Latitudinal temperature gradients are a defining characteristic of the climate system. Using thermometric indicators, including δ18O, plant and animal fossils, glycerol dialkyl glycerol tetraether ...(GDGT) proxies, and clumped isotope estimates, we document marine and terrestrial temperature gradients for the latest Cretaceous, Late Paleocene-Early Eocene, Early Oligocene, Pliocene, and Recent. The changes in gradients reflect the transition greenhouse to icehouse conditions. The evolution of latitudinal temperature gradients in marine and terrestrial realms are similar but has some distinctive differences. Marine temperatures are generally warmer than those on land. Except for the Late Paleocene-Early Eocene, the marine records show distinct inflection points at ~30° and ~50° latitude indicating the existence of frontal systems in the ocean. Except for the Late Paleocene-Early Eocene, the marine records show an increasingly steeper trend, from latest Cretaceous through Recent, being most pronounced after the Early Oligocene greenhouse-icehouse transition. This trend reflects the increasing intensity of high-latitude and polar cooling as the icehouse state developed. During the Late Paleocene-Early Eocene the oceans were characterized by slightly warmer tropics and much warmer higher latitudes than at present. The continents have generally had tropical temperatures like those of today, varying by <5 °C. Higher latitude temperatures cooled during the latest Cretaceous, became much warmer during the Late Paleocene-Early Eocene, then cooled during the Early Oligocene and have become increasingly colder since then. The results suggest that there is a climate thermostat mechanism, probably related to greenhouse gas concentrations, that ameliorates tropical warming by redistributing warmth to the poles in the greenhouse world. That mechanism broke down as greenhouse gas concentrations declined resulting in the conversion from greenhouse to icehouse conditions.
As a paradigm of greenhouse climate in Earth's history, the Cretaceous provides significant rock records of global climate changes under conditions of greenhouse climate. The Songliao Basin, among ...the longest duration (85–90m.y.) of continental sedimentary basins, provides an excellent opportunity to recover a nearly complete Cretaceous terrestrial sedimentary record. Extensive lake deposits, ten-kilometers deep and covering an area of 260,000km2 of the Songliao Basin, provide unique, detailed records that can be tied to the global stratigraphic time scale, thereby improving our understanding of the continental paleoclimate and ecological system. The two coreholes at SKIs and SKIn sites were drilled into this basin and completed with a total length of 2485.89m of recovered core that spanned the complete middle-to-Upper Cretaceous strata in the basin. The unique geological setting of long-term continuous subsidence within the largest Cretaceous landmass in the world — makes the Cretaceous Songliao Basin of northeastern China an ideal place to study Cretaceous climate change on the continent. This paper reviews the literature on the paleogeography and paleoclimate of the northern East Asia and the Songliao Basin during the Cretaceous. Based on the climatologically sensitive deposits, oxygen isotope studies, and paleontology, the climate during the Cretaceous in the Songliao Basin was temperate and humid with relatively abundant rainfall. During the period, significant changes – four cooling, three warming, and three semiarid events – are generally consistent with the oxygen isotope data from East Asia, and the four cooling events, in Berriasian–Valanginian, Aptian–Albian, early Santonian, and Campanian–Maastrichtian, may be related to potential glaciations in Cretaceous.
► We analyze the Cretaceous paleogeography and paleoclimate in the Songliao Basin. ► The basin located in the Northern Hemisphere middle latitude spans up to 85–90m.y. ► Tectonic activity and water supply controlled the character of sediment facies. ► The climate of the basin was temperate and humid with relatively abundant rainfall. ► There were four cooling, three warming and three semiarid events in the Cretaceous.
During the Early Cretaceous, significant tectonic regime transformation occurred in East China. Meanwhile, the Jehol Biota, which contains world‐famous feathered dinosaurs, flourished. However, few ...studies have been conducted to investigate the influence of tectonic regime transformation on regional topography and climates and the possible climatic causes of the unique characteristics of these dinosaurs. Here, we address these issues by applying clumped isotope paleothermometry to Early Cretaceous carbonates in NE China. In the Sihetun area, the mean annual paleotemperature derived from paleosol carbonates was 5.9 ± 1.7°C, and the paleoelevation was 2.8–4.1 km during the Early Cretaceous. The topographic evolution was closely related to the subduction of the paleo‐Pacific plate beneath East Asia during this period. Our results suggest a high altitude and cold habitat with frozen winters for the Jehol Biota in the Sihetun area, which implies possible climate‐Keywords:influenced evolution of the feathered characteristic of the dinosaurs.
