All ICDP Publications with Abstracts
From parent-sysfolder "Publications" + 2 folder-levels deep
2734.
NEW APPROACH TO SEPARATE AND DATE SMALL SPORES AND POLLEN FROM LAKE SEDIMENTS IN SEMI-ARID CLIMATES
Radiocarbon,
64
(5)
1191 – 1207
2022
2733.
Pleistocene climate variability in eastern Africa influenced hominin evolution
Nature Geoscience,
15
(10)
805 – 811
2022
2732.
New insights into the formation and emplacement of impact melt rocks within the Chicxulub impact structure, following the 2016 IODP-ICDP Expedition 364
Bulletin of the Geological Society of America,
134
(1-2)
293-315
2022
DOI:10.1130/B35795.1
Abstract: ▾ This study presents petrographic and geochemical characterization of 46 pre-impact rocks and 32 impactites containing and/ or representing impact melt rock from the peak ring of the Chicxulub impact structure (Yucatán, Mexico). The aims were both to investigate the components that potentially contributed to the impact melt (i.e., the preimpact lithologies) and to better elucidate impact melt rock emplacement at Chicxulub. The impactites presented here are subdivided into two sample groups: the lower impact melt rock-bearing unit, which intrudes the peak ring at different intervals, and the upper impact melt rock unit, which overlies the peak ring. The geochemical characterization of five identified pre-impact lithologies (i.e., granitoid, dolerite, dacite, felsite, and limestone) was able to constrain the bulk geochemical composition of both impactite units. These pre-impact lithologies thus likely represent the main constituent lithologies that were involved in the formation of impact melt rock. In general, the composition of both impactite units can be explained by mixing of the primarily felsic and mafic lithologies, but with varying degrees of carbonate dilution. It is assumed that the two units were initially part of the same impact-produced melt, but discrete processes separated them during crater formation. The lower impact melt rock-bearing unit is interpreted to represent impact melt rock injected into the crystalline basement during the compression/excavation stage of cratering. These impact melt rock layers acted as delamination surfaces within the crystalline basement, accommodating its displacement during peak ring formation. This movement strongly comminuted the impact melt rock layers present in the peak ring structure. The composition of the upper impact melt rock unit was contingent on the entrainment of carbonate components and is interpreted to have stayed at the surface during crater development. Its formation was not finalized until the modification stage, when carbonate material would have reentered the crater. © 2022 Geological Society of Amer. All Rights Reserved.
2731.
Long-term preservation of Hadean protocrust in Earth's mantle
Proceedings of the National Academy of Sciences of the United States of America,
119
(18)
2022
2730.
Near-surface three-dimensional multicomponent source and receiver S-wave survey in the Tannwald Basin, Germany: Acquisition and data processing
Near Surface Geophysics,
20
(4)
331--348
2022
2729.
Logging evaluation of deep lacustrine shale reservoir in Songliao Basin: a case study of international continental scientific drilling; [松辽盆地深层陆相页岩储层测井评价：以国际大陆科学钻探为例]
Zhongnan Daxue Xuebao (Ziran Kexue Ban)/Journal of Central South University (Science and Technology),
53
(9)
3271 – 3286
2022
ISSN: 16727207
Publisher: Central South University of Technology
Keywords:▾
Brittleness; Energy resources; Fracture mechanics; Gas permeability; Gases; Low permeability reservoirs; Oil bearing formations; Organic carbon; Petroleum prospecting; Petroleum reservoir evaluation; Petrophysics; Plasticity; Shale gas; Well logging; Bearing characteristic; Case-studies; Continental scientific drillings; Gas content; Lacustrine shale; Logging evaluation; Shahezi formations; Shale gas reservoirs; SK-2 well; Songliao basin; Porosity
Abstract: ▾ With large cumulative thickness and obvious gas-bearing characteristics, the Songliao Continental Scientific Drilling SK-2 Well has many anomalous gas logging intervals in deep Shahezi formation, revealing that the deep lacustrine shale strata has good prospects for exploration in the Songliao Basin. Using conventional and special logging methods, combined with the core test data, shale reservoir evaluation was carried out in 3 700 − 4 500 m interval of Shahezi formation,logging curve overlay and intersection graph methods were used to identify shale gas reservoirs, the parameters of total organic carbon mass fraction(w(TOC)), porosity, permeability, brittleness and total gas content of shale reservoirs were analyzed quantitatively and interpretation models and calculation methods were established. The results show that the deep lacustrine Shahezi shale gas reservoirs show the characteristics of high natural gamma, high resistivity, low uranium(U), low sonic differential time, low density and low compensation neutrons. The w(TOC) is high in part intervals of 3 700−4 500 m, and the average w(TOC) of some intervals is above 2%. The porosity is between 0.28% − 8.45%, the permeability is (0.002 − 0.509) ×10−3 μm2, the brittleness index is in the range of 19.86%−67.87%, and the total gas content is 1.79−2.57 m3/t. Generally, the deep lacustrine shale reservoirs are characterized by low porosity and low permeability in Songliao Basin and there are many gas-bearing intervals. The 3 722−3 762 m, 3 820−3 860 m, 4 100−4 150 m and 4 400−4 460 m intervals are classified as Type I gas-bearing reservoirs, and the 3 890−3 940 m, 4 220−4 280 m and 4 320−4 360 m intervals are Type II gas-bearing reservoirs, which have the potential for shale gas resource development. © 2022 Central South University of Technology. All rights reserved.
