All ICDP Publications with Abstracts
From parent-sysfolder "Publications" + 2 folder-levels deep
2709.
Syn-rift to post-rift tectonic transition and drainage reorganization in continental rifting basins: Detrital zircon analysis from the Songliao Basin, NE China
Geoscience Frontiers,
13
(3)
2022
2708.
The Chicxulub impact and its environmental consequences
NATURE REVIEWS EARTH & ENVIRONMENT,
3
(5)
338-354
2022
Abstract: ▾ The extinction of the dinosaurs and around three-quarters of all living species was almost certainly caused by a large asteroid impact 66 million years ago. Seismic data acquired across the impact site in Mexico have provided spectacular images of the approximately 200-kilometre-wide Chicxulub impact structure. In this Review, we show how studying the impact site at Chicxulub has advanced our understanding of formation of large craters and the environmental and palaeontological consequences of this impact. The Chicxulub crater’s asymmetric shape and size suggest an oblique impact and an impact energy of about 1023 joules, information that is important for quantifying the climatic effects of the impact. Several thousand gigatonnes of asteroidal and target material were ejected at velocities exceeding 5 kilometres per second, forming a fast-moving cloud that transported dust, soot and sulfate aerosols around the Earth within hours. These impact ejecta and soot from global wildfires blocked sunlight and caused global cooling, thus explaining the severity and abruptness of the mass extinction. However, it remains uncertain whether this impact winter lasted for many months or for more than a decade. Further combined palaeontological and proxy studies of expanded Cretaceous–Palaeogene transitions should further constrain the climatic response and the precise cause and selectivity of the extinction. © 2022, Springer Nature Limited.
2707.
The Effect of Correlated Permeability on Fluid-Induced Seismicity
Geophysical Research Letters,
49
(4)
2022
2706.
The post-Caledonian thermo-tectonic evolution of Fennoscandia
Gondwana Research,
107201--234
2022
ISSN: 1342-937XKeywords:▾
Exhumation, AFTA, Craton, Missing section, Peneplain
Abstract: ▾ The evolution of Fennoscandia following the early Devonian collapse of the Caledonian mountains is a matter of debate, due largely to the scarcity of post-Caledonian cover rocks. The preserved geological record therefore provides only partial documentation of the geological evolution. A more complete understanding is obtained by also considering evidence of rocks that were formerly present but have since been removed. We report apatite fission track data and associated thermal history constraints in 331 samples of Precambrian basement, younger sedimentary cover, Paleozoic and Mesozoic igneous rocks from outcrops and boreholes (up to 6 km depth) across Fennoscandia, which define thirteen phases of cooling (each representing kilometre-scale exhumation) over the last 1100 Myr. Key post-Caledonian episodes began in the intervals 311–307 Ma (late Carboniferous), 245–244 Ma (Middle Triassic), 170–167 Ma (Middle Jurassic), 102–92 Ma (mid-Cretaceous) and 23–21 Ma (early Miocene). These episodes, varying in magnitude, are recognised across Fennoscandia, and their effects are documented in the stratigraphic record and as prominent regional peneplains. The results define a history involving repeated episodes of regional burial and exhumation. Major offsets in Mesozoic paleotemperatures over short distances define kilometre-scale differential vertical displacements, emphasising the tectonic nature of the history. Results from Finland record the same events recognised in Norway and Sweden (though less pronounced), and are not consistent with long-term cratonic stability. The lack of preserved Phanerozoic sedimentary cover in Finland is interpreted to be due to complete removal during multiple episodes of denudation. In southern Norway and Sweden, early Miocene exhumation led to creation of a peneplain, which in Pliocene times was uplifted and dissected, producing the modern landscape. Post-Caledonian exhumation episodes defined here are broadly synchronous with similar events in Greenland, the British Isles and North America. Far-field transmission of plate-tectonic stress and/or mantle processes may explain the vertical movements described here.
2705.
