Earth-Science Reviews

Article	Citations
The Orphan Basin: A review of basin evolution, structure, stratigraphy and petroleum systems	348
Geologic, geomorphic, tectonic, and paleoclimatic controls on the distribution and preservation of Chicxulub distal ejecta: A global perspective	239
Episodic kilometre-scale burial and exhumation and the importance of missing section	221
Multiscale lithospheric buckling dominates the Cenozoic subsidence and deformation of the Qaidam Basin: A new model for the growth of the northern Tibetan Plateau	212
Deep lithosphere of the North China Craton archives the fate of the Paleo-Asian Ocean	196
Environmental controls on very high δ238U values in reducing sediments: Implications for Neoproterozoic seawater records	194
Constraints on the formation of basaltic magmas. Comment on “Lithosphere thickness controls the extent of mantle melting, depth of melt extraction and basalt compositions in all tectonic settings on E	177
Paradigm shift for controls on basalt magmatism: Discussion with Lustrino et al on the paper I recently published in Earth-Science Reviews	175
Array processing techniques for analyzing global geophysical observation networks: Comprehensive analysis and typical applications	160
Urban evapotranspiration and its effects on water budget and energy balance: Review and perspectives	157
Editorial Board	156
Reply to: Comment on the paper by Barreca et al.: “The Strait of Messina: Seismotectonics and the source of the 1908 earthquake” by G. Barreca, F. Gross, L. Scarfì, M. Aloisi, C. Monaco, S. Krastel (E	155
Editorial Board	154
Comment on “Ichnological analysis: A tool to characterize deep-marine processes and sediments” by Francisco J. Rodriguez-Tovar [Earth-Science Reviews, 228 (2022), 104014]	154
Shale gas geochemistry in the Sichuan Basin, China	153
Reply to the comment on “Ichnological analysis: A tool to characterize deep-marine processes and sediments” by Francisco J. Rodríguez-Tovar [Earth-Science Reviews, 228 (2022), 104014]	143
Comment on the paper by Barreca et al.: “The Strait of Messina: Seismotectonics and the source of the 1908 earthquake” [Earth-Science Reviews 218, 2021, 103685]	141
Kerogen-specific isotope variations during the end-Permian mass extinction in South China	140
Comment on “A new classification system for mixed (turbidite-contourite) depositional systems: Examples, conceptual models and diagnostic criteria for modern and ancient records” by S. Rodrigues, F.J.	136
Tubarium construction in the Retiolitinae (Graptolithina, Axonophora)	135
Comment on “Towards improved USLE-based soil erosion modelling in India: A review of prevalent pitfalls and implementation of exemplar methods” by Majhi et al. (2021), Earth-Science Reviews 221, 10378	133
Detrital zircon geochronology and related evidence from clastic sediments in the Kyrenia Range, N Cyprus: Implications for the Mesozoic-Cenozoic erosional history and tectonics of southern Anatolia	131
The concept of oligotrophy applied to the fossil record	128
The conundrums of the postglacial tectonic response of the Fennoscandian and Canadian Shields	125
Precambrian geology of India	121

A review of new detrital zircon U-Pb ages from the Mogok area of Myanmar: Implications for the stratigraphy and early tectonic evolution of the Mogok Metamorphic Belt (MMB)	114
Grain-size variability and formation process of lowstand river sediments in the Japanese Islands: A review and outlook	105
Fast-eroding Taiwan and transfer of orogenic sediment to forearc basins and trenches in the Philippine and South China seas	98
Mantle micro-block beneath the Indian Ocean and its implications on the continental rift-drift-collision of the Tethyan evolution	96
Evidence of “Lake Nyos-type” behavior in the geological record: A review	94
Cycling and behavior of 230Th in the Arctic Ocean: Insights from sedimentary archives	89
The effects of large-scale forest disturbances on hydrology – An overview with special emphasis on karst aquifer systems	89
(Paleo)oceanography of semi-enclosed seas with a focus on the Mediterranean region; Insights from basic theory	89
The Drake Passage asthenospheric and oceanic gateway	88
Lower Palaeozoic-Paleogene geological development of a deep-water rift (Güzelsu Corridor) along the northern continental margin of the Southern Neotethys in the Eastern Mediterranean region: Evidence	86
Tectonic imprints in Permian paleomagnetic data of Morocco	86
An early Precambrian “orogenic belt” exhumed by the Phanerozoic tectonic events: A case study of the eastern North China Craton	84
