments vs. natural findings
American Mineralogist,
100
(10)
2284 – 2297
2015
ISSN: 0003004X
Publisher: Walter de Gruyter GmbH
Keywords:▾
Campania [Italy]; Campi Flegrei; Italy; Napoli [Campania]; Trachytes; Carbon dioxide process; Digital storage; Glass; Isotopes; Ponding; Solubility; Storage (materials); Uncertainty analysis; Volcanoes; Water; Campanian Ignimbrite; Hydrogen isotope; Solchiaro eruption; trachybasalt; trachyte; Volcanic district; Campanian; carbon dioxide; hydrogen isotope; ignimbrite; isotopic fractionation; magma chemistry; solubility; trachyte; volatile substance; volcanic eruption; water content; Carbon dioxide
Abstract: ▾ The solubility of H2O- and CO2-bearing fluids in trachytic and trachybasaltic melts from erupted magmas of the Campi Flegrei Volcanic District has been investigated experimentally at 1100 and 1200 °C, respectively, and at 100, 200, 300, 400, and 500 MPa. The solubility of H2O in the investigated melts varies between 3.48 ± 0.07 wt% at 100 MPa to 10.76 ± 0.12 wt% at 500 MPa in trachytic melts and from 3.49 ± 0.07 wt% at 100 MPa to 9.10 ± 0.11 wt% at 500 MPa in trachybasaltic melts. The content of dissolved CO2 in melts coexisting with the most CO2-rich fluid phase increases from 281 ± 24 ppm at 100 MPa to 2710 ± 99 ppm at 500 MPa in trachyte, and from 727 ± 102 ppm at 100 MPa to 3565 ± 111 ppm at 500 MPa in trachybasalt. Natural samples from the Campanian Ignimbrite eruption (trachyte) and from the Solchiaro eruption (trachybasalt) were collected around the city of Naples and on Procida Island. Deuterium/hydrogen (D/H) ratios were analyzed in natural pumices pre-heated at different temperatures to remove water adsorbed and/or imprinted by glass alteration processes. It has been determined that heating of the glass to 350 °C efficiently removes most of secondary water and the remaining concentrations represent primary magmatic water preserved in the erupted material. Hydrogen isotope composition (with δD values ranging between -70‰ and -110‰) and its correlation with bulk water content in selected pumice samples of the Campanian Ignimbrite eruption are consistent with isotopic fractionation between magmatic fluid and melt during degassing of erupting magma. Hence, the H2O and CO2 contents in natural glasses from pumice samples are considered as minimum estimates on volatile concentrations in the melt just prior to the eruption or at the fragmentation event. The water contents in natural glasses vary from 0.83 ± 0.07 to 3.74 ± 0.06 wt% for trachytes from the Campanian Ignimbrite eruption and from 1.96 ± 0.06 to 3.47 ± 0.07 wt% for trachybasalts from the Solchiaro eruption. The CO2 contents vary from 78 ± 120 ppm CO2 to 1743 ± 274 ppm for trachytes from the Campanian Ignimbrite eruption and from 240 ± 293 to 1213 ± 250 ppm for trachybasalts from the Solchiaro eruption. A combination of natural and experimental data provides minimum pressure estimates for the storage and ascent conditions of magmas. The Campanian Ignimbrite magma could have been stored or ponded during its rising path at two different levels: a deeper one corresponding to depth of about 8 to 15 km and a shallower one at about 1 to 8 km. Trachybasalts from Solchiaro erupted from the deepest level of about 11 km with a storage or ponding level at around 2 to 8 km depth. Although an uncertainty of at least a kilometer has to be considered in estimating storage or ponding depths, these estimates point to significantly deeper magmatic sources for both eruptions as those considered previously. © 2015 by Walter de Gruyter Berlin/Boston.
1732.