Thermal History of Lithosphere Formed Beneath Fast Spreading Ridges: Constraints From the Mantle Transition Zone of the East Pacific Rise at Hess Deep and Oman Drilling Project, Wadi Zeeb, Samail Ophiolite
Journal of Geophysical Research: Solid Earth,
127
(1)
e2021JB022696
2022
ISSN: 21699313
Publisher: Wiley Online Library
Keywords:▾
gabbro; hydrothermal alteration; mantle source; ophiolite; seafloor spreading; temperature anomaly; thermometry; trace element, East Pacific Rise; Hess Deep; Pacific Ocean
Abstract: ▾ We investigate the cooling histories of peridotites and gabbros from localities that expose oceanic lithosphere formed beneath two fast seafloor spreading centers: Hess Deep as recovered from IODP Expedition 345 and ODP Leg 147, and the Oman Ophiolite as sampled by the Oman Drilling Project, ICDP Expedition 5057 (OmanDP). At these locations, relict crust-mantle transition zones are directly sampled, enabling characterization of the thermal history of the crust-mantle transition, and by inference, the depth extent of hydrothermal circulation beneath spreading centers. We measured major and trace element abundances in crustal gabbros and mantle peridotites from Hess Deep and OmanDP, and applied major and trace element-based thermometers. Geospeedometric interpretation of the temperatures suggests similar cooling histories at both locations; cooling rates ranged from 0.02 to 2.6 °C/y from peak temperatures up to 1,350°C. The rates are consistent on either side of the paleo-Moho (i.e., in the crust and mantle). Models for conductive cooling of the lower oceanic crust predict rates more than two orders of magnitude slower at the crust-mantle transition zone, while thermal models that invoke deep and efficient hydrothermal circulation throughout the entire crustal section predict rates consistent with our observations. We infer that hydrothermal cooling extended to or near the petrologic Moho beneath the East Pacific Rise and the OmanDP paleo-spreading center, consistent with the Sheeted Sills model for crustal accretion. Comparison with previously published rates recalculated using the methods we employed suggests the oceanic lower crust is cooled hydrothermally in some places and by conduction at others. © 2021. American Geophysical Union. All Rights Reserved.
2704.
Triprojectacites in the Songliao Basin, Northeast China: Systematics, biostratigraphy and evolution
Cretaceous Research,
135
2022
2703.
Stress State in the Source Region of Mw2.2 Earthquake in a Deep Gold Mine in South Africa Determined from Borehole Cores
Pure and Applied Geophysics,
179
(5)
1679-1700
2022
ISSN: 00334553
Publisher: Birkhauser
Keywords:▾
Deformation; Earthquakes; Faulting; Gold mines; Infill drilling, Deep mine in south africa; Deep-mines; Deformation analysis; Deformation rate analyse; Deformation rate analysis; Diametrical core deformation analyse; Drilling intersecting a seismogenic fault; Earthquake source; Seismogenic faults; Source region; South Africa; Stress in earthquake source region, Boreholes, aftershock; borehole stability; deformation mechanism; drilling; earthquake event; earthquake magnitude; gabbro; gold mine, South Africa
Abstract: ▾ In December 2007, an Mw2.2 earthquake occurred in a gabbroic dike at 3.3 km depth in a deep gold mine in South Africa. The fore- and aftershock activity was analyzed in an effort to understand the preparation and generation processes of earthquakes; these findings have already been published. The present paper focuses on the stress state in the source region of the mainshock. A 90-m-long borehole across the mainshock fault was drilled ~ 1.5 years after the mainshock and logged by an optical televiewer. The fault can be identified by severe damage to the borehole wall at the point where the borehole intersected the aftershock cluster. Except for a 10-m section in the hanging wall of the fault, borehole cores were fully recovered. Borehole breakout (BO) and core disking (CD) were found to occur. Two stress measurement techniques [Deformation Rate Analysis (DRA) and Diametrical Core Deformation Analysis (DCDA)] were applied to the borehole cores. By combining their results with occurrence criteria for BO and CD, the principal stress state in the source region of the mainshock was determined. The principal directions in the hanging wall of the fault were nearly identical to the virgin stress state, while it was significantly disturbed in the footwall. The vertical stresses were 106 MPa and 40 MPa in the hanging wall and footwall, respectively. The significant difference in the vertical stress between the two sides of the fault can be explained by the stress redistribution associated with a nonuniform slip on a nonplanar fault. © 2022, The Author(s).
2702.