2728.
Progressive veining during peridotite carbonation: insights from listvenites in Hole BT1B, Samail ophiolite (Oman)
Solid Earth,
13
(8)
1191-1218
2022
ISSN: 18699510
Publisher: Copernicus GmbH
Keywords:▾
Carbon dioxide; Flow of fluids; Iron oxides; Magnesia; Magnesite; Mineralogy; Quartz; Rocks; Serpentine; Textures, Carbonate rock; Cross-cutting; Drilling projects; Fe oxide; Fluid fluxes; Quartz + carbonates; Serpentinite; Serpentinized peridotites; Solid volumes; Vein formation, Carbonation, mineralization; ophiolite; peridotite; quartz; serpentinite; serpentinization; zoning, Oman
Abstract: ▾ The reaction of serpentinized peridotite with CO2-bearing fluids to form listvenite (quartz-carbonate rock) requires massive fluid flux and significant permeability despite an increase in solid volume. Listvenite and serpentinite samples from Hole BT1B of the Oman Drilling Project help to understand mechanisms and feedbacks during vein formation in this process. Samples analyzed in this study contain abundant magnesite veins in closely spaced, parallel sets and younger quartz-rich veins. Cross-cutting relationships suggest that antitaxial, zoned magnesite veins with elongated grains growing from a median zone towards the wall rock are among the earliest structures to form during carbonation of serpentinite. Their bisymmetric chemical zoning of variable Ca and Fe contents, a systematic distribution of SiO2 and Fe-oxide inclusions in these zones, and cross-cutting relations with Fe oxides and Cr spinel indicate that they record progress of reaction fronts during replacement of serpentine by carbonate in addition to dilatant vein growth. Euhedral terminations and growth textures of magnesite vein fill, together with local dolomite precipitation and voids along the vein-wall rock interface, suggest that these veins acted as preferred fluid pathways allowing infiltration of CO2-rich fluids necessary for carbonation to progress. Fracturing and fluid flow were probably further enabled by external tectonic stress, as indicated by closely spaced sets of subparallel carbonate veins. Despite widespread subsequent quartz mineralization in the rock matrix and veins, which most likely caused a reduction in the permeability network, carbonation proceeded to completion within listvenite horizons. © 2022 Manuel D. Menzel et al.
2727.
Large-scale, flat-lying mafic intrusions in the Baltican crust and their influence on basement deformation during the Caledonian orogeny
GSA Bulletin
2022
ISSN: 0016-7606DOI:10.1130/B36202.1
Abstract: ▾ The Fennoscandian Shield in central Sweden displays a complex structural and compositional architecture that is mainly related to the Proterozoic history of the Baltica paleocontinent. In its western parts, the Precambrian basement is covered by the allochthonous rocks of the Caledonide orogen, and direct information about the underlying crust is restricted to a few unevenly distributed basement windows in western Sweden and Norway. In this study, we use preliminary results from the second borehole of the Collisional Orogeny in the Scandinavian Caledonides project (COSC-2), new gravity data, forward gravity, and magnetic modeling and interpretation of seismic reflection profiles to assess the 3-D architecture of the basement. Our results reveal a wide (∼100 km) and dense network of mainly flat-lying and saucer-shaped dolerites intruding the volcanic and granitic upper crustal rocks of the Transscandinavian Igneous Belt. Similar intrusion geometries related to 1.2 Ga dolerites can be recognized in the Fennoscandian Shield. We discuss that the formation of these sill complexes occurred in a lithologically and structurally heterogeneous crust during transtension, which is in disagreement with the current understanding of sill emplacement that involves crustal shortening, layering, or anisotropy of the host rock. Our seismic interpretation and the structural observations from the COSC-2 drilling show that part of the Caledonian-related basement deformation was localized along the margins of the dolerite sheets. We propose that the dolerite intrusion geometry, akin to a flat-ramp geometry, guided the basement deformation during the Caledonian orogeny.