Vegetation and environmental changes during the last interglacial in eastern Anatolia (Turkey): A new high-resolution pollen record from Lake Van
Palaeogeography, Palaeoclimatology, Palaeoecology,
435145-158
2015
ISSN: 00310182
Publisher: Elsevier
Keywords:▾
abundance; climate conditions; climate variation; community structure; coniferous tree; data set; deciduous tree; environmental change; environmental history; lacustrine deposit; Last Interglacial; oxygen isotope; paleoecology; palynology; pollen; proxy climate record; resolution; stable isotope; steppe; succession; temperature effect; vegetation structure; X-ray fluorescence, Anatolia; Arctic; Greenland; Greenland Ice Sheet; Lake Van; Turkey, Carpinus; Pistacia; Quercus; Ulmus
Abstract: ▾ A high-resolution multi-proxy record from Lake Van, eastern Anatolia, derived from a lacustrine sequence cored at the 357m deep Ahlat Ridge (AR), allows a comprehensive view of paleoclimate and environmental history in the continental Near East during the last interglacial (LI). We combined paleovegetation (pollen), stable oxygen isotope (δ18Obulk) and XRF data from the same sedimentary sequence, showing distinct variations during the period from 135 to 110ka ago leading into and out of full interglacial conditions. The last interglacial plateau, as defined by the presence of thermophilous steppe-forest communities, lasted ca. 13.5ka, from ~129.1-115.6ka BP.The detailed palynological sequence at Lake Van documents a vegetation succession with several climatic phases: (I) the Pistacia zone (ca. 131.2-129.1. ka BP) indicates summer dryness and mild winter conditions during the initial warming, (II) the Quercus-. Ulmus zone (ca. 129.1-127.2. ka BP) occurred during warm and humid climate conditions with enhanced evaporation, (III) the Carpinus zone (ca. 127.2-124.1. ka BP) suggest increasingly cooler and wetter conditions, and (IV) the expansion of Pinus at ~. 124.1. ka BP marks the onset of a colder/drier environment that extended into the interval of global ice growth. Pollen data suggest migration of thermophilous trees from refugial areas at the beginning of the last interglacial. Analogous to the current interglacial, the migration documents a time lag between the onset of climatic amelioration and the establishment of an oak steppe-forest, spanning 2.1. ka. Hence, the major difference between the last interglacial compared to the current interglacial (Holocene) is the abundance of Pinus as well as the decrease of deciduous broad-leaved trees, indicating higher continentality during the last interglacial. Finally, our results demonstrate intra-interglacial variability in the low mid-latitudes and suggest a close connection with the high-frequency climate variability recorded in Greenland ice cores. © 2015 Elsevier B.V.
1731.
Variation of magnetic properties in sediments from Lake Towuti, Indonesia, and its paleoclimatic significance
Palaeogeography, Palaeoclimatology, Palaeoecology,
420163 – 172
2015
ISSN: 00310182
Publisher: Elsevier
Keywords:▾
Greater Sunda Islands; Lake Towuti; Malili Lakes; South Sulawesi; Sulawesi; Sunda Isles; clastic sediment; core analysis; depositional environment; dissolution; Holocene; lacustrine deposit; magnetic mineral; magnetic property; marine isotope stage; ophiolite; paleoclimate; sediment property
Abstract: ▾ We investigated the mineral-magnetic behavior of sediments from Lake Towuti located in the Eastern Sulawesi Ophiolite belt, Indonesia. Rock magnetic analysis supplemented by X-ray diffraction and scanning electron microscopy analysis were performed on sediment core TOW10-9B from the north basin of Lake Towuti to give insights on the environmental and sedimentary processes controlling the magnetic properties of the sediment and its paleoclimatic significance. The results show that the core has three distinct zones of varying magnetic properties. Careful examination demonstrates that these zones correspond to varying levels of iron oxide dissolution and magnetite precipitation that are climatically and environmentally dependent. The magnetically strongest zone is characterized by weak iron oxide dissolution and intense magnetite precipitation, likely driven by changes in the stratification and/or water level of the lake during dry conditions in Marine Isotope Stage 2 (MIS2) period, whereas the two magnetically weaker zones are characterized by signs of dissolution and correspond to relatively wet conditions, respectively, during Marine Isotope Stage 3 (MIS3) and the Holocene. Although our data show that major changes in concentration dependent parameters, such as magnetic susceptibility and saturation isothermal remanent magnetization (SIRM), in Lake Towuti sediment correlate with changes in regional rainfall, many of the concentration changes are more strongly affected by in situ chemical processes than by changes in erosion and terrestrial sediment supply. These findings urge caution in the interpretation of magnetic mineral concentration profiles as indicators of clastic sediment inputs. © 2014 Elsevier B.V.
1730.
