Paul E. Olsen

Columbia University | CU · Department of Earth and Environmental Sciences

Northeast China’s Early Cretaceous Yixian Formation preserves spectacular fossils that have proved extraordinarily important in testing evolutionary hypotheses involving the origin of birds and the distribution of feathers among nonavian dinosaurs. These fossils occur either flattened with soft tissue preservation (including feathers and color) in...

The end-Triassic extinction (ETE) on land was synchronous with the initial lavas of the Central Atlantic Magmatic Province (CAMP) and occurred just after the brief 26 thousand year (kyr) reverse geomagnetic polarity Chron E23r that can be used for global correlation. Lava-by-lava paleomagnetic secular variation data, previously reported from Morocc...

reptiles

Taylorsville Basin new site new finds

The Junggar Basin, northwest China, hosts continuous and well-exposed Late Triassic and Jurassic continental strata. Extensive coal, oil and gas deposits occur within the basin, and together with the high palaeolatitude locality and continental records of several Mesozoic geological events, make the sedimentary successions globally important. This...

Mesozoic continental basins of northern China, including the Junggar Basin, provide some of the most spectacular and important fossil assemblages in the world, but their climatic and environmental contexts have been shrouded in uncertainty. Here we examine the main factors that determine those contexts: palaeolatitude; the effects of changing atmos...

Vertebrate assemblages from the Junggar Basin in Xinjiang, China are the only ones known from palaeoarctic continental strata of Late Triassic and Early Jurassic age. Here we present a preliminary description of these new assemblages, focusing on the underappreciated Arctic palaeolatitude and winter freezing of this coal-bearing sequence. Mostly co...

We show that the Late Triassic-Early Jurassic continental Arctic experienced wintertime freezing conditions, despite the exceptionally high atmospheric CO 2 ( p CO 2 ), by quantitative identification of common lake ice-rafted debris (L-IRD) in the Junggar Basin of Xinjian, northwest China. This L-IRD consists of outsized (0.1-12 mm) lithic clasts ‘...

In contrast to the Triassic/Jurassic boundary, there is no consensus on the definition and age of the Norian/Rhaetian boundary (NRB), which hampers the global correlation of Rhaetian strata and thus interpretation of the pattern and driving mechanism of the end-Triassic mass extinction (ETE). Recent works show that a significant negative carbon iso...

This volume presents recent advances in our understanding of Mesozoic palaeontology, sedimentology and geochemistry of the Junggar Basin, China. This basin is of particular interest because it provides rare insights into life on the continents from a region that was at high latitudes during the Triassic and Jurassic.

The Early Cretaceous Jehol Biota in northeastern China significantly increased our understanding of the Mesozoic terrestrial ecosystem and the origin and evolution of a number of biological groups. The early evolutional phase of the Jehol Biota is best recorded in the Members 2 and 3 of the Dabeigou Formation (D-M2–3) in the Luanping Basin and thei...

Orbital cyclicity is a fundamental pacemaker of Earth’s climate system. The Newark–Hartford Basin (NHB) lake sediment record of eastern North America contains compelling geologic expressions of this cyclicity, reflecting variations of climatic conditions in tropical Pangea during the Late Triassic and earliest Jurassic (~233 to 199 Ma). Climate mod...

The White Mountain magma series is the largest Mesozoic felsic igneous province on the eastern North American margin. Previous geochronology suggests that magmatism occurred over 50 m.y., with ages for the oldest units apparently coeval with the ca. 201 Ma Central Atlantic Magmatic Province, the flood basalt province associated with the end-Triassi...

Abundant lake ice-rafted debris in Late Triassic and earliest Jurassic strata of the Junggar Basin of northwestern China (paleolatitude ~71°N) indicates that freezing winter temperatures typified the forested Arctic, despite a persistence of extremely high levels of atmospheric P co 2 (partial pressure of CO 2 ). Phylogenetic bracket analysis shows...

The Upper Triassic Chinle Formation, cropping out in and around Petrified Forest National Park (PFNP) in northern Arizona, U.S.A., preserves an important non-marine biotic and sedimentologic record of Late Triassic key Earth-life events. In 2013, the Colorado Plateau Coring Project (CPCP) obtained a 520-m-long core of the Triassic strata at PFNP to...

Global warming induced-wildfires of the 21st century reveal the catastrophic effects that widespread biomass burning has on flora and fauna. During mass extinction events, similar wildfire episodes are considered to play an important role in driving perturbations in terrestrial ecosystems. To better evaluate the record of biomass burning and potent...

Triassic strata of the Economy Member of the Wolfville Formation (Newark Supergroup) exposed along the shorelines in Colchester County, Nova Scotia, have yielded an assemblage of continental tetrapods that is clearly different from other Triassic tetrapod communities in eastern North America, including the Late Triassic (Carnian) one from the overl...

High-resolution biomarker and compound-specific isotope distributions, coupled with the degradation of calcareous fossil remnants reveal that intensive euxinia and decalcification (acidification) driven by Central Atlantic Magmatic Province (CAMP) activity formed a two pronged kill mechanism at the end-Triassic mass extinction. In a newly proposed...

The Colorado Plateau Coring Project Phase 1 (CPCP‐1) acquired three continuous drill cores from Petrified Forest National Park (PFNP), Arizona, U.S.A., two of which (CPCP‐PFNP13‐1A and CPCP‐PFNP13‐2B) intersected the Upper Triassic Chinle Formation, Lower(?)‐Middle Triassic Moenkopi Formation (MF) and Permian Coconino Sandstone. We examined both co...

The New England-Québec Igneous Province is considered to be a continental expression of Great Meteor Hotspot magmatism, though other geodynamic scenarios have been suggested. Existing geochronologic data lack the needed accuracy and precision to permit tests of potential causal mechanisms. We provide zircon U-Pb ages for four igneous centers and a...