2726.
Late Quaternary hydroclimate of the Levant: The leaf wax record from the Dead Sea
Quaternary Science Reviews,
289
2022
ISSN: 02773791
Publisher: Elsevier Ltd
Keywords:▾
Atmospheric thermodynamics; Climate change; Expansion; Gas emissions; Greenhouse gases; Lithology; Principal component analysis; Rain; Storms, Dead sea; Deep drilling; Drilling projects; Isotope of precipitation; Last interglacial; Leaf wax; Levant climate; Paleoclimate records; Pollen; δD, Isotopes, annual cycle; climate change; drought; greenhouse gas; historical record; hydrological cycle; hydrometeorology; Last Interglacial; paleoclimate; pollen; precipitation (chemistry); Quaternary; speleothem; wax, Arabian Peninsula; Dead Sea; Israel; Jerusalem [Israel]; Levant; Mediterranean Region; Soreq Cave
Abstract: ▾ The eastern Mediterranean is projected to experience increases in drought and extreme rainfall in response to rising greenhouse gas emissions. Paleoclimate records from this region are crucial to further constrain the response of the water cycle to a globally warmer climate. Of these, the Dead Sea lacustrine record, collected by the Dead Sea Deep Drilling Project (DSDDP), provides a detailed history of climate change over the past 200,000 years and documents large-magnitude changes in regional water balance. Here, we analyze leaf wax isotopes (δDwax, δ13Cwax) on DSDDP 5017-1 and compare results to other proxies analyzed on the same core. The δDwax record closely resembles the speleothem δ18O record from nearby Soreq Cave, suggesting that both record a regionally coherent signature of glacial-interglacial cycles and the interplay between winter season rainfall and large-scale expansion and contraction of the Afro-Asian monsoon system. Principal components analysis of the pollen and core lithology shows that the first-order driver of variability in the Dead Sea paleoclimate record is global temperature, which controls effective moisture by modulating atmospheric evaporative demand. Leaf wax, pollen, and core lithology all suggest radical changes in the annual cycle of precipitation during the peak of the Last Interglacial. We hypothesize that the Dead Sea Basin experienced a dual-rainfall regime during this time, with intensified winter storms and a summer monsoon season. While these changes were driven by the Earth's precessional cycle, model simulations suggest a similar expansion of the African monsoon domain into the Arabian Peninsula under elevated CO2 levels. The Last Interglacial climate of the DSB provides a glimpse of what future climate in the southeastern Mediterranean region could look like. © 2022 Elsevier Ltd
2725.
Life before impact in the Chicxulub area: unique marine ichnological signatures preserved in crater suevite
Scientific Reports,
12
(1)
2022
Abstract: ▾ To fully assess the resilience and recovery of life in response to the Cretaceous-Paleogene (K-Pg) boundary mass extinction ~ 66 million years ago, it is paramount to understand biodiversity prior to the Chicxulub impact event. The peak ring of the Chicxulub impact structure offshore the Yucatán Peninsula (México) was recently drilled and extracted a ~ 100 m thick impact-generated, melt-bearing, polymict breccia (crater suevite), which preserved carbonate clasts with common biogenic structures. We pieced this information to reproduce for the first time the macrobenthic tracemaker community and marine paleoenvironment prior to a large impact event at the crater area by combining paleoichnology with micropaleontology. A variable macrobenthic tracemaker community was present prior to the impact (Cenomanian–Maastrichtian), which included soft bodied organisms such as annelids, crustaceans and bivalves, mainly colonizing softgrounds in marine oxygenated, nutrient rich, conditions. Trace fossil assemblage from these upper Cretaceous core lithologies, with dominant Planolites and frequent Chondrites, corresponds well with that in the overlying post-impact Paleogene sediments. This reveals that the K-Pg impact event had no significant effects (i.e., extinction) on the composition of the macroinvertebrate tracemaker community in the Chicxulub region. © 2022, The Author(s).
2724.