Vegetation history of a Mexican Neotropical basin from the late MIS 6 to early MIS 3: The pollen record of Lake Chalco
Quaternary Science Reviews,
297
2022
ISSN: 02773791
Publisher: Elsevier Ltd
Keywords:▾
Forestry; Glacial geology; Lakes; Saline water; Tropics; Vegetation, Basin of mexico; Dry condition; Last glacial; Marine isotopic stages; Me-xico; Millennial-scale variability; Penultimate interglacial; Plant diversity; Pollen analysis; Vegetation dynamics, Climate change, climate change; climate variation; coniferous forest; glacial-interglacial cycle; Last Glacial; late glacial; marine isotope stage; Neotropical Region; palynology; reconstruction; vegetation dynamics; vegetation history, Arctic; Atlantic Ocean; Cariaco Basin; Caribbean Sea; Greenland; Lake Chalco; Mexico [North America]; Valley of Mexico
Abstract: ▾ A new detailed pollen record of the penultimate glacial–interglacial–glacial cycle corresponding to the late marine isotopic stages (MISs) 6–3 (146–35 ka ago) has been obtained from Lake Chalco, in the Basin of Mexico. This record provides an insight into vegetation dynamics and climate variability at the northern limit of the American tropics. The pollen record displays a high temporal resolution with a mean sampling interval of ∼230 years. The changes in plant composition were reconstructed by pollen analysis and differences in plant composition between distinct periods were established. The wettest cold stage, indicated by a combination of diverse open vegetation and mesophytic taxa correlates with the penultimate late glacial MIS 6 (146–130 ka), when Lake Chalco was a deep freshwater lake. The penultimate interglacial MIS 5e (126.5–123.6 ka) shows a dominance of Pinus forests, with tropical taxa suggesting warmer than present conditions; environmental proxies indicate drier conditions and that the lake transitioned into a saline water body. Open communities and Pinus and Quercus forests with mesophytic taxa and, during the stadial periods, MIS 5 d, 5c, and 5 b (125–90 ka), with tropical taxa, characterize the record of interstadials. Pinus-dominated forests characterize the landscape during MIS 5a. MIS 5c to MIS 3 showed lower and variable evenness and palynological richness, along with an increase in fire activity. During MIS 4 and 3, a trend towards drier conditions was also recorded with enhanced carbonate precipitation and proxies indicating saline conditions. Tree-line changes in response to climate change and taxa migration were documented. A comparison with long records from the Greenland ice cores, the marine Cariaco Basin and insolation parameters revealed that the pollen data and the Pinus pollen accumulation rates evidence the response of the vegetation to glacial and interglacial changes and to millennial-scale variability. Wetter conditions were inferred to exist during the Greenland interstadials, while drier conditions persisted during Heinrich events. © 2022 Elsevier Ltd
2701.
Volcanic tremor associated with the Surtsey eruption of 1963–1967
Jökull,
7221-34
2022
2700.
[English]
The remanent magnetisation recorded in the Chesapeake Bay impact crater, Virginia
Volume 2145
,
In Chatthong B., Buranachai C., Kalasuwan P., Rakkapao S., Putson C., Soonthornthum B., Aukkaravittayapun S.,
Editor
Publisher
IOP Publishing Ltd
2022
Division of Physical Science, Faculty of Science, Prince of Songkla University, Songkhla, Hat Yai, 90110, Thailand; Department of Geophysics, Stanford University, Stanford, CA 94305, United States; Department of Earth and Planetary Science, Rutgers University, Piscataway, NJ 08854, United StatesKeywords:▾
Rocks, Chesapeake Bay; High pressure; Impact craters; Impact events; Impact heating; Natural remanent magnetization; Planetary bodies; Recrystallisation; Remanent magnetization; Virginia, Magnetization
2699.
Drilling Overdeepened Alpine Valleys (ICDP-DOVE): Age, extent and environmental impact of Alpine glaciations
EGU General Assembly Conference Abstracts
,
Page EGU22--3165
2022
2698.
How was the Bushveld Complex assembled? A search for cryptic layering in ICDP drillcores from the Main Zone
EGU General Assembly Conference Abstracts
,
Page EGU22--8339
2022
2697.
Intensive peatland wildfires during the Aptian–Albian oceanic anoxic event 1b: Evidence from borehole SK-2 in the Songliao Basin, NE China
Journal of Palaeogeography,
11
(3)
448-467
2022
ISSN: 20953836
Publisher: Elsevier B.V.
