Earth-Science Reviews最新文献

Accretionary orogens function as crucial sites for the generation of arc igneous rocks and continental crust, but the spatial and temporal distribution of arc igneous rocks and the link between the arc magmatic processes and crust generation within individual orogens remains poorly constrained. To address this issue, we have summarized published geochemical and zircon isotopic data for Paleozoic (∼460–280 Ma) mafic–intermediate–felsic igneous rocks within five individual belts from the Chinese Eastern Tianshan of the southern Central Asian Orogenic Belt (CAOB), which aim to explore the variations in magma sources (juvenile or reworked crust) and crustal thickness in response to tectonic and crustal evolution over time. This summary highlights the systematic variation in elemental and isotopic signatures of magmas in the Eastern Tianshan and makes it possible to quantitatively evaluate the crustal evolution and tectonic switch patterns. Repeated tectonic switches of the Eastern Tianshan trench-arc-basin system during subduction of the Kangguer oceanic plate appear to have occurred in two phases of the northern trench advance (ca. 460–381 Ma and 330–301 Ma, respectively) and the intervening trench retreat (ca. 380–331 Ma), as well as seem to have happened in the southern trench of the Kangguer Ocean with trench southward advance and northward retreat at ca. 360–331 Ma and 330–301 Ma, respectively. The estimated crustal growth in the Eastern Tianshan various from trench advance accompanied by significant crustal thickening (i.e., northern trench advance at ca. 460–421 Ma and southern trench advance at ca. 360–331 Ma, respectively) to northern trench retreat with crustal thinning (ca. 380–331 Ma). Most of the magma in the Eastern Tianshan was generated by crustal reworking or mixing.

It is unresolved when eolian processes began to significantly affect global mean sand composition and texture through abrasion and enhanced sorting. Reports of Proterozoic eolian textures and sedimentary structures are common, in particular from 1.8 Ga on, but the Archean (4.0–2.5 Ga) geologic record possesses only seven reported eolian occurrences which generally do not manifest more than a few diagnostic features of eolian transport. We investigate in detail sandstone units within the Moodies Group (ca. 3.22 Ga) of the Barberton Greenstone Belt, South Africa, one of the oldest well-preserved terrestrial–marine sandy successions. Eight examined locations show terrestrial facies associations, high degrees of compositional and textural maturity, and large-scale foresets; however, none show convincing evidence of eolian transport but several can be excluded with confidence. In comparison to recent eolian strata, grains are generally slightly too coarse-grained, too angular, and mostly too poorly sorted. The common presence of shale laminations, granules, rare pebbles, and shale rip-up clasts demonstrates that the investigated strata were either of aqueous origin or had been formed by eolian processes but were subsequently aqueously reworked. This is vexing because the sandy-gravelly fluvial, coastal floodplain, and estuarine depositional environments of Moodies Group strata may have been hospitable to potentially powerful and long-lasting Archean eolian processes. Early Archean eolian strata may have had a limited depositional area, may have been extensively reworked, or formed under non-actualistic conditions. Thus, the significance of eolian processes on early Earth and their potential contribution to the high degree of textural and compositional maturity of Archean quartzarenites remains poorly constrained.

Geological storage of CO₂ is a promising technique to mitigate anthropogenic CO₂ emissions. The effectiveness of CO₂ storage in the subsurface formations relies on various trapping mechanisms that immobilize the injected CO₂. Among these mechanisms, residual trapping has been identified as a critical factor, closely associated with residual CO₂ saturation. The extent of residual CO₂ saturation is strongly influenced by the petrophysical, physicochemical and hydrodynamic properties of CO₂/fluid/rock systems and operational conditions, thereby governing the overall residual trapping efficiency.

This article reviews the published experimental datasets on the initial and residual CO₂ saturation and analyzes the corresponding trapping efficiency for a range of in-situ CO₂/fluid/rock systems. We explore the factors that influence trapping efficiency, including wettability, rock type, rock properties, and flow rate. The gas saturations and trapping efficiencies of different gas types (i.e., CO₂, N₂, and H₂) are also discussed. Finally, we present the knowledge gaps and outline prospects for future research. This review establishes a state-of-art data repository of gas saturations in different conditions, enhancing our understanding of residual trapping in subsurface gas storage.