Linking exhumation, paleo-relief, and rift formation to magmatic processes in the western Snake River Plain, Idaho, using apatite (U-Th)/He thermochronology
Geosphere,
18
(2)
885-909
2022
ISSN: 1553040X
Publisher: Geological Society of America
Keywords:▾
Apatite; Basalt; Cooling; Tectonics; Topography, Idaho Batholith; Magmatic intrusions; Magmatic process; Miocene; Plutons; Rapid cooling; Rift basin; Snake river plains; Thermochronometry; U-Th/He thermochronology, Rivers, apatite; bedrock; exhumation; granitoid; magmatism; pluton; relief; rift zone; thermochronology; uranium series dating, Idaho; Snake River Plain; United States
Abstract: ▾ The western Snake River Plain (WSRP) in southwest Idaho has been characterized as an intracontinental rift basin but differs markedly in topography and style from other Cordilleran extensional structures and structurally from the down-warped lava plain of the eastern Snake River Plain. To investigate mechanisms driving extension and topographic evolution, we sampled granitoid bedrock from Cretaceous and Eocene-aged plutons from the mountainous flanks of the WSRP to detail their exhumation history with apatite (U-Th)/He (AHe) thermochronometry. AHe cooling dates from seventeen samples range from 7.9 ± 1.4 Ma to 55 ± 10 Ma. Most cooling dates from Cretaceous plutons adjacent to the WSRP are Eocene, while Eocene intrusions from within the Middle Fork Boise River canyon ~35 km NE of the WSRP yield Miocene cooling dates. The AHe dates provide evidence of exhumation of the Idaho batholith during the Eocene, supporting a high relief landscape at that time, followed by decreasing relief. The Miocene AHe dates show rapid cooling along the Middle Fork Boise River that we take to indicate focused river incision due to base level fall in the WSRP. Eocene AHe dates limit magnitudes of exhumation and extension on the flanks of the WSRP during Miocene rift formation. This suggests extension was accommodated by magmatic intrusions and intrabasin faults rather than basin-bounding faults. We favor a model where WSRP extension was related to Columbia River Flood Basalt eruption and enhanced by later eruption of the Bruneau-Jarbidge and Twin Falls volcanic fields, explaining the apparent difference with other Cordilleran extensional structures. © 2022. The Authors. All Rights Reserved.
2723.
Listvenite formation during mass transfer into the leading edge of the mantle wedge: Initial results from Oman Drilling Project Hole BT1B
Journal of Geophysical Research: Solid Earth,
127
(2)
e2021JB022352
2022
ISSN: 21699313
Publisher: Wiley Online Library
Keywords:▾
carbon cycle; drilling; ductile deformation; mantle; mass transfer; ophiolite; subduction zone; ultramafic rock, Oman
Abstract: ▾ This paper provides an overview of research on core from Oman Drilling Project Hole BT1B and the surrounding area, plus new data and calculations, constraining processes in the Tethyan subduction zone beneath the Samail ophiolite. The area is underlain by gently dipping, broadly folded layers of allochthonous Hawasina pelagic sediments, the metamorphic sole of the Samail ophiolite, and Banded Unit peridotites at the base of the Samail mantle section. Despite reactivation of some faults during uplift of the Jebel Akdar and Saih Hatat domes, the area preserves the tectonic “stratigraphy” of the Cretaceous subduction zone. Gently dipping listvenite bands, parallel to peridotite banding and to contacts between the peridotite and the metamorphic sole, replace peridotite at and near the basal thrust. Listvenites formed at less than 200°C and (poorly constrained) depths of 25–40 km by reaction with CO2-rich, aqueous fluids migrating from greater depths, derived from devolatilization of subducting sediments analogous to clastic sediments in the Hawasina Formation, at 400°–500°. Such processes could form important reservoirs for subducted CO2. Listvenite formation was accompanied by ductile deformation of serpentinites and listvenites—perhaps facilitated by fluid-rock reaction—in a process that could lead to aseismic subduction in some regions. Addition of H2O and CO2 to the mantle wedge, forming serpentinites and listvenites, caused large increases in the solid mass and volume of the rocks. This may have been accommodated by fractures formed as a result of volume changes, mainly at a serpentinization front. © 2022. American Geophysical Union. All Rights Reserved.
2722.
Logging evaluation of deep multi-type unconventional gas reservoirs in the Songliao basin, northeast China: Implications from continental scientific drilling
Geoscience Frontiers,
13
(6)
2022
ISSN: 16749871
Publisher: Elsevier B.V.