Abstract: ▾ The Cretaceous has been considered a “high-fire” world accompanied by widespread by-products of combustion in the rock record. The mid-Cretaceous oceanic anoxic event 1b (OAE1b) is marked by one of the major perturbations in the global carbon cycle characterized by deposition of organic-rich sediments in both marine and terrestrial settings. However, our understanding is still limited on changes in wildfire activity during OAE1b period. Here, we carried out a comprehensive analysis, including organic carbon isotope (δ13Corg), total organic carbon (TOC), coal petrology, trace elements, and pyrolytic polycyclic aromatic hydrocarbons (pyroPAHs), of coal seams of the middle Aptian to early Albian Shahezi Formation from borehole SK-2 in Songliao Basin, Northeast China. Two negative δ13Corg excursions in the Shahezi Formation can be corresponded with the 113/Jacob and Kilian sub-events of OAE1b. Moreover, the intensive peatland wildfires have been identified during the sub-event periods of OAE1b based on the co-occurrence of high abundance of charcoal and pyroPAHs at that time. In addition, Sr/Ba, Sr/Cu and Sr/Rb ratios demonstrate that enhanced peatland wildfires were controlled by dryer climate conditions owing to episodic northward migration of arid zones in East Asia related with rising global temperature during the sub-events of OAE1b. The climate-driven extensive wildfire activity in the mid-latitude terrestrial ecosystems can be a contributing factor for OAE1b through the increased flux of nutrients fuelling primary producers in the lake and marine environments and leading to more speculative anoxia to allow the deposition of organic-rich sediments. Our results provide essential understanding of the importance of wildfires in driving mechanism of oceanic anoxic events (OAEs) in Earth's history. © 2022 The Author(s)
2696.
Study of fluid circulation through the chicxulub crater using Rock-Eval pyrolysis and fluid inclusions
Applied Geochemistry,
137
2022
Abstract: ▾ The aim of the study is to evaluate fluids circulation through the Chicxulub crater, and to determine the composition of hydrothermal fluids after the impact. Rock-Eval pyrolysis and fluid inclusion micro-thermometry analyses were performed. The technique has been routinely used for about fifteen years and has become a standard tool for hydrocarbon exploration. Rock-Eval pyrolysis reveals the distribution of organic and mineral carbon affected by the impact and later affected by hydrothermal activity. All measured inclusions are primary and were found in basement samples only. Both the fluid inclusions data and Rock-Eval pyrolysis show that composition and temperature of the fluids changed as the fluids migrated though crater rocks. An evolution of temperatures occurs (vertical, horizontal, or both), from the surface and from the center of the crater; this spatial evolution is consistent with model of Abramov and Kring, showing a thermal evolution of temperature with depth in the crater as well as its influence on the hydrothermal system. Post-impact fluid circulation modifies the temperature distribution. © 2022 Elsevier Ltd
2695.
Stratigraphic record reveals contrasting roles of overflows and underflows over glacial cycles in a hypersaline lake (Dead Sea)
Earth and Planetary Science Letters,
594
2022
ISSN: 0012821X
Publisher: Elsevier B.V.
Keywords:▾
Climate change; Deposits; Floods; Glacial geology; Orbits; Sediment transport; Stratigraphy, Dead sea; Flash-floods; Flood plumes; Flow process; Geological record; Hypersaline lakes; Sediment density flows; Sediment transport process; Turbidite; Underflows, Lakes, climate change; density; flash flood; geological record; hypersaline environment; lake level; plume; salinity; sediment transport; stratigraphy; turbidite, Dead Sea
Abstract: ▾ In lakes and oceans, links between modern sediment density flow processes and deposits preserved in long-term geological records are poorly understood. Consequently, it is unclear whether, and if so how, long-term climate changes affect the magnitude/frequency of sediment density flows. One approach to answering this question is to analyze a comprehensive geological record that comprises deposits that can be reliably linked to modern sediment flow processes. To address this question, we investigated the unique ICDP Core 5017-1 from the Dead Sea (the largest and deepest hypersaline lake on the Earth) depocenter covering MIS 7-1. Based on an understanding of modern sediment density flow processes in the lake, we link homogeneous muds in the core to overflows (surface flood plumes, ρflow<ρwater), and link graded turbidites and debrites to underflows (ρflow>ρwater). Our dataset reveals (1) overflows are more prominent during interglacials, while underflows are more prominent during glacials; (2) orbital-scale climate changes affected the flow magnitude/frequency via changing salinity and density profile of lake brine, lake-level, and source materials. © 2022 The Author(s)
2694.