Application of different radiogenic isotope systems and cyclostratigraphy in the dating of sedimentary rocks	84
Multi-phase heat transfer in porous and fractured rock	84
The problems of the Anthropocene in the Geologic Time Scale, and beyond	82
A systematic review of predictor screening methods for downscaling of numerical climate models	82
A review on the interfacial properties of caprock/CO2/brine system-implications for structural integrity of deep saline aquifers during geological carbon storage	82
Editorial Board	81
Gas hydrate characterization in sediments via x-ray microcomputed tomography	79
A comprehensive review of interwell interference in shale reservoirs	79
Complexities of regulating climate by promoting marine primary production with ocean iron fertilization	78
Devonian paleoclimate and its drivers: A reassessment based on a new conodont δ18O record from South China	78
Neoichnology of siliciclastic shallow-marine environments: Invertebrates, traces, and environmental conditions	77
Sediment routing systems of the eastern red sea rifted margin	73
The Mediterranean Sea and the Gulf of Cadiz as a natural laboratory for paleotsunami research: Recent advancements	72
Comment on “Discussion: Extracting thermal history from low temperature thermochronology/A comment on the recent exchanges between Vermeesch and Tian and Gallagher and Ketcham”, by Paul Green and Ian	72
Reply to the discussion paper by P. Sümegi and S. Gulyás: Some notes on the interpretation and reliability of malacological proxies in paleotemperature reconstructions from loess- comments to Obreht e	71
Reply to comments by Thilo Rennert on “Biogeochemical cycling of iron (hydr-)oxides and its impact on organic carbon turnover in coastal wetlands: A global synthesis and perspective”. Earth-Science Re	71
Discordant forearc deposition and volcanism preceding late-Cretaceous subduction shutdown in Marlborough, north-eastern South Island, New Zealand	71
Editorial Board	70
Geotectonic settings of Variscan explosive volcanism in the light of Famennian tuffites provenance from southern Poland	69
Long-period astronomical forcing of climatic and biological evolution during the late Paleozoic icehouse-to-greenhouse transition	69
The Mesozoic Iberia-Eurasia diffuse plate boundary: A wide domain of distributed transtensional deformation progressively focusing along the North Pyrenean Zone	68
Evolution of the Eastern Red Sea Rifted margin: morphology, uplift processes and source-to-sink dynamics	68
An embryonic fold and thrust belt south of the Himalayan morphological front: Examples from the Central Nepal and Darjeeling piedmonts	67
Cycles of ∼32.5 My and ∼26.2 My in correlated episodes of continental flood basalts (CFBs), hyper-thermal climate pulses, anoxic oceans, and mass extinctions over the last 260 My: Connections between	66
A review of Paleozoic phytoplankton biodiversity: Driver for major evolutionary events?	66
Evolution of eastern Asia river systems reconstructed by the mineralogy and detrital-zircon geochronology of modern Red River and coastal Vietnam river sand	65
Matching mid-to-latest Carboniferous pole path segments for eastern Australia and northern Armorica indicate a late Carboniferous Pangea-B configuration and a mid Carboniferous inertial interchange tr	64
Tectonostratigraphic evolution and significance of the Afar Depression	62
Envisioning faults beyond the framework of fracture mechanics	61
Evaluating tomotectonic plate reconstructions using geodynamic models with data assimilation, the case for North America	61
Miocene–Quaternary tectonic, kinematic and sedimentary evolution of the eastern Mediterranean Sea: A regional synthesis	60
Dispersal mechanism of fine-grained sediment in the modern mud belt of the East China Sea	60
Tetrapod turnover during the Permo-Triassic transition explained by temperature change	59
South Georgia microcontinent: Displaced fragment of the southernmost Andes	58
Geochemistry of metasedimentary restitic rocks and implications for melting conditions and metal potential of crustal felsic magmas	58
Jolts in the Jade factory: A route for subduction fluids and their implications for mantle wedge seismicity	58
Loess structure: Evolution and a scale-based classification	58
Conservation, preparation and imaging of diverse ambers and their inclusions	56

Atmospheric phosphorus and its geochemical cycling: Fundamentals, progress, and perspectives	56
The legacy of the Tethys Ocean: Anoxic seas, evaporitic basins, and megalakes in the Cenozoic of Central Europe	55