Keywords:▾
China; Songliao Basin; drilling; hydrocarbon exploration; hydrocarbon reservoir; logging (geophysics); natural gas; reservoir characterization
Abstract: ▾ Multi-type unconventional gas-bearing reservoirs with different lithologies and gas accumulation potential occur in the deep part of the Songliao basin. However, the reservoirs are non-homogeneous, the gas components differ substantially, and not all types of gas-bearing reservoirs have been identified or evaluated. The International Continental Scientific Drilling Program (ICDP) is used as an example to conduct qualitative and quantitative evaluations of deep multi-type unconventional gas-bearing reservoirs using conventional and specialized logging data. The core test data are used to determine the physical properties. The porosity and permeability are compared and analyzed using different methods and models. The results show that the reservoirs have low to ultra-low porosity and ultra-low permeability. Based on the comparison of the rock mechanical parameters and mineral composition, brittleness evaluation parameters are proposed for different types of deep reservoirs in the study region. The mineral brittleness index is highly consistent with the brittleness index based on rock mechanics. An identification method for deep multi-type gas-bearing reservoir and a classification approach for different gas properties are established based on the logging response and parameter interpretation. The methane gas reservoirs have low density (DEN) and low compensated neutron logging (CNL) values and high acoustic (AC) time difference and high resistivity (RT) values. The CO2 gas reservoirs have lower RT values and higher CNL values than the hydrocarbon gas reservoirs. The comprehensive analysis of deep gas source rock conditions and of the source-reservoir relationship provides insights for the evaluation of deep multi-type unconventional gas reservoirs. The discovery of high hydrogen content is of significant importance for developing new areas for deep natural gas exploration. © 2022 China University of Geosciences (Beijing) and Peking University
2721.
Multisegment ruptures and Vp/Vs variations during the 2020-2021 seismic crisis in western Corinth Gulf, Greece
Geophysical Journal International,
230
(1)
334 – 348
2022
ISSN: 0956540X
Publisher: Oxford University Press
Keywords:▾
Greece; Gulf of Corinth; Ionian Sea; Mediterranean Sea; Faulting; Offshore oil well production; Principal component analysis; Continental tectonics: Extensional; Fault strain; Fracture strain; Fracture, fault, and high strain deformation zone; High strain deformation zones; Multi-segment; Offshores; Seismic activity; Seismicity and tectonics; Small-magnitude earthquakes; deformation; extensional tectonics; fault; fracture zone; P-wave; rupture; S-wave; seismicity; strain analysis; Earthquakes
Abstract: ▾ On 2020 December 23, a seismic crisis initiated in the western Corinth Gulf offshore Marathias, lasted several months, and generated thousands of small magnitude earthquakes. The Gulf of Corinth is well known for earthquake swarm occurrence and short-lived burst-like earthquake sequences, mostly triggered by crustal fluids. Here, we perform a detailed seismic analysis aiming to identifying earthquake clusters within the seismic crisis and define their spatial and temporal characteristics. Thanks to the dense seismic station coverage in the area, operated by the Hellenic Unified Seismological Network and Corinth Rift Laboratory, we relocate shallow seismicity and compile a high-resolution earthquake catalogue containing ∼1400 earthquakes spanning the first two months of the seismic crisis. We identify 19 earthquake clusters by applying spatio-temporal criteria and define the geometry (strike and dip) using principal component analysis for 11 of them. Our results are consistent with moment tensor solutions computed for the largest earthquake in each cluster. A striking feature of the seismic activity is the west-towards-east migration with a notable increase in Vp/Vs values for each cluster and a slight increase of the dip angle for the identified fault segments. Furthermore, we find that each cluster contains several burst-like, short interevent time, repeating earthquakes, which could be related to aseismic slip or fluid migration. Overall, we show that the 2020-2021 seismic crisis consists of earthquake clusters that bifurcate between swarm-like and main shock-aftershock-like sequences and ruptured both north- and south-dipping high-angle fault segments. The 2020-2021 seismic activity is located between 5 to 8 km, shallower than the low angle north-dipping (∼10°) seismic zone which hosts long-lived repeating sequences at ∼9-10 km depth. This study supports a hypothesis that the low-angle north-dipping seismicity defines the brittle-ductile transition in the western Corinth Gulf, with seismic bursts occurring at shallower depths in the crust. © 2022 The Author(s) 2022. Published by Oxford University Press on behalf of The Royal Astronomical Society.
2720.