Pyroclastic deposition in the Cretaceous Shahezi Formation (Well SK-2) Songliao Basin, China: Implications for tectonics and volcanism
Geological Journal,
57
(6)
2346-2364
2022
ISSN: 00721050
Publisher: John Wiley and Sons Ltd
DOI:10.1002/gj.4414
Keywords:▾
Cretaceous; graben; lithofacies; provenance; pyroclastic deposit; tectonics; transtension; Triassic; volcanism; weathering, China; Songliao Basin
Abstract: ▾ Well SK-2 is located in the Songliao Basin. Core samples from this well indicate that the Early Cretaceous Shahezi Formation has a length of 2,359.01 m and is in direct contact with the basin basement of the Middle Triassic, missing the Huoshiling Formation. This paper is focused on the lowest sequence 1 (S1, at the bottom of the Shahezi Formation, interval of 5,450.72–5,695.00 m, a length of 244.28 m) of the Cretaceous basin fills. It was found that the volcanic components contributed important parts in the sequence of basin fills, and the start of the rifting resulted from the combination of regional extensional tectonics and volcanism. Based on the centimetre-scale description of the continuous core samples, we propose a model to delineate the interaction between tectonics, volcanism, and pyroclastic deposition. The study shows the tectonic-volcanism in the earliest rifting stages and its control on sedimentary filling. These results also have common sense for the initial rifting process of a continental half-graben basin. Sequence 1 of the Shahezi Formation in well SK-2 shows a typical volcanic- sedimentary sequence. During the lowstand stage, the weathering-depositional system was controlled by extension; during the transgressive and highstand stages, the transitional weathering-depositional system and the mixed volcanic and weathering depositional system were controlled by transtension. © 2022 John Wiley & Sons Ltd.
2693.
Resolving impact volatilization and condensation from target rock mixing and hydrothermal overprinting within the Chicxulub impact structure
Geoscience Frontiers,
13
(5)
2022
Abstract: ▾ This work presents isotopic data for the non-traditional isotope systems Fe, Cu, and Zn on a set of Chicxulub impactites and target lithologies with the aim of better documenting the dynamic processes taking place during hypervelocity impact events, as well as those affecting impact structures during the post-impact phase. The focus lies on material from the recent IODP-ICDP Expedition 364 Hole M0077A drill core obtained from the offshore Chicxulub peak ring. Two ejecta blanket samples from the UNAM 5 and 7 cores were used to compare the crater lithologies with those outside of the impact structure. The datasets of bulk Fe, Cu, and Zn isotope ratios are coupled with petrographic observations and bulk major and trace element compositions to disentangle equilibrium isotope fractionation effects from kinetic processes. The observed Fe and Cu isotopic signatures, with δ56/54Fe ranging from −0.95‰ to 0.58‰ and δ65/63Cu from −0.73‰ to 0.14‰, mostly reflect felsic, mafic, and carbonate target lithology mixing and secondary sulfide mineral formation, the latter associated to the extensive and long-lived (>105 years) hydrothermal system within Chicxulub structure. On the other hand, the stable Zn isotope ratios provide evidence for volatility-governed isotopic fractionation. The heavier Zn isotopic compositions observed for the uppermost part of the impactite sequence and a metamorphic clast (δ66/64Zn of up to 0.80‰ and 0.87‰, respectively) relative to most basement lithologies and impact melt rock units indicate partial vaporization of Zn, comparable to what has been observed for Cretaceous-Paleogene boundary layer sediments around the world, as well as for tektites from various strewn fields. In contrast to previous work, our data indicate that an isotopically light Zn reservoir (δ66/64Zn down to −0.49‰), of which the existence has previously been suggested based on mass balance considerations, may reside within the upper impact melt rock (UIM) unit. This observation is restricted to a few UIM samples only and cannot be extended to other target or impact melt rock units. Light isotopic signatures of moderately volatile elements in tektites and microtektites have previously been linked to (back-)condensation under distinct kinetic regimes. Although some of the signatures observed may have been partially overprinted during post-impact processes, our bulk data confirm impact volatilization and condensation of Zn, which may be even more pronounced at the microscale, with variable degrees of mixing between isotopically distinct reservoirs, not only at proximal to distal ejecta sites, but also within the lithologies associated with the Chicxulub impact crater. © 2022 China University of Geosciences (Beijing) and Peking University
2692.