Plain Language Summary
During the Early Cretaceous, the Jehol Biota, especially the unique feathered dinosaurs, flourished in western Liaoning Province, China. As insulation devices, the feathers helped these nonavian dinosaurs resist the cold climate, although conventional opinions have suggested that the Early Cretaceous was a typical “greenhouse climate” world. Based on the clumped isotopes of the paleosol carbonates in the Sihetun area, our study estimates the paleotemperature and paleoaltitude of the living habitat of these feathered dinosaurs during the Early Cretaceous. We suggest that the feathered dinosaurs in NE China lived in a high‐altitude habitat with frozen winters and volcanic eruptions, which implies possible climate‐influenced evolution of the feathered characteristic of the dinosaurs. We also suggest that topographic change‐induced cooling was caused by significant tectonic regime transformation in East China.
Key Points
We analyze carbonate clumped isotopes to estimate the Early Cretaceous elevation of the habitat of feathered dinosaurs in NE China
The feathered dinosaurs lived in a high‐altitude habitat with freezing conditions in winter in NE China during the Early Cretaceous
Topographic changes were caused by the eastward subduction of the paleo‐Pacific plate
A large body of evidence suggests that there were extensive coastal mountains along the East Asian margin during the Late Cretaceous. However, current knowledge of the paleo-mountains — the period, ...range, and elevation — is limited. Therefore, direct paleoaltimetry is needed to validate and evaluate the paleo-mountains in East Asia. Our study area is Jiaolai Basin, which is located at the East Asian continental margin. We estimate the paleoelevation of Jiaolai Basin during the Late Cretaceous using carbonate clumped isotope paleothermometry. After correcting for seasonal preference, latitudinal difference, and secular climate change, we conclude that the paleoelevation of Jiaolai Basin was almost certainly ≥2.0 km at ∼80 Ma. Combined with the evidence from stratigraphy, paleogeography, and paleoclimatology, our results suggest that the existence of coastal mountains along East Asia during the Late Cretaceous is likely and the model of Okhotomorsk–East Asia collision is preferred.
•There were coastal mountains along the East Asian margin during the Late Cretaceous.•We applied clumped isotope paleothermometry to paleosol carbonates in Jiaolai Basin.•We quantitatively estimate the paleoelevation of the coastal mountains.•The paleoelevation was almost certainly ≥2 km.•The model of Okhotomorsk–East Asia collision is preferred.
Cretaceous climate data of the long-lived Cretaceous Songliao Basin (SB) in eastern Asia is correlated and compared with the Western Interior Seaway (WIS) on the northern American plate, in order to ...understand better the dynamics of the Earth's past ‘greenhouse’ climates. Nearly continuous Late Cretaceous terrestrial deposition in the Songliao Basin is represented by two cores totaling 2431m in length. The Turonian–Maastrichtian age of the section is based on integrated stratigraphy, and is comparable in age with Upper Cretaceous strata in the WIS. Being consistent with global trends, the dynamic Late Cretaceous climates of both the SB and WIS gradually cooled from the warmest Albian–Cenomanian time to the end of the Maastrichtian with several intervening warm periods as did the global climate. However regional differences existed, the Songliao Basin climate was humid to semi-humid, warm temperate–subtropical and the Western Interior Seaway was in the humid, warm temperate zone and experienced only moderate climatic changes. The shifts of oxygen isotope data in the Songliao Basin were frequent and abrupt, whereas WIS records more gradual change affected mainly by fresh-water runoff mixing with southern Tethyan and northern Arctic waters. Sedimentary cycles of eccentricity, obliquity and precession bands are recorded in both the SB and WIS basins. The sedimentary cycles in the WIS and SB are interpreted to be related to variations of the wet/dry runoff cycles, which indicate that orbital forcing played an important role in global climate change in Late Cretaceous. The most favorable condition for organic carbon burial in both the SB and WIS basin was bottom water anoxia regardless of the cause of the anoxia. But the organic carbon burial rate was usually much higher in the Songliao Lake than in the WI epeiric sea suggesting that giant lakes may serve as important sinks of atmospheric CO2. In both basins organic-rich deposits formed during a rise in water level and incursion of saline waters. The integration of paleoclimate data from Cretaceous marine deposits and terrestrial sedimentary record will promote our understanding of the Cretaceous ‘greenhouse’ climate change and may provide insights for a future greenhouse world.
