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Sight and blindness: The relationship between ostracod eyes, water depth, and light availability in the Arctic Ocean

Eye loss has been a long-standing interest in evolutionary biology. Many organisms that inhabit environments without light penetration, for example the deep sea, exhibit eye loss and thus become blind. However, water-depth distribution of eyes in marine organisms is poorly understood. Ostracods are widely distributed crustaceans, and many sighted marine ostracods have eye tubercles (lenses) on the
Jingwen Zhang, Moriaki Yasuhara, Chih-Lin Wei, Skye Yunshu Tian, Kyawt K. T. Aye, Laura Gemery, Thomas M. Cronin, Peter Frenzel, David J. Horne

Evaluating an improved systems approach to wetland crediting: Consideration of wetland ecosystem services

The Chesapeake Bay Agreement (CBA) has numerous direct goals for improving habitat, living resources, and water quality, conserving lands, engaging communities and addressing a changing climate. To date, the progress toward the wetlands outcome (creation/ restoration of 85,000 acres and enhancement of 150,000 acres) has been very slow and the outcome is projected to be off course for 2025. Two spe
Pamela Mason, Gregory B. Noe, Alicia Berlin, Denise Clearwater, Sally Claggett, Dave Goerman, Brooke J. Landry, Alison Santoro

Paleoenvironmental and paleoecological dynamics of the U.S. Atlantic Coastal Plain prior to and during the Paleocene-Eocene Thermal Maximum

We studied the rapid paleo-environmental changes and the corresponding biotic responses of benthic foraminifera of a shallow shelf site during the late Paleocene and the Paleocene-Eocene Thermal Maximum (PETM). The PETM is globally characterized by a negative δ13C excursion in marine and terrestrial sediments. Isotope data from the Atlantic Coastal Plain from the South Dover Bridge core, Maryland,
Monika Doubrawa, Peter Stassen, Marci M. Robinson, Robert P. Speijer

Benthic foraminiferal community changes across the Miocene climatic optimum Identified by SHEBI analysis (SHE analysis for biozone identification), Calvert Cliffs, Maryland, USA

The Calvert Cliffs, MD, an iconic section of Middle Miocene strata, have been well studied both paleontologically and stratigraphically for over a century. However, few studies of the Calvert Cliffs have looked at the benthic foraminifera. This study uses SHEBI analysis (SHE analysis for biozone identification) of benthic foraminiferal assemblages to analyze community change in the Calvert and Cho
Seth R. Sutton, Stephen J. Culver, Lee-Ann Hayek, David J. Mallinson, Marci M. Robinson, Harry J. Dowsett, Martin A. Buzas

Paleogene Earth perturbations in the US Atlantic Coastal Plain (PEP-US): Coring transects of hyperthermals to understand past carbon injections and ecosystem responses

The release of over 4500 Gt (gigatonnes) of carbon at the Paleocene–Eocene boundary provides the closest geological analog to modern anthropogenic CO2 emissions. The cause(s) of and responses to the resulting Paleocene–Eocene Thermal Maximum (PETM) and attendant carbon isotopic excursion (CIE) remain enigmatic and intriguing despite over 30 years of intense study. CIE records from the deep sea are
Marci M. Robinson, Kenneth Miller, Tali Babila, Tim J Bralower, Jim Browning, Marlow Cramwinckel, Monika Doubrawa, Gavin L Foster, Megan Fung, Sean D. Kinney, Maria Makarova, Pete McLaughlin, Paul Pearson, Ursula Rohl, Morgan Schaller, Jean Self-Trail, Appy Sluijs, Thomas Westerhold, James R. Wright, James Zachos

What the cliffs near America’s earliest settlements tell us about climate change

Climate change is a big problem for natural habitats, people, and the systems that support society, including roads, water supply, electrical grids, and phone and internet connections. It’s an important theme in politics, economics, and culture. Scientists make computer models to show what the climate might be like in the future, and it looks very different from what we are used to. Scientists can
Harry J. Dowsett, Marci M. Robinson

