In response to our definition of the Anthropocene as a geological event analogous to the Great Oxidation Event and other complex, transformative events in the geological record (Gibbard et al., 2022a, 2022b), Waters et al. (2022) offers a suite of detailed and novel terminology for the Anthropocene with little or no previous support in the geological literature. The term “event” is already widely used as a general term in geology. We maintain that the Anthropocene is best understood through this general definition as a complex, heterogenous and ongoing event composed of manifold identifiable events occurring within it.

Over the course of the last decade the concept of the Anthropocene has become widely established within and beyond the geoscientific literature but its boundaries remain undefined. Formal definition of the Anthropocene as a chronostratigraphical series and geochronological epoch following the Holocene, at a fixed horizon and with a precise global start date, has been proposed, but fails to account for the diachronic nature of human impacts on global environmental systems during the late Quaternary. By contrast, defining the Anthropocene as an ongoing geological event more closely reflects the reality of both historical and ongoing human–environment interactions, encapsulating spatial and temporal heterogeneity, as well as diverse social and environmental processes that characterize anthropogenic global changes. Thus, an Anthropocene Event incorporates a substantially wider range of anthropogenic environmental and cultural effects, while at the same time applying more readily in different academic contexts than would be the case with a rigidly defined Anthropocene Series/Epoch.

The Anthropocene has yet to be defined in a way that is functional both to the international geological commu-nity and to the broader fields of environmental and social sciences. Formally defining the Anthropocene as a chro-nostratigraphical series and geochronological epoch with a precise global start date would drastically reduce the Anthropocene's utility across disciplines. Instead, we propose the Anthropocene be defined as a geological event, thereby facilitating a robust geological definition linked with a scholarly framework more useful to and congruent with the many disciplines engaging with human-environment interactions. Unlike formal epochal definitions, geologi-cal events can recognize the spatial and temporal hetero-geneity and diverse social and environmental processes that interact to produce anthropogenic global environ-mental changes. Consequently, an Anthropocene Event would incorporate a far broader range of transformative human cultural practices and would be more readily applicable across academic fields than an Anthropocene Epoch, while still enabling a robust stratigraphic characterization.

U.S. Geological Survey, Florence Bascom Geoscience Center, Reston, VA, USA Department of Anthropology, Stanford University, Stanford, CA, USA School of Archaeology and Ancient History, University of Leicester, Leicester, UK Department of Geography and Environmental Systems, University of Maryland, Baltimore County, Baltimore, MD, USA Department of Geological Sciences, California State University, Long Beach, CA, USA Scott Polar Research Institute, University of Cambridge, Cambridge, UK Climate Change Institute and School of Biology and Ecology, University of Maine, Orono, ME, USA Department of Geography, University College London, London, UK Natural History Museum of Denmark, University of Copenhagen, København K, Denmark Department of Earth and Environment, Franklin and Marshall College, Lancaster, PA, USA Department of Environmental Sciences, University of Virginia, Charlottesville, VA, USA Department of Geography and Earth Sciences, Aberystwyth University, Aberystwyth, Wales, UK Faculty of Humanities and Performing Arts, University of Wales Trinity Saint David, Lampeter, Wales, UK

This study explores the use of cash incentives towards positive behaviour change amongst adolescents at different schools in the Khomas Region, Windhoek, Namibia. The aim of the research was to assess the efficacy of the Reducing HIV/AIDS in Adolescents (RHIVA) programme’s cash incentive-based theory of change. The hypothesis of the model is that cash incentives can promote positive behavioural change. The behaviour change is related to HIV/AIDS prevention and other behavioural patterns more specific to adolescents. The study used secondary data from a pre-post quasi-experimental research design collected between 2013 and 2015. The primary data came from 529 responses to a baseline survey and 458 responses to an end-line survey conducted in the Khomas Region. The secondary analysis explored the impact of cash incentives on learners’ sexual behaviour, especially the learners who received full RHIVA intervention (IG2). The study concludes that the full RHIVA programme intervention resulted in a 10% reduction in sexual activity. The RHIVA programme is effective for learners younger than 16 years and for females from middle to high-income areas. However, the study found that cash incentives do not result in an increase in the number of times that learners were tested for HIV. It also found that direct cash payments to learners have the potential to be both a deterrent and an incentive for positive behaviour change as direct cash payments are prone to other socio-structural pressures such as the prevalence of alcohol and drug use at school and community levels. The study further concludes that conditional cash transfers remain very important in increasing the HIV Counselling and Testing (HCT) uptake of learners despite certain limitations.