Magnetostratigraphy of the Upper Cretaceous Nenjiang Formation in the Songliao Basin, northeast China: Implications for age constraints on terminating the Cretaceous Normal Superchron
Cretaceous Research,
135
2022
ISSN: 01956671
Publisher: Academic Press
Keywords:▾
accuracy assessment; age determination; borehole geophysics; chronostratigraphy; Cretaceous; error correction; geochronology; lithostratigraphy; magnetic susceptibility; magnetostratigraphy; uranium; uranium-lead dating, China; Songliao Basin
Abstract: ▾ We developed an integrated chronology for the non-marine Upper Cretaceous Nenjiang Formation based on high-resolution magnetostratigraphic results and previously published secondary ion mass spectrometry (SIMS) U–Pb zircon analyses of the eastern borehole of the Cretaceous Continental Scientific Drilling (CCSD-SK-II) borehole and two outcrop sections located in different structural provinces of the Songliao Basin, China. Detailed rock magnetic results demonstrated that pseudo-single-domain magnetite and single-domain greigite coexisted in the lacustrine black shales of the Nenjiang Formation, with the latter dominating remanence carriers. The reliable primary remanent magnetizations were isolated, which passed a class A positive reversal test and positive bootstrap reversal test, after correction for inclination shallowing, yielding a high-quality paleopole of 79.6°N/208.4°E, A95 = 2.3°. The borehole sequence and outcrop sections were stratigraphically correlated by combining lithostratigraphy, biostratigraphy, and SIMS U–Pb zircon geochronology. The correlation of the recognized magnetic polarity sequences to the geomagnetic polarity timescale suggests that the Nenjiang Formation from the CCSD-SK-II borehole sequence and the two outcrop sections span from very late chron C34n to very early chron C33r. Furthermore, the age of the Cretaceous Normal Superchron (CNS) termination can be constrained to 82.7 ± 0.6 Ma based on magnetostratigraphy, radiometric dating, and the perfect/typical averaged sediment accumulation rate for Member 1 of the Nenjiang Formation of the borehole sequence. The estimated age obtained in this study accurately represents the age at CNS termination. © 2022 Elsevier Ltd
2719.
Major sulfur cycle perturbations in the Panthalassic Ocean across the
Pliensbachian-Toarcian boundary and the Toarcian Oceanic Anoxic Event
GLOBAL AND PLANETARY CHANGE,
215
2022
Keywords:▾
Early Toarcian; Panthalassic Ocean; Sulfur cycle; Pyrite sulfur isotope;
Local sedimentary environment
2718.
Measurements of the inclination of the SE-03 Borehole on Surtsey Volcano
Surtsey research,
15121-126
2022
2717.
Microbial biosignature preservation in carbonated serpentine from the Samail Ophiolite, Oman
Communications Earth and Environment,
3
(1)
2022
2716.
Mid-latitude precipitation in East Asia influenced by a fluctuating greenhouse climate during the latest Cretaceous through the earliest Paleogene
Global and Planetary Change,
216
2022
ISSN: 09218181
Publisher: Elsevier B.V.
Keywords:▾
China; Songliao Basin; Carbon dioxide; Greenhouses; Cretaceous; East Asia; Greenhouse climates; Late cretaceous; Mean annual precipitation; Midlatitudes; Palaeosols; Paleogene; Songliao basin; Time records; air mass; carbon dioxide; concentration (composition); cooling; Cretaceous; hydrological cycle; low pressure system; Northern Hemisphere; paleosol; precipitation (climatology); proxy climate record; warming; Weathering
Abstract: ▾ Deep-time records from greenhouse climate periods (e.g., the Late Cretaceous) provide a reference point for understanding how high atmospheric CO2 concentrations influence precipitation in the mid-latitude Northern Hemisphere (e.g., East Asia). In this study, we quantitatively reconstruct mean annual precipitation (MAP) in East Asia during the latest Cretaceous through the earliest Paleogene (~76–65.5 Ma), based on a well-studied paleosol sequence from the Sifangtai and Mingshui Formations from the SK-1n scientific borehole in the Songliao Basin, northeastern China. We use several proxies, including sedimentary-based observational proxies (e.g., depth to the calcic horizon, DTC) and elemental geochemistry proxies in the paleosol B horizon (e.g., the chemical index of alteration minus potassium, CIA-K; the calcium‑magnesium weathering index, CALMAG), which show the consistency with weathering proxies and previously published isotopic records. Changes in the MAP are associated with warming and cooling events. In the warciaming period (e.g., at ~69.5–68.5 Ma), an increase in the land-sea thermal contrast led to an expanded, enhanced, poleward-shifted thermal low-pressure system over the East Asian continent, which triggered an enhanced hydrological cycle and increasing MAP in the Songliao Basin. During the cooling period (e.g., at ~72.5–69.5 Ma and ~68.5–66.5 Ma), weakened East Asian monsoon and strengthened equatorward-shifted westerlies allowed for colder and arid air masses to encroach upon the Songliao Basin, which led to decreased MAP. Changes in MAP across the K-Pg boundary coincide with climate fluctuations and catastrophic geological events. Furthermore, our work compares three warming intervals in deep-time (middle Maastrichtian, late Maastrichtian and earliest Paleogene) with Shared Socio-economic Pathway scenarios used by the IPCC for the end of the 21st century, and indicates MAP increases in East Asia with ongoing anthropogenic CO2 emissions. © 2022 Elsevier B.V.