Cathodoluminescence differentiates sedimentary organic matter types

High-resolution scanning electron microscopy (SEM) visualization of sedimentary organic matter is widely utilized in the geosciences for evaluating microscale rock properties relevant to depositional environment, diagenesis, and the processes of fluid generation, transport, and storage. However, despite thousands of studies which have incorporated SEM methods, the inability of SEM to differentiate
Paul C. Hackley, Ryan J. McAleer, Aaron M. Jubb, Brett J. Valentine, Justin E. Birdwell

Revisiting the physical processes controlling the tropical atmospheric circulation changes during the Mid-Piacenzian Warm Period

The Mid-Piacenzian Warm Period (MPWP; 3.0–3.3 Ma), a warm geological period about three million years ago, has been deemed as a good past analog for understanding the current and future climate change. Based on 12 climate model outputs from Pliocene Model Intercomparison Project Phase 2 (PlioMIP2), we investigate tropical atmospheric circulation (TAC) changes under the warm MPWP and associated und
Ke Zhang, Yong Sun, Xuan Zhang, Christian Stepanek, Ran Feng, Daniel Hill, Gerrit Lohmann, Aisling M Dolan, Alan M Haywood, Ayako Abe-Ouchi, Bette Otto-Bliesner, Camille Contoux, Deepak Chandan, Gilles Ramstein, Harry J. Dowsett, Julia C. Tindall, Michiel Baatsen, Ning Tan, William Richard Peltier, Qiang Liu, Wing-Le Chan, Xin Wang, Xu Zhang

Deformation-induced graphitization and muscovite recrystallization in a ductile fault zone

A suite of slate samples collected along a 2 km transect crossing the Lishan fault in central Taiwan were evaluated to assess the role of ductile deformation in natural graphitization at lower greenschist facies metamorphic conditions. The process of natural aromatization, or graphitization, of an organic precursor is well established as a thermally driven process; however, experimental studies ha
Martha (Rebecca) Stokes, Aaron M. Jubb, Ryan J. McAleer, David Bish, Robert Wintsch

Morphotypical and geochemical variations of planktic foraminiferal species in Siberian and Central Arctic Ocean core tops

In this work, we utilize a transect of core top, mid- to late Holocene, sediments from the Eastern Siberian Sea to the central Arctic Ocean, spanning gradients in upper-ocean water column properties, to examine regional planktic foraminiferal species abundances and geochemistry. We present species- and morphotype-specific foraminiferal assemblages at these sites and stable isotope analyses of neog
Maya Prabhakar, Kaustubh Thirumalai, Thomas M. Cronin, Laura Gemery, Elizabeth Thomas, Patrick Rafter

Saltwater intrusion and sea level rise threatens U.S. rural coastal landscapes and communities

The United States (U.S.) coastal plain is subject to rising sea levels, land subsidence, more severe coastal storms, and more intense droughts. These changes lead to inputs of marine salts into freshwater-dependent coastal systems, creating saltwater intrusion. The penetration of salinity into the coastal interior is exacerbated by groundwater extraction and the high density of agricultural canals
Kiera O'Donnell, Emily S. Bernhardt, Xi Yang, Ryan Emanuel, Marcelo Ardon, Manuel Lerdau, Alex Manda, Anna Braswell, Todd BenDor, Eric Edwards, Elizabeth Frankenberg, Ashley Helton, John Kominoski, Amy Lesen, Lindsay Naylor, Gregory B. Noe, Kate Tully, Elliott White, Justin Wright

Polar paleoenvironmental perspectives on modern climate change

In today’s rapidly changing climate, society needs a better understanding of climate impacts on sea level, ice sheets and glaciers, sea ice, ocean circulation, ecosystems, biodiversity, and other aspects of planet Earth. Paleoenvironmental records provide a unique and invaluable source of insight into these complex issues, and place recent observations into a broader historical context. This essay
Laura Gemery, Adrián López-Quirós