Quaternary environmental changes in central Chukotka (NE Russia) inferred from the Lake El'gygytgyn pollen records
Journal of Quaternary Science,
37
(5)
915-927
2022
ISSN: 02678179
Publisher: John Wiley and Sons Ltd
DOI:10.1002/jqs.3408
Keywords:▾
albedo; environmental change; glacial-interglacial cycle; ice; Milankovitch cycle; Pleistocene; pollen; snow; vegetation, Chukchi; Elgygytgyn Lake; Russian Federation
Abstract: ▾ The 3.6-Myr sedimentary record of Lake El'gygytgyn is crucial for understanding the response of the sensitive ecosystems in the Arctic to Quaternary climate variations at orbital timescales. In this study, we synthesize previously published pollen records and biome reconstructions and perform pollen diversity analysis of the deep-drilling core ICDP 5011-1 from Lake El'gygytgyn for periods during the Early Pleistocene (MIS 82 – MIS 79), Early–Middle Pleistocene (MIS 31 – MIS 18) and late Middle Pleistocene (MIS 7e – MIS 6f). The results indicate that the predominance of herb tundra in the regional vegetation was most characteristic during glacials/stadials. Interglacials, in contrast, can be distinguished by the expansion of shrub communities mainly composed of birch, alder and willow. The expansion of forest biomes in the region was influenced by peaks in obliquity values, which led to increases in daylight length, which was essential for plant growth in high latitudes. An apparent long-term decreasing trend in the tree and shrub population, accompanied by a reduction in floristic richness, was induced by stepwise cooling and drying since the Mid-Pleistocene Transition (MPT), which is linked to the modulation of extended global ice volume during the MPT via strong snow- and ice-albedo feedback effects. © 2022 John Wiley & Sons, Ltd.
2691.
Reconstructing the Environmental Context of Human Origins in Eastern Africa Through Scientific Drilling
Annual Review of Earth and Planetary Sciences,
50451 – 476
2022
2690.
Reconstructing the Environmental Context of Human Origins in Eastern Africa Through Scientific Drilling
Annual Review of Earth and Planetary Sciences,
50451 – 476
2022
ISSN: 00846597
Publisher: Annual Reviews Inc.
Keywords:▾
Africa; Core drilling; Drills; Infill drilling; Sedimentary rocks; Stratigraphy; Continental scientific drillings; Drill core; East African Rift; Eastern Africa; Environmental contexts; High resolution; Hominins; Human evolution; Late Neogene; Paleoclimates; environmental change; environmental history; human evolution; Neogene; paleoclimate; Pleistocene; Lakes
Abstract: ▾ Paleoanthropologists have long speculated about the role of environmental change in shaping human evolution in Africa. In recent years, drill cores of late Neogene lacustrine sedimentary rocks have yielded valuable high-resolution records of climatic and ecosystem change. Eastern African Rift sediments (primarily lake beds) provide an extraordinary range of data in close proximity to important fossil hominin and archaeological sites, allowing critical study of hypotheses that connect environmental history and hominin evolution. We review recent drill-core studies spanning the Plio-Pleistocene boundary (an interval of hominin diversification, including the earliest members of our genus Homo and the oldest stone tools), and the Mid-Upper Pleistocene (spanning the origin of Homo sapiens in Africa and our early technological and dispersal history). Proposed drilling of Africa's oldest lakes promises to extend such records back to the late Miocene. squf High-resolution paleoenvironmental records are critical for understanding external drivers of human evolution. squf African lake basin drill cores play a critical role in enhancing hominin paleoenvironmental records given their continuity and proximity to key paleoanthropological sites. squf The oldest African lakes have the potential to reveal a comprehensive paleoenvironmental context for the entire late Neogene history of hominin evolution. © 2022 by Annual Reviews. All rights reserved.
2689.
Reduced plate motion controlled timing of Early Jurassic Karoo-Ferrar
large igneous province volcanism
SCIENCE ADVANCES,
8
2022
2688.
Research and application of high−temperature drilling fluid designed for the continental scientific drilling project of Songliao Basin, China
Energy Sources, Part A: Recovery, Utilization and Environmental Effects,
44
(1)
2075-2087
2022
ISSN: 15567036
Publisher: Taylor and Francis Ltd.