Time-lapse characterization of hydrothermal seawater and microbial interactions with basaltic tephra at Surtsey Volcano
Scientific Drilling,
2051-58
2015
ISSN: 18168957
Publisher: Copernicus GmbH
Keywords:▾
Biology; Deposits; Drills; Volcanoes, Basaltic eruptions; Environment Agency; Hydrothermal conditions; Logistical support; Long term performance; Microbial colonization; Microbial interactions; Scientific objectives, Basalt
Abstract: ▾ A new International Continental Drilling Program (ICDP) project will drill through the 50-year-old edifice of Surtsey Volcano, the youngest of the Vestmannaeyjar Islands along the south coast of Iceland, to perform interdisciplinary time-lapse investigations of hydrothermal and microbial interactions with basaltic tephra. The volcano, created in 1963-1967 by submarine and subaerial basaltic eruptions, was first drilled in 1979. In October 2014, a workshop funded by the ICDP convened 24 scientists from 10 countries for 3 and a half days on Heimaey Island to develop scientific objectives, site the drill holes, and organize logistical support. Representatives of the Surtsey Research Society and Environment Agency of Iceland also participated. Scientific themes focus on further determinations of the structure and eruptive processes of the type locality of Surtseyan volcanism, descriptions of changes in fluid geochemistry and microbial colonization of the subterrestrial deposits since drilling 35 years ago, and monitoring the evolution of hydrothermal and biological processes within the tephra deposits far into the future through the installation of a Surtsey subsurface observatory. The tephra deposits provide a geologic analog for developing specialty concretes with pyroclastic rock and evaluating their long-term performance under diverse hydrothermal conditions. Abstracts of research projects are posted at http://surtsey. icdp-online.org. © Author(s) 2015.
1729.
Strontium and oxygen isotopic profiles through 3km of hydrothermally altered oceanic crust in the Reykjanes Geothermal System, Iceland
Chemical Geology,
41234-47
2015
ISSN: 00092541
Publisher: Elsevier
Keywords:▾
Aluminum; Basalt; Crystalline rocks; Geothermal fields; Isotopes; Laser ablation; Minerals; Oxygen; Rocks; Seawater; Silicate minerals, Alteration; Geothermal; Hydrothermal; Icelands; Oxygen isotopes; Reykjanes; Strontium isotopes, Strontium, concentration (composition); geothermal system; hydrothermal alteration; hydrothermal fluid; hydrothermal vent; isotopic composition; mid-ocean ridge basalt; oceanic crust; oxygen isotope; strontium isotope, East Pacific Rise; Iceland; Pacific Ocean; Reykjanes Peninsula
Abstract: ▾ The Iceland Deep Drilling Program well RN-17 was drilled 3km into a section of hydrothermally altered basaltic crust in the Reykjanes geothermal system in Iceland. The system is located on the landward extension of the Mid-Atlantic Ridge, and the circulating hydrothermal fluid is modified seawater, making Reykjanes a useful analog for mid-oceanic ridge hydrothermal systems. We have determined whole-rock Sr and O isotope compositions, and Sr isotope compositions of epidote grains from the RN-17 cuttings and RN-17B core. Whole rock oxygen isotope ratios range from -0.13 to 3.61‰ V-SMOW, and are isotopically lighter than fresh MORB (5.8±0.2‰). The concentrations of Sr in the altered basalt range from well below to well above concentrations in fresh rock, and appear to be strongly correlated with the dominant alteration mineralogy. Whole rock Sr isotope ratios ranged from 0.70329 in the least altered crystalline basalt, to 0.70609 in the most altered hyaloclastite samples; there is no correlation with depth. Sr isotope ratios in epidote grains measured by laser ablation MC-ICP-MS ranged from 0.70360 to 0.70731. Three depth intervals, at 1000m, 1350m, and 1650m depth, have distinctive isotopic signatures, where 87Sr/86Sr ratios are elevated (mean value>0.7050) relative to background levels (mean altered basalt value ~0.7042). These areas are proximal to geothermal feed zones, and the 1350m interval directly overlies the transition from dominantly extrusive to dominantly intrusive lithologies. Oxygen isotope measurements yield integrated water/rock ratios of 0.4 to 4.3, and suggest that hydrothermal fluids must have formerly had a component of meteoric water. Strontium isotopic measurements provide a more sensitive indication of seawater interaction and require significant exchange with seawater strontium. Both isotopic systems indicate that the greenschist-altered basalts were in equilibrium with hydrothermal fluids at a relatively high mean water/rock (Wt.) ratio ranging from about 0.5 to 4. These ratios are higher than estimates from ODP Hole 504B and IODP Hole 1256D, but are consistent with values inferred from vent fluids from 21° and 13°N on the East Pacific Rise (Albarède et al., 1981; Michard et al., 1984; Alt et al., 1996; Harris et al., 2015). © 2015 Elsevier B.V.
1728.
1727.