New perspectives on offshore groundwater exploration through integrated sequence-stratigraphy and source-to-sink analysis: Insights from the late Quaternary succession of the western Central Adriatic	53
Snowmelt erosion: A review	53
The Southern Granulite Terrane, India: The saga of over 2 billion years of Earth's history	53
Episodes of post-Caledonian burial and exhumation in Greenland and Fennoscandia	53
The Offset Dykes in the North and East Range of the Sudbury impact structure, Canada: A synthesis	52
Synthesis of chronostratigraphic data and methods in the Georgia Basin, Canada, with implications for convergent-margin basin chronology	52
Marine chemical structure during the Cambrian explosion	52
Lithospheric weakspots, not hotspots: New England-Quebec and Shenandoah anorogenic magmatism in the context of global plate tectonics, intraplate stress and LIPs	51
Impact of benthos on morphodynamics from a modeling perspective	51
Recent technological and methodological advances for the investigation of landslide dams	51
The Yanshanian Movement in Western Liaoning, northeastern North China Craton	49
Radium isotopes as submarine groundwater discharge (SGD) tracers: Review and recommendations	49
Nitrogen cycling during the Mesoproterozoic as informed by the 1400 million year old Xiamaling Formation	48
Vent distribution and sub-volcanic systems: Myths, fallacies, and some plausible facts	48
Mesozoic–Cenozoic tectonic evolution and dynamics of the Songliao Basin, NE Asia: Implications for the closure of the Paleo-Asian Ocean and Mongol-Okhotsk Ocean and subduction of the Paleo-Pacific Oce	48
Ichnological analysis: A tool to characterize deep-marine processes and sediments	47
Advancements in multi-rupture time-dependent seismic hazard modeling, including fault interaction	47
Experimental measurements and characterization models of caprock breakthrough pressure for CO2 geological storage	47
Evolution of the East Gondwana convergent margin in Antarctica, southern Australia and New Zealand from the Neoproterozoic to latest Devonian	47
Biomarkers in fossil resins and their palaeoecological significance	46
Balkanatolia: The insular mammalian biogeographic province that partly paved the way to the Grande Coupure	46
Hadean to early Mesoarchean rocks and zircons in the North China Craton: A review	46
Paleozoic collisional belt of the South Tien Shan: A review	45
Calibrating the temporal and spatial dynamics of the Ediacaran - Cambrian radiation of animals	45
A review of geological evidence bearing on proposed Cenozoic land connections between Madagascar and Africa and its relevance to biogeography	45
High-resolution Early Triassic ammonoid biostratigraphy of South Tibet, China and implications for global correlations	44
The Samail subduction zone dilemma: Geochronology of high-pressure rocks from the Saih Hatat window, Oman, reveals juxtaposition of two subduction zones with contrasting thermal histories	44
Focus on the nonlinear infiltration process in deep vadose zone	44
Evolution of paleo-climate and seawater pH from the late Permian to postindustrial periods recorded by boron isotopes and B/Ca in biogenic carbonates	44
Sardinia and the Alpine cycle: A tectono-sedimentary history at the Western Tethys edge	43
Cross-propagation of the western Alpine orogen from early to late deformation stages: Evidence from the Internal Zones and implications for restoration	43
New geochemical identification fingerprints of volcanism during the Ordovician-Silurian transition and its implications for biological and environmental evolution	43
Inorganic geochemistry of lake sediments: A review of analytical techniques and guidelines for data interpretation	42
Abrupt climate change in arid central Asia during the Holocene: A review	42
Magnetostratigraphic dating of earliest hominin sites in Europe	42
Forecasted weakening of Atlantic overturning circulation could amplify future relative sea-level rise in the Mediterranean: A review of climate and tide-gauge data links	42
Quantifying the pattern of organic carbon burial through Cretaceous Oceanic Anoxic Event 2	41
Principles of seismic stratigraphy and seismic geomorphology I: Extracting geologic insights from seismic data	41
Mechanics of methane bubbles in consolidated aquatic muds	41
Volcanic history of the Derceto large igneous province, Astkhik Planum, Venus	41
Comparison of thermodynamic data files for PHREEQC	40
Convergent margin metallogenic cycles: A window to secular changes in Earth's tectonic evolution	40