2715.
Molecular hydrogen from organic sources in the deep Songliao Basin, P.R. China
International Journal of Hydrogen Energy,
47
(38)
16750-16774
2022
ISSN: 03603199
Publisher: Elsevier Ltd
Keywords:▾
Hydrogen storage; Kinetic theory; Molecular physics, Aromatization and cracking; Hydrogen trapping; Hydrogen trapping and storage; Kinetic models; Molecular hydrogen; Natural maturity series; Natural organic hydrogen; Natural organics; Organic sources; Songliao basin, Mass spectrometry
Abstract: ▾ Free hydrogen detected in the Songke-2 well (Songliao Basin, China) has a strong crustal contribution. Here we evaluate whether the source could be the organic matter in Lower Cretaceous coals and shales, and extend our findings regionally. We could establish the rapid growth of aromatic ring systems, forming hydrogen, methane and pyrobitumen, using high resolution mass spectrometry. Molecular hydrogen is generated after late hydrocarbon gas generation is complete, concluding at Rr = 5.0%. The kinetic parameters of molecular hydrogen formation were constructed by subtracting the hydrogen associated with hydrocarbon formation from the total hydrogen, as measured by extensive open system pyrolysis experiments. This new insight was achieved using a CH4–H2 stoichiometric balance. Generalised calculations indicate that the yield per unit rock volume closely resembles that of economic shale gas in the Barnett Shale, though storage in organic matrices is unlikely in this depositional setting. While the prolific generation of hydrogen from organic sources appears to be a reality in the Songliao basin, the free H2 in the Songke-2 mudstream coming from this source must most likely have migrated into the basement rocks mainly from lateral equivalents of the Shahezi rather than from the drilled section itself. © 2022 Hydrogen Energy Publications LLC
2714.
Present situation and prospect of drilling and completion of 10000 meter scientific ultra deep wells (in Chinese with English abstract);[万米科学超深井钻完井现状与展望]
Science & Technology Review,
40
(13)
27-35
2022
2713.
Subaqueous event deposits response to regional neotectonics: Case studies of the Dead Sea Basin and the Qaidam Basin
Quaternary Sciences,
42
(3)
617-636
2022
ISSN: 10017410
Publisher: Science Press (China)
Abstract: ▾ Sharp changes in lithology and increases in grain size and sedimentation rate of sedimentary sequences from tectonically active basins are often used to indicate regional neotectonic activity. However, these conventional methods have been challenged by others who argue that the sedimentary evidence used to infer tectonism could be climatically induced. Therefore, some form of independent evidence or sedimentary criteria are required to discriminate between these two alternatives. Seismites, sedimentary structures preserved in lacustrine or marine stratigraphic sequences caused by seismic shaking, are reliable indicators of regional neotectonic activity. Lacustrine/Marine paleoseismology, an emerging cross-field, can extend the record of strong earthquakes and deepen the understanding of fault zone activity by studying seismites preserved in subaqueous sedimentary sequences. In this paper, we use the Dead Sea Basin and Qaidam Basin as examples to understand regional neotectonic activity from the perspective of subaqueous paleoseismology. The Dead Sea Basin is the deepest and largest continental tectonic structure in the world. A 457 m deep core(ICDP Core 5017-1)was recovered from the Dead Sea depocenter(31°30′29″N, 35°28′16″E) during 2010~2011. The bottom of the core was dated back to 220 ka. In situ folded layers and intraclast breccia layer in the core are identified as earthquake indicators, based on their resemblance to the lake outcrop observations of seismites that are known to be earthquake-induced. Based on the Kelvin-Helmholtz instability, we model the ground acceleration needed to produce each seismite by using the physical properties of the Dead Sea deposits. We invert acceleration for earthquake magnitude by considering regional earthquake ground motion attenuation, fault geometry, and other constraints. Based on the magnitude constraints, we develop a 220 ka-long record of MW ≥7 earthquakes. The record comprises 151 MW ≥7 events. The record shows a clustered earthquake recurrence pattern and a group-fault temporal clustering model, and reveals an unexpectedly