Nicholas G. McDonand and Bruce Cornet rediscovered the 19th century Davis and Loper fossil fish bed at the Southeastern edge of the Hartford basin in 1969, and began the first of three excavations, with the involvement of Phil Huber a couple years later. A manuscript was written in 2007 on what Cornet and McDonald initially found when they carefull...

Late Triassic records of the orbital pacing of climate are well documented from the stratigraphy of lake basins and marine facies. However, fewer studies have focused on detecting orbital climate signals preserved by fluvial depositional environments, home to terrestrial life. The sedimentary Chinle Formation of the Colorado Plateau (southwestern U...

Significance Hematite provides much of the color for the classic Triassic–Jurassic “red beds” of North America and elsewhere. Measuring the spectrum of visible light reflected and absorbed by the red beds, we demonstrate that the hematite concentrations faithfully track 14.5 million years of Late Triassic monsoonal rainfall over the Colorado Platea...

The nearly 2000 m-thick Ikakern Formation is the basal sedimentary unit in the Argana basin of Morocco, consisting of fluvial red and purple conglomerates in the lower part and interbedded red conglomerates, sandstones, siltstones and mudstones in the upper part. It unconformably overlies deformed and metamorphosed Variscan basement rocks and is un...

Global warming induced-wildfires of the 21st century reveal the catastrophic effects that widespread biomass burning has on flora and fauna. During mass extinction events, similar wildfire episodes are considered to play an important role in driving perturbations in terrestrial ecosystems. To better evaluate the record of biomass burning and potent...

Multiple lines of evidence suggest that volcanic and thermogenic gas emanations from the voluminous eruptions of the Central Atlantic Magmatic Province (CAMP) triggered the end‐Triassic mass extinction. However, a comparison of the timing and duration of the biotic and environmental crises with the timing and duration of the magmatic activity is di...

Significance The end-Triassic mass extinction that occurred ∼202 Ma is one of the “Big Five” biotic crises of the Phanerozoic Eon. It is also accompanied by an organic carbon isotopic excursion that has long been interpreted as the result of a global-scale carbon-cycle disruption. Rather than being due to massive inputs of exogenous light carbon in...

Uranium–lead (U–Pb) geochronology was conducted by laser ablation – inductively coupled plasma mass spectrometry (LA-ICPMS) on 7175 detrital zircon grains from 29 samples from the Coconino Sandstone, Moenkopi Formation, and Chinle Formation. These samples were recovered from ∼ 520 m of drill core that was acquired during the Colorado Plateau Coring...

The Upper Triassic Chinle Formation is a critical non-marine archive of low-paleolatitude biotic and environmental change in southwestern North America. The well-studied and highly fossiliferous Chinle strata at Petrified Forest National Park (PFNP), Arizona, preserve a biotic turnover event recorded by vertebrate and palynomorph fossils, which has...

The Newark Basin is one of the major Mesozoic rift basins along the U.S. Atlantic coast evaluated for carbon dioxide (CO 2 ) storage potential. Its geologic setting offers an opportunity to assess both the traditional reservoir targets, e.g., fluvial sandstones, and less traditional options for CO 2 storage, e.g., mafic intrusions and lavas. Select...

Building on an earlier study that confirmed the stability of the 405‐kyr eccentricity climate cycle and the timing of the Newark‐Hartford astrochronostratigraphic polarity time scale back to 215 Ma, we extend the magnetochronology of the Late Triassic Chinle Formation to its basal unconformity in scientific drill core PFNP‐1A from Petrified Forest...

U-Pb geochronology was conducted by Laser Ablation-Inductively Couple Plasma Mass Spectrometry (LA-ICPMS) on detrital zircon grains from twenty-nine samples from the Coconino Sandstone, Moenkopi Formation, and Chinle Formation. These samples were recovered from ∼520 m of drill core that was acquired during the Colorado Plateau Coring Project (CPCP)...

The Triassic and Jurassic periods have experienced several significant events in Earth history and the parts of the time interval are calibrated by the widely accepted Late Triassic-Early Jurassic Astrochronostratigraphic Polarity Timescale (APTS); mostly based on cores from the Newark Basin Coring Project (NBCP), which lacks in radioisotopic age d...

Significance The Solar System is chaotic, and precise solutions for the motions of the planets are limited to about 60 million years. Using a network of coring experiments that we call the Geological Orrery (after 18th century planetaria), we recover precise and accurate values for the precession of the perihelion of the inner planets from 223- to...

It is widely agreed that the Earth's atmosphere and oceans have undergone major redox changes over the last 2.5 billion years. However, the magnitude of these shifts remains a point of debate because it is difficult to reconstruct concentrations of dissolved O 2 from indirect proxies in sedimentary archives. In this study, we show that an additiona...

Despite the importance of the Triassic Period (ca. 251.9-201.3 Ma) as a time interval of major events in Earth history, to date the period has relatively sparse geochronologic constraints. An interdisciplinary coring experiment, the Colorado Plateau Coring Project (CPCP), was designed to address this with the goal of obtaining both high precision U...

Phase 1 of the Colorado Plateau Coring Project (CPCP-I) recovered a total of over 850 m of stratigraphically overlapping core from three coreholes at two sites in the Early to Middle and Late Triassic age largely fluvial Moenkopi and Chinle formations in Petrified Forest National Park (PFNP), northeastern Arizona, USA. Coring took place during Nove...

Significance Rhythmic climate cycles of various assumed frequencies recorded in sedimentary archives are increasingly used to construct a continuous geologic timescale. However, the age range of valid theoretical orbital solutions is limited to only the past 50 million years. New U–Pb zircon dates from the Chinle Formation tied using magnetostratig...