Upland soils constitute the second largest and the only manageable methane (CH₄) sink, yet current estimations remain substantially uncertain. This review identifies the primary sources of model uncertainties and emphasize the need for improved model accuracy and necessary comprehensiveness to better estimate upland soil CH₄uptake under global change. We highlight that the limitations of diffusion-reaction models include oversimplified assumptions of upland soils as constant CH₄sinks and insufficient parameterization of the microbial CH₄ oxidation constants. In process-based biogeochemical models, uncertainties stem from the omission of soil O₂ status and oversimplified Michaelis–Menten kinetics parameterization for upland soils. We also provide three suggestions for better addressing the spatiotemporal variations in soil CH₄ uptake globally. 1) Accounting for the balance between methanotrophy and methanogenesis is the key to accurately assessing CH₄ fluxes at fine to large scales. 2) Improved response curves of methanotrophy to soil moisture, temperature, and mineral nitrogen, as the most important regulators, are needed to correct the underestimated spatial variations in the size of the soil CH₄ sink globally. 3) Improving parameterizations based on the relationships between environmental factors and methanotrophic communities is necessary. Our synthesized model estimations and field observations reveal that inconsistent estimations of the spatial variations in forest soil CH₄ sinks, and the neglect of the drylands (arid and semiarid ecosystems) CH₄ sink are the major sources of uncertainty for global upland soil CH₄ sinks. Given the great potential of soil CH₄ uptake in mitigating the imbalanced global CH₄ budget, we emphasize the necessity of addressing the soil CH₄ exchanges in these key ecosystems, particularly under the impacts of global changes, by integrating continuous in-situ observations with improved models to fully account for the dynamics of the terrestrial CH₄ sink. This review contributes to a more accurate estimation, management, and optimization of global upland soil CH₄ sinks, aiding in the development of effective climate change mitigation strategies.

Deep and long-lived rifted basins host valuable information about tectonic evolution and environmental changes occurring in their surroundings throughout hundreds of millions of years. These basins, however, are hard to infer, because their deep parts are commonly obscured in seismic images and their structure is affected by several deformation phases that occurred during their long history.

The Levant Basin is a good example for a deep Tethyan basin that formed alongside Gondwana breakup. Unlike many Tethyan basins that were eroded and/or severely deformed during the Alpine orogeny, the Levant Basin has preserved a thick (>15 km), long-lived (>250 Myr), and continuous sedimentary record providing a world-class archive to study the role of post-rift subsidence and sediment supply on depocenter evolution. It exemplifies classic tectono-sedimentary problems, such as basin inversion and the mutual relationships between accommodation space, sediment supply, and sediment accumulation. Also, it provides valuable information about the ancient Tethyan margin, which were mostly destructed by the Alpine Orogeny.

We review the tectonic and sedimentary evolution of the Levant Basin. We synthesize regional seismic interpretations from previous studies utilizing thousands of kilometers of seismic lines and tens of wells in a unified dataset. Based on thickness analysis, we identify the syn-rift to post rift transition. The regional seismic horizon marking this transition is tied to dated horizons in wells providing a concrete age constraint of pre- 163 Ma (end of Callovian) for the end of rifting, which was previously debated. In addition, we show that rifting comprises at least two phases, which are equivalent to two extensional phases documented onshore: Permian to Middle-Triassic and late-Early to Middle-Jurassic. We further show that the early extensional structures (normal faults) approximately coincide with much younger contractional structures of the Syrian Arc Fold belt.

Analysis of 11-thickness maps showcase the 250 Myr evolution of sedimentary filling, opening a discussion about what controlled depocenter migration in relation to tectonic subsidence and sediment supply. We distinguish between periods during which near margin accumulation dominated versus periods during which more sediments accumulated in the deep basin. We explain these changes in light of sediment sources in surrounding continents and paths of transport. Marginal accumulation periods (syn-rift, early post-rift, and Pliocene-Quaternary) represents sediment supply from the nearby Levant (Arabia), whereas, deep basin accumulation periods represent sediment supply that was either provided from the water column (pelagic micro- and nano-fossils, Santonian to Mid-Eocene), or transported mostly from Africa with minimal accumulation along the Levant margin (during the Late-Eocene to Miocene).

This review is based on holistic approach fo