Keywords:▾
Additives; Bentonite; Drilling fluids; Infill drilling; Thermodynamic stability, Bottom hole temperatures; Continental scientific drillings; Drilling fluid systems; High temperature resistance; High temperature stability; Research and application; Rheological behaviour; Songliao basin, Core drilling
Abstract: ▾ Well Songke−2 is the main hole of the Continental Scientific Drilling Project of Songliao Basin, China, and its bottom hole temperature is estimated to exceed 240°C in the fourth spud at the well depth of 5800 m. To ensure that the drilling fluid could meet the demand of high temperature resistance, different components, including clay, filtration reducers and anti−collapse additives, of the high–temperature drilling fluid system were optimized through thermal stability tests. Comprehensive test results suggested that the optimal bentonite content to be 4% (w/v). Compared with other materials of the same type, polymer filtration reducers SO−1 and HLW−1, as well as sulfonation additive LOCKSEAL were demonstrated to have stronger resistance to high temperature. The proposed high temperature drilling fluid formula exhibited good thermal stability, rheological behaviour, anti−contamination capacity and shale inhibition property. Finally, a great success of the formula was practically obtained in the field application during the following−up core drilling project. © 2022 Taylor & Francis Group, LLC.
2687.
Research progress of absorption and attenuation mechanism and petrophysical theory for gas hydrate reservoir [天然气水合物储层吸收衰减机制及岩石物理理论研究进展]
Shiyou Diqiu Wuli Kantan/Oil Geophysical Prospecting,
57
(4)
992-1008
2022
ISSN: 10007210
Publisher: Science Press
Keywords:▾
Gas hydrates; Gases; Hydration; Microstructure; Petroleum prospecting; Petrophysics; Seismology, Attenuation characteristics; Bottom simulating reflection; Exploration technologies; Gas hydrate reservoir; Hydrate saturation; Petrophysical; Petrophysics; Quantitative interpretation; Reflection characteristics; Seismic attenuation, Seismic waves
Abstract: ▾ The bottom simulating reflection (BSR) characteristics of reflected seismic waves are an important sign of gas hydrate. Although they can indicate the bottom of hydrate, they can hardly be used for quantitative interpretation of hydrate content. The rapid development of the gas hydrate exploration technology in recent years results in an understanding that the "blank" zone of seismic amplitude above BSR, directly related to the absorption and attenuation of seismic waves, can be used as an indicator of gas hydrate distribution and quantification. This paper reviews the seismic wave absorption and attenuation characteristics of various hydrate exploration areas around the world (the Mallik permafrost area in Canada, the Nankai Trough in Japan, the Makran accretionary wedge in the Arabian Sea, the Gulf of Mexico, and the Shenhu area in the South China Sea) and artificial hydrate-bearing rock samples. The results show that for different hydrate exploration areas, hydrate-bearing samples, and data used, seismic waves show different attenuation characteristics. Then, the possible attenuation mechanisms and related petrophysical theories are summarized for hydrate reservoirs, mainly including global flow attenuation (the Leclaire model), squirt flow (the improved Leclaire model, the hydrate effective grain (HEG) model for submicron hydrate particle squirt, or the hydrate-bearing effective sediment (HBES) model for micron flow squirt), skeleton friction attenuation (the improved Leclaire model). At present, the main problem is that although the hydrate-bearing strata in many areas demonstrate obvious absorption and attenuation characteristics, the relationships of absorption and attenuation variation with hydrate saturation remain unknown due to the varied hydrate formation conditions and geological environments and different occurrence states of hydrate in sediments of different areas. In addition, the frequency band ranges of the current measured observation data and those petrophysical experiments test are limited, so the characteristics of attenuation variation with frequency are not fully reflected. Therefore, petrophysical experimental studies need to be further conducted, and available data from actual exploration areas and the making and experimental measurement results of artificial cores shall be well utilized, thereby studying the additional effect of the microstructure of the hydrate reservoir on the attenuation mechanism in depth. After the reasons of seismic wave attenuation in hydrate reservoirs are clarified, a quantitative seismic interpretation method for hydrate saturation can be developed. © 2022, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.
2686.
Revisiting the Milankovitch Theory from the Perspective of the 405 ka Long Eccentricity Cycle; [从40万年长偏心率周期看米兰科维奇理论]
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences,
47
(10)
3543 – 3568
2022
2685.
Spectroscopic study of terrestrial analogues to support rover missions to Mars – A Raman-centred review
Analytica Chimica Acta,
1209
2022