The Jurassic is a crucial greenhouse period that witnessed a transition from the relatively colder Triassic to the relatively warmer Cretaceous. However, previous studies based on marine sections ...suggest different long-term paleotemperature trends throughout the Jurassic. Oxygen isotope (ẟ18O) values of temperate belemnite and bivalve fossils suggest a general cooling followed by a general warming trend during the Jurassic, whereas TEX86H and clumped isotope sea surface temperature records available for parts of this period appear consistent with a relatively warm and stable climate. The paucity of Middle Jurassic paleotemperature estimates limits efforts to investigate the above disagreement. Here, we apply clumped isotope (Δ47) thermometry to paleosol carbonates from the central part of East China to reconstruct terrestrial paleotemperatures and paleoatmospheric CO2 (pCO2) in the Middle Jurassic. After evaluating potential burial diagenesis and seasonality of soil carbonate accumulation, we suggest that terrestrial mean annual temperatures ranged from 30 ± 4 °C to 34 ± 4 °C and the estimated mean pCO2 was 1219 ± 519 ppmv in mid-latitude East China during the Middle Jurassic. Based on the compiled marine temperatures and our results, we conclude that the paleoclimate was relatively warm and stable from the Middle Jurassic to at least the Earliest Cretaceous (ca. 180–135 Ma). Our estimated Middle Jurassic pCO2 aligns with previous records, revealing minimal variations compared to the pCO2 observed during the Early Cretaceous. These findings imply a link between the consistent temperatures and the relatively stable pCO2 levels from the Middle Jurassic through the Early Cretaceous.
•We analyze clumped isotopes of paleosol carbonates in mid-latitude East China.•The mean annual terrestrial temperatures were 30–34 °C during the Middle Jurassic.•The eatimated pCO2 was 1219 ± 519 ppmv during the Middle Jurassic.•Our results are broadly consistent with coeval sea surface temperatures and pCO2.•The paleoclimate was relatively warm and stable during ca. 180–135 Ma.
As CO2 keeps emitting, it is urgent to project future climatic changes by quantitatively reconstructing deep time paleoclimate in high atmospheric CO2 concentrations. However, there are still ...unneglected discrepancies between the terrestrial temperatures based on the climatic proxies and climate models, especially at low latitudes, which limits our interpretation of the terrestrial responses to global climate changes at low latitudes. In this study, the clumped isotope concentrations (Δ47) and total mercury signals are analyzed for the uppermost Cretaceous-lowermost Paleogene strata in the low-latitude Nanxiong Basin, South China. After excluding the potential diagenesis by both recrystallization and solid-state reordering, our study presents an extremely high mean annual terrestrial temperature of ca. 30 °C in the low latitudes. Our result is significantly higher than the previous estimates and supports a hot and expanded tropics during the latest Cretaceous-earliest Paleocene (i.e., K-Pg boundary interval). In addition, we suggest that the hot climate was plausibly caused by Deccan Traps (DT) volcanism, although the mercury concentrations in the section show relatively low peaks during the main eruptions. We speculate that the mercury sequestration in the Nanxiong Basin may have been affected by the extremely hot and arid regional climate.
•We analyze clumped isotopes and total mercury signals in low-latitude Nanxiong Basin.•The mean annual terrestrial temperature was ∼30 °C during the K-Pg boundary interval.•The low-latitude continents were extremely hot during the K-Pg boundary interval.•The mercury sequestration may had been affected by the hot and arid climate.
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•We applied integrated methods to analyze the provenance of the Jiaolai Basin.•The provenance of the Jiaolai Basin had changed during the Late Cretaceous.•The provenance change ...revealed extensive topographic changes in East China.•The provenance change was attributed to a NW-SE compression event.
East China experienced crustal extensions during the Early Cretaceous and the latest Cretaceous-Cenozoic. For a long time, previous studies have recognized a short-lived compressional event between these two extensional regimes during the early Late Cretaceous but not much attention has been paid to it, although it may shed new light on the tectonic evolution of East Asia and the mechanism of the North China Craton Destruction. The Jiaolai Basin, located at the margin of East China, consists of a thick succession of Cretaceous sedimentary rocks and thus may help in further interpreting the mechanism and influence of the short-lived compressional event. Here, we apply integrated sedimentological methods to sandstone samples of both the Lower Cretaceous Laiyang Group and Upper Cretaceous Wangshi Group. Our findings suggest that there was a provenance change in the Jiaolai Basin from the Early Cretaceous granitic and metamorphic rock origin to the Late Cretaceous basic-intermediate volcanic origin. Combined with the zircon U-Pb ages, we conclude that the provenance change was caused by the uplift of the coastal mountains along the East Asian margin, from the relatively distal Sulu orogenic belt and Jiaobei Terrane during the Early Cretaceous to the intra-basinal volcanic rocks of the Qingshan Groupduring the Late Cretaceous. After careful evaluation of the provenance histories, orogenic exhumations, widespread unconformities and paleoclimate changes that occurred in sedimentary basins both along the East Asian margin and in the hinterland, we finally estimate the possible range of influence and extent of the short-lived compression event during the early Late Cretaceous.
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