The rheological behaviour of fracture-filling cherts: Example of Barite Valley dikes, Barberton Greenstone Belt, South Africa
Solid Earth,
6
(1)
253 – 269
2015
ISSN: 18699510
Publisher: Copernicus GmbH
Keywords:▾
Barberton Greenstone Belt; Complex networks; Fracture; Fracturing fluids; Gelation; Hydraulic fracturing; Hydraulic structures; Levees; Silica; Temperature; Viscosity; Colloidal structures; Isotopic composition; Microscopic structures; Multiple injections; Physical characteristics; Rheological behaviour; Rheological property; Volcano-sedimentary sequences; Archean; chert; dike; fracture; greenstone belt; isotopic composition; rheology; viscosity; Suspensions (fluids)
Abstract: ▾ In the Barberton Greenstone Belt, South Africa, a 100-250 m thick complex of carbonaceous chert dikes marks the transition from the Mendon Formation to the Mapepe Formation (3260 Ma). The sub-vertical-to vertical position of the fractures, the abundance of highly shattered zones with poorly rotated angular fragments and common jigsaw fit, radial structures, and multiple injection features point to repetitive hydraulic fracturing that released overpressured fluids trapped within the shallow crust. The chemical and isotopic compositions of the chert favour a model whereby seawater-derived fluids circulated at low temperature (< 100-150 °C) within the shallow crust. From the microscopic structure of the chert, the injected material was a slurry of abundant clay-sized, rounded particles of silica, carbonaceous matter and minor clay minerals, all suspended in a siliceous colloidal solution. The dike geometry and characteristics of the slurry concur on that the chert was viscoelastic, and most probably thixotropic at the time of injection: the penetration of black chert into extremely fine fractures is evidence for low viscosity at the time of injection and the suspension of large country rock fragments in the chert matrix provides evidence of high viscosity soon thereafter. We explain the rheology by the particulate and colloidal structure of the slurry, and by the characteristic of silica suspensions to form cohesive 3-D networks through gelation. <br><br> Our results provide valuable information about the compositions, physical characteristics and rheological properties of the fluids that circulated through Archean volcano-sedimentary sequences, which is an additional step to understand conditions on the floor of Archean oceans, the habitat of early life.
1726.
The Réunion Subchron vegetation and climate history of the northeastern Russian Arctic inferred from the Lake El'gygytgyn pollen record
Palaeogeography, Palaeoclimatology, Palaeoecology,
436167-177
2015
ISSN: 00310182
Publisher: Elsevier
Keywords:▾
biome; climate variation; environmental change; interglacial; lake ecosystem; paleoclimate; paleoecology; paleoenvironment; palynology; Pleistocene; regional pattern; succession; vegetation history; deciduous forest; green alga; marine isotope stage; orbital forcing; precession; reconstruction; steppe, Chukchi; Elgygytgyn Lake; Mascarene Islands; Reunion; Russian Federation; Arctic
Abstract: ▾ The 318-m-thick sediment record from Lake El'gygytgyn provides unique opportunities for a detailed examination of environmental changes during the Réunion Subchron polarity reversal event (2.1384-2.1216. Myr. BP) in the northeastern Russian Arctic. The paper describes vegetation and climate fluctuations between ~. 2.15 and 2.10. Myr. BP as inferred from palynological data. Biome reconstructions indicate that throughout this interval the tundra (TUND) biome generally has higher affinity scores as compared to cold steppe (STEP) or cold deciduous forest (CLDE). An exception is the climatic optimum between ~. 2.139 and 2.131. Myr. BP, coinciding with Marine Isotope Stage 81 (approximately the Réunion Subchron), when the CLDE biome has the highest scores. Landscape-openness indices suggest that more closed vegetation characterized most of the interval between 2.146 and 2.127. Myr. BP, when deciduous forest and shrubs expanded in the regional vegetation and climate was relatively warm and wet. Peaks in green algal colonies (Botryococcus) and Zygnema-type spores ~. 2.150-2.146, ~. 2.131-2.123, and ~. 2.112-2.102. Myr. BP indicate expansions of shallow-water habitats and lowered lake levels. Comparisons with biome reconstructions from other interglacial intervals at Lake El'gygytgyn suggest that precession-related summer insolation intensity and obliquity-related duration of summer daylight are major controls on the onset of interglaciations, whereas obliquity probably plays a more significant role on vegetation succession at northern high latitudes during the Pleistocene. © 2015 Elsevier B.V.
1725.