Synthesis of the distribution of subsidence of the lower Ganges-Brahmaputra Delta, Bangladesh	40
New Maps of Global Geological Provinces and Tectonic Plates	39
Nature and development of the South Tianshan-Solonker suture zone	39
Archean continental crustal growth and reworking of the North China Craton: Constraints from zircon U Pb age and Hf isotopic composition	39
A critical review on pore to continuum scale imaging techniques for enhanced shale gas recovery	39
Early–middle Permian ecosystems of equatorial Pangaea: Integrated multi-stratigraphic and palaeontological review of the Permian of Mallorca (Balearic Islands, western Mediterranean)	39
Desiccation cracking of soils: A review of investigation approaches, underlying mechanisms, and influencing factors	39
Decoding the onset of ca. 3.8 Ga continental nuclei in Anshan, North China: A review integrated with 1:10,000 geological mapping, zircon U–Pb dating, and Si–O–Nd–Hf–W isotopes	39
Deep-water depositional systems supplied by shelf-incising submarine canyons: Recognition and significance in the geologic record	38
Tsunami excitation in the outer wedge of global subduction zones	38
A review of the non-avian theropod track record and the implications for the Ontogenetic Niche Shift model	38
Post-collisional porphyry copper deposits in Tibet: An overview	38
Morphology and distribution of submerged palaeoshorelines: Insights from the North West Shelf of Australia	37
Provenance and genesis of karstic bauxite deposits in China: Implications for the formation of super-large karstic bauxite deposits	37
Bayesian back analysis of unsaturated hydraulic parameters for rainfall-induced slope failure: A review	37
Grain size from source to sink – modern and ancient fining rates	37
Opposite thrust systems under the Subei-South Yellow Sea Basin: A synthesis on the closure of the eastern Tethyan Ocean	37
An updated internet-based Global Paleomagnetic Database	36
Towards interactive global paleogeographic maps, new reconstructions at 60, 40 and 20 Ma	36
Plate tectonic modelling and the energy transition	36
Asynchronous palaeosol development during the past 20 ka in response to climate change across the dune fields of the Asian summer monsoonal boundary, northern China	36
Sergipe-Alagoas Basin, Northeast Brazil: A reference basin for studies on the early history of the South Atlantic Ocean	36
Incipient ocean spreading beneath the Arabian shield	35
Synchrony of carbon cycle fluctuations, volcanism and orbital forcing during the Early Cretaceous	35
Sedimentary brGDGTs in China: An overview of modern observations and proposed land Holocene paleotemperature records	35
Volcanic phosphorus spikes associated with supercontinent assembly supported the evolution of land plants	35
Mercury contents and isotope ratios from diverse depositional environments across the Triassic–Jurassic Boundary: Towards a more robust mercury proxy for large igneous province magmatism	35
How does soil water status influence the fate of soil organic matter? A review of processes across scales	35
Paleoproterozoic accretion and assembly of the Western Block of North China: A new model	34
Sediment oxygen consumption: Role in the global marine carbon cycle	34
Dense and long-term monitoring of earth surface processes with passive RFID — a review	34
Earth’s surface oxygenation and the rise of eukaryotic life: Relationships to the Lomagundi positive carbon isotope excursion revisited	34
Radium-226 in the global ocean as a tracer of thermohaline circulation: Synthesizing half a century of observations	34
Review of volcanic reservoir geology in China	34
Evolution of the Laurentide and Innuitian ice sheets prior to the Last Glacial Maximum (115 ka to 25 ka)	34
Defrosting northern catchments: Fluvial effects of permafrost degradation	34

Progressive tectonic evolution from crustal shortening to mid-lower crustal expansion in the southeast Tibetan Plateau: A synthesis of structural and thermochronological insights	34
Mechanisms for biocrust-modulated runoff generation – A review	34
Remote sensing algorithms for particulate inorganic carbon (PIC) and the global cycle of PIC	33
Representing the role of soil moisture on erosion resistance in sediment models: Challenges and opportunities	33
Cenozoic evolution of the Qaidam basin and implications for the growth of the northern Tibetan plateau: A review	33
Crustal melting and suprasolidus phase equilibria: From first principles to the state-of-the-art	33
Granitic record of the assembly of the Asian continent	33