high seismicity rate on a slow-slipping plate boundary. The Qaidam Basin is the largest topographic depression on the Tibetan Plateau that was formed by the ongoing India-Asia collision. The northeastward growth of the Tibetan Plateau formed a series of sub-parallel NW-SE-trending folds over a distance of ca. 300 km in the western Qaidam Basin. A 723 m deep core was drilled in the basin on the crest of one such fold, the Jianshan Anticline(38°21′9.46″N, 92°16′24.72″E) during 2010~2011. In this study, we focus on the upper 260 m of the core. Paleomagnetic dating constrains the age of the studied core interval to ca. 3.6~1.6 Ma. Sedimentological analysis reveals micro-faults, soft-sediment deformation, slumps, and detachment surfaces preserved in the core interval, which we interpret as paleoearthquake indicators. We recover a 2-Ma seismite sequence comprising 164 MW ≥5 events. The seismite sequence is relatively more complete during 3.6~2.7 Ma, which comprises 126 events and five seismite clusters. This suggests that the rate of tectonic strain accommodated by the folds/thrusts in the region varies in time and thus reveals episodic local deformation. During the clusters, regional deformation is concentrated more in the fold-and-thrust system than along regional major strike-slip faults. © 2022, Science Press (China). All rights reserved.
2712.
Prospects of gas production from the vertically heterogeneous hydrate reservoirs through depressurization in the Mallik site of Canada
Energy Reports,
82273-2287
2022
ISSN: 23524847
Publisher: Elsevier Ltd
Keywords:▾
Dissociation; Energy resources; Gases; Hydration; Methane; Natural gas; Natural gas deposits; Petroleum reservoir engineering; Petroleum reservoirs; Submarine geology, Depressurizations; Gas productions; Heterogeneous; Mallik site; Methane gas; Natural gas hydrates; Natural gas-hydrates; Production efficiency; Production performance; Reservoir models, Gas hydrates
Abstract: ▾ Natural gas hydrate (NGH) is a clean and efficient energy resource with extensive distribution in the permafrost regions and marine sediments. A few short-term production tests focusing on reservoir depressurization have been conducted in recent years. However, the long-term production performance and the transient evolution characteristics of reservoir properties are not well known. In this work, a more realistic hydrate-reservoir model that considers the heterogeneity of permeability, porosity and hydrate saturation is constructed, according to the available geological data at the Mallik site. The model is validated by reproducing the field depressurization test. The main purposes of this work are to evaluate the long-term gas production performance and to analyze the unique multiphase flow behaviors from the validated geologically descriptive hydrate-reservoir model. The results indicate that the long-term gas production through depressurization from hydrate reservoirs at the Mallik site is technically feasible, but the gas production efficiency is generally modest. The hydrate dissociation front in HBS is strongly affected by the reservoir heterogeneity and shows a unique dissociation front. The vertically heterogeneous HBS is beneficial for depressurization production compared to the massive hydrate reservoirs. Furthermore, the vertically heterogeneous hydrate-reservoir with low permeability of clay-layer can effectively block methane gas diffusion in the vertical direction. These emphasize that constructing realistic reservoir models is very important to accurately predict the hydrate production performance. At the end of 1-year depressurization, a total of 1.80 × 106 ST m3 of methane gas can be produced from the validated hydrate-reservoir, while which is far from the commercial value. In addition, reducing the production pressure in the wellbore is beneficial for increasing gas production volume, but is not conducive to improving the hydrate production efficiency at the Mallik site. © 2022 The Author(s)
2711.
Transformation of low-molecular-weight organic acids by microbial endoliths in subsurface mafic and ultramafic igneous rock
Environmental Microbiology
2022
2710.
Sulfate (re-) cycling in the oceanic crust: Effects of seawater-rock interaction, sulfur reduction and temperature on the abundance and isotope composition of anhydrite
Geochimica et Cosmochimica Acta,
31765--90
2022