The palynological record from Coniacian to lower Campanian continental sequences in the Songliao Basin, northeastern China and its implications for palaeoclimate
Cretaceous Research,
56226-236
2015
ISSN: 01956671
Publisher: Academic Press
Keywords:▾
Campanian; climate variation; Coniacian; flora; geological record; paleoclimate; palynology; proxy climate record; sequence stratigraphy; temperate environment, China; Songliao Basin, Gymnospermae; Magnoliophyta; Pteridophyta
Abstract: ▾ A palynological record recovered from successions of Coniacian to early Campanian age (89.1-83.5Ma) was obtained from the lacustrine sequences of the SK-I south core (SK-Is) in the Songliao Basin, northeastern China. The palynoflora is dominated by bisaccate gymnosperm pollen, followed by spores of pteridophytes, and just minor amounts of angiosperm pollen. Based on the relative abundance of the different spore and pollen taxa through the core, the succession was subdivided into three palynological assemblages. The results indicate two opposite trends for climate change, a minor warming trend (from 89.1 to 85.7Ma) followed by a rapid cooling trend (85.7-83.5Ma). The first warming trend reached its maximum at 85.7Ma, which is inconsistent with results from the marine realm (which instead show a minor cooling trend based on several proxy records). However, the second cooling phase is consistent with global changes from various and abundant palaeoclimate proxies from marine deposits. We interpret the climatic changes within the studied interval (89.1-83.5Ma) as a consequence of the shifting climate from a hot/super greenhouse to a temperate greenhouse. © 2015 Elsevier Ltd.
1724.
The organic geochemical evidences for the lake water stratification in Lower Nenjiang Formation, Songliao Basin
Journal of Lake Sciences,
27190-194
012015
1723.
The distribution of polycyclic aromatic hydrocarbons (PAHs) in sediments from Upper Cretaceous Nenjiang Formation of Songliao Basin and its paleoclimate significance
Geochimica,
44536-545
2015
1722.
The Cretaceous Songliao Basin: Dynamic background from volcanic rift to interior sag basin.
Earth Science Frontiers,
22
(3)
99-117
2015
ISSN: 10052321
Publisher: Science Frontiers editorial department
Keywords:▾
Classification (of information); Faulting; Geodynamics; Stratigraphy; Volcanoes, Continental scientific drillings; Integrated informations; North China; Songliao basin; Stratigraphic units; Systematical analysis; Tectonic evolution; Volcanic rifts, Plates (structural components)
Abstract: ▾ On the basis of the new results of the CCSD (China Cretaceous Continental Scientific Drilling) and the integrated information concerning tectonic basin classification and 3-D description of the Songliao Basin (SB), we reevaluate the type, tectonic evolution, and geodynamics of the SB according to systematical analysis of tectonic setting and basin fillings. The SB is on the northeast marginal zone of Mongolia-North China Plate. It is united with the Siberian Plate by the Mongolia-Okhotsk suture belt to the north, and connected with the Pacific Plate by Sikhote-Alin accretionary belt to the east. The vertical filling successions of the SB can be subdivided into three tectono-stratigraphic units by two regional unconformities which are on the top boundaries of the Yingcheng (K1y) (ca. 110 Ma) and Nenjiang (K2n) (ca. 79.1 Ma) Formations, respectively. The three tectono-stratigraphic units are block faulting (Huoshiling to Yingcheng Formations), interior sag (Denglouku to Nenjiang Formations), and structural inversion (Sifangtai to Yi'an Formations) sequences. The block faulting sequence is a kind of volcanic rift basin, and the latter two all belong to the type of interior sag basin. In the block faulting period (150-110 Ma), syn-rift volcanogenic successions were formed under the impact of regional extension that may be caused by the Plate reorganization from two sides, the northern and eastern active continental margins. The post-rift basin fills (110-79.1 Ma) may result from the superimposed subsidence of both post volcanic thermal declining and regional strike-slip pull-apart effect. Widespread and thick source rocks deposited because of the high rate and under-compensation of sedimentation in this period. In the structural inversion period (79.1-40 Ma), depocenter of the SB migrated northwestward, and the basin was shrinking to demise. This was a result of the regional compression that should be caused by the Pacific Plate subduction under the eastern margin of the Eurasian Plate in the Mid-Cretaceous to the Middle Eocene. ©, 2015, The Editorial Office of Earth Science Frontiers. All right reserved.
1721.
The China continental scientific drilling project: CCSD-1 well drilling engineering and construction
Springer Geology
2015
ISSN: 21979545
Publisher: Springer
1720.
The carbon isotopic composition of individual biomarkers in lacustrine source rocks from Songliao Basin and its biogeochemical implication
Geochimica,
44
(4)
337-347
2015