Analyses from a validated global U Pb detrital zircon database: Enhanced methods for filtering discordant U Pb zircon analyses and optimizing crystallization age estimates	33
Exposing basement terranes of the North Australian Craton	33
Moraine-dammed glacial lakes and threat of glacial debris flows in South-East Kazakhstan	32
Contrasting characteristics, changes, and linkages of permafrost between the Arctic and the Third Pole	32
Landslide susceptibility maps of Italy: Lesson learnt from dealing with multiple landslide types and the uneven spatial distribution of the national inventory	32
The trials and tribulations of the Hawaii hot spot model	31
The Silurian–Devonian terrestrial revolution: Diversity patterns and sampling bias of the vascular plant macrofossil record	31
Phanerozoic paleotemperatures: The earth’s changing climate during the last 540 million years	31
Rill flow velocity and resistance law: A review	31
Sources, characteristics and climate impact of light-absorbing aerosols over the Tibetan Plateau	31
Oil content and resource quality evaluation methods for lacustrine shale: A review and a novel three-dimensional quality evaluation model	31
An overview of monitoring methods for assessing the performance of nature-based solutions against natural hazards	30
Nutrient enrichment and climate warming drive carbon production of global lake ecosystems	30
Fringed Patagonian tableland: One of Earth's largest and oldest landslide terrains	30
Deep learning in pore scale imaging and modeling	30
The Bangong-Nujiang Suture Zone, Tibet Plateau: Its role in the tectonic evolution of the eastern Tethys Ocean	30
Mercury stable isotopes revealing the atmospheric mercury circulation: A review of particulate bound mercury in China	30
Extending full-plate tectonic models into deep time: Linking the Neoproterozoic and the Phanerozoic	30
Valley incision chronologies from alluvium-filled cave systems	30
Rebuttal of Sweatman, Powell, and West's “Rejection of Holliday et al.'s alleged refutation of the Younger Dryas Impact Hypothesis”	30
Research status and prospects of CO2 geological sequestration technology from onshore to offshore: A review	29
Deposition and termination of Neoproterozoic iron formations (NIFs): New insights from NIFs in China	29
Termination of Sturtian glaciation with protracted, multiple volcanic eruptions	29
Trends and geographic variation in adverse impacts of nitrogen use in Europe on human health, climate, and ecosystems: A review	29
Corrigendum to “Arc magmatic evolution and porphyry copper deposit formation under compressional regime: A geochemical perspective from the Toquepala arc in Southern Peru” [Earth Science Reviews, 240	29
Zirconium and its stable isotopes in igneous systems	29
Is hyperaccumulation a viable hypothesis for organic associations of minor elements in coals?	29
Overland flow resistance: A review	29
The Ivrea-Verbano tectonic evolution: The role of the crust-mantle interactions in rifting localization	29
Comprehensive review of CO2 geological storage: Exploring principles, mechanisms, and prospects	29
Degradation and local growth of “Xing'an-Baikal” permafrost responding to climate warming and the consequences	28
A pulse of seafloor oxygenation at the Late Devonian Frasnian-Famennian boundary in South China	28
Age, formation mechanisms, spatial extent, and geodynamic effects of the eastern and northeastern Asian big mantle wedges	28
Climate-driven compositional modifications of arc volcanoes along the East Equatorial Pacific Margin — The magmatic response to a cooling planet	28
Natural records of supercritical fluids in subduction zones	28
From peridotite to listvenite – perspectives on the processes, mechanisms and settings of ultramafic mineral carbonation to quartz-magnesite rocks	28
A review of geophysical research: Perspective into the Indian Ocean Geoid Low	28
Evolution mechanisms, impacts, and variations of the vortices originated from the Tibetan Plateau	28
3D geometric modelling of the Northwest Pacific slabs: A review and new high-precision model	28
Aerosol-cloud interactions over the Tibetan Plateau: An overview	28
Multi-scale ocean dynamical processes in the Indo-Pacific Convergence Zone and their climatic and ecological effects	28
Deeper underground: Cosmogenic burial dating of cave-deposited alluvium to reconstruct long-term fluvial landscape evolution	27
Structural evolution of the superimposed Provençal and Subalpine fold-thrust belts (SE France)	27
Cenozoic lithospheric architecture and metallogenesis in Southeastern Tibet	27
Comment on Li et al. (2023): A dynamic 2000—540 Ma Earth history: From cratonic amalgamation to the age of supercontinent cycle	27
Measuring, modelling and managing gully erosion at large scales: A state of the art	27
Downhole logging data for time series analysis and cyclostratigraphy	27
A chronological database assessing the late Quaternary palaeoenvironmental record from fluvial sediments in southwestern Africa	27
A review of the land snail faunas of the European Cenozoic – composition, diversity and turnovers	27
Remote sensing for cost-effective blue carbon accounting	27
Some notes on the interpretation and reliability of malacological proxies in paleotemperature reconstructions from loess- comments to Obreht et al.'s “A critical reevaluation of paleoclimate proxy rec	26
Editorial Board	26
Editorial Board	26
Rates of geological processes	26
Early–Middle Triassic fluvial ecosystems of Mallorca (Balearic Islands): Biotic communities and environmental evolution in the equatorial western peri-Tethys	26
The elusive continental rise: Insights from residual bathymetry analysis of the Northwest Atlantic margin	26
Comment on the paper by Buono et al. “Dynamics of degassing in evolved alkaline magmas: Petrological, experimental and theoretical insights” (Earth Science Reviews, 211 (2020), 103402)	26
The importance of tangential motion in the Central Alps: Kinematic analysis and Rb Sr dating of mylonitic rocks from the Pennine nappes in the eastern Central Alps	26
Editorial Board	25
Flared slopes: The work of water or fire?	25
Editorial Board	25
High-resolution sedimentology, ichnology, and benthic marine redox conditions from Late Permian to the earliest Triassic at Shangsi, South China: Local, regional, and global signals and driving mechan	25
The sediment routing systems of Northern South America since 250 Ma	25
Chemical characteristics of modern deep-sea metalliferous sediments in closed versus open basins, with emphasis on rare-earth elements and Nd isotopes	25
Editorial Board	25
Editorial Board	25
Editorial Board	25
Influence of continental rifting on sedimentation and its provenance and geodynamic implications: An example from late Paleoproterozoic Chandil Formation, eastern India	25
Morphology and origin of alluvial step-pools: A synthesis of experimental and field data from formative flows	25
Dynamics of Tethyan marine de‑oxygenation and relationship to S-N-P cycles during the Permian-Triassic boundary crisis	25
Editorial Board	25
Secular variability of the thermal regimes of continental flood basalts in large igneous provinces since the Late Paleozoic: Implications for the supercontinent cycle	25
Early paleozoic tectonics and paleogeography of the Eastern Arctic and Siberia: Review of paleomagnetic and geologic data for the De Long Islands	24
Biological albedo reduction on ice sheets, glaciers, and snowfields	24
Contemporaneous closure of the Paleo-Asian Ocean in the Middle-Late Triassic: A synthesis of new evidence and tectonic implications for the final assembly of Pangea	24
Geophysical and geochemical constraints on the origin of Holocene intraplate volcanism in East Asia	24
High-resolution geochronology of sedimentary strata by U-Pb CA-ID-TIMS zircon geochronology: A review	24
Structural architecture and Late Cretaceous exhumation history of the Saih Hatat Dome (Oman), a review based on existing data and semi-restorable cross-sections	24
Interactions between vegetation and river morphodynamics. Part I: Research clarifications and challenges	24
Comment on “The Younger Dryas impact hypothesis: A review of the evidence”, by Martin B. Sweatman (2021), Earth-Science Reviews 218, 103677	24
Discussion of the paper “Loess genesis and worldwide distribution” by Yanrong Li, Wenhui Shi, Adnan Aydin, et al.	24
The links between Neoproterozoic tectonics, paleoenvironment and Cambrian explosion in the Yangtze Block, China	24
Evolution of the Zagros sector of Neo-Tethys: Tectonic and magmatic events that shaped its rifting, seafloor spreading and subduction history	24
Formation of giant copper deposits in Tibet driven by tearing of the subducted Indian plate	23
Fracture sets and sequencing	23
Landslide monitoring using seismic ambient noise correlation: challenges and applications	23
Layered intrusions: Fundamentals, novel observations and concepts, and controversial issues	23
Stromatolites as geochemical archives to reconstruct microbial habitats through deep time: Potential and pitfalls of novel radiogenic and stable isotope systems	23