At the 75th Annual Meeting of the North American Commission on Stratigraphic Nomenclature, 22 October, 2020, in connection with GSA 2020 Connects Online, the Commission voted unanimously to accept the revision of Articles 73, 81 and 82 of the North American Stratigraphic Code (North American Commission on Stratigraphic Nomenclature, 2005 with subsequent updates), and concomitant changes to Table 2; specific revisions of the Code are indicated in red color. These replace all older versions of the specified Articles. An application for this revision (Aubry et al. 2019) was published in Stratigraphy more than one year prior to the meeting; thus, the vote on this application for revision follows Article 21 of the Code.

First posted January 6, 2020 For additional information, contact: Florence Bascom Geoscience CenterU.S. Geological Survey926A National Center12201 Sunrise Valley DriveReston, VA 20192 The Atlantic Coastal Plain, the southeasternmost physiographic province in the United States, is underlain by strata that regionally dip gently eastward and gradually thicken toward the Atlantic Ocean basin. These strata, ranging in age from Middle Jurassic to Holocene, accumulated along the eastern margin of North America after the break-up of the supercontinent Pangaea during the Early Jurassic. In the east-central United States north of Florida, Cape Hatteras is the point of land that most closely approaches the eastern edge of the Atlantic Continental Shelf of the United States. In 1946, Esso (now part of ExxonMobil) drilled a deep oil exploration well to basement rock near the Cape Hatteras lighthouse. No oil or gas was found there, or in any of the other test wells that were drilled within the onshore North Carolina Coastal Plain. Recent work indicates that the top of the oil window lies at 9,000 feet near the base of the Cape Hatteras Esso #1 test well. Therefore, any mature petroleum source rocks that may be present in the North Carolina Coastal Plain are only likely to be found east of the present coastline.Although the Cape Hatteras test well did not produce oil or gas, it did produce a wealth of stratigraphic information about the outer portion of the onshore Atlantic Continental Shelf. Advances in global stratigraphic correlation, in tandem with our analyses of calcareous nannofossils and dinoflagellate cysts (dinocysts) from the Cape Hatteras test-well spot samples have produced significant advances beyond earlier interpretations of this well and other deep test wells inshore of Cape Hatteras. These results, when coupled with work done offshore of Cape Hatteras, have allowed us to create a more detailed cross section of the North Carolina Coastal Plain and adjacent continental shelf than previously possible.

First posted March 28, 2019 For additional information, contact: Florence Bascom Geoscience CenterU.S. Geological Survey926A National Center12201 Sunrise Valley DriveReston, VA This publication portrays the geology of the Hardeeville NW quadrangle and parts of the Brighton and Pineland quadrangles that are within Jasper County, South Carolina. The study area is located in the Atlantic Coastal Plain province, approximately 50 to 70 kilometers (km) inland from the coast. The data are compiled from geological field mapping, light detection and ranging (lidar) elevation data, cores, optically stimulated luminescence ages, radiocarbon ages, and biostratigraphic interpretations. Most of the study area is occupied by the valley of the Savannah River, and exposures of geologic units are very limited. Traditional geologic mapping in this area is difficult because of limited access, subdued topography, extensive swamps, and abundant vegetation.The Savannah River flows predominantly southeast, and forms most of the border between the States of South Carolina and Georgia. The river is approximately 483 km long and has a total drainage area of approximately 15,850 square km. Although upstream tributaries drain the southeastern side of the Appalachian Blue Ridge province, the Savannah River begins in the Piedmont province and then flows across the Atlantic Coastal Plain province to the Atlantic Ocean. For much of its extent, the modern channel of the Savannah River is located on the southwestern side of the river valley, and the southwestern bank of the valley is the active cut bank. Within the study area, the valley of the Savannah River trends southeast and is relatively straight. The valley has relatively low relief, although the southwestern valley wall is steeper and has greater relief than the northeastern valley wall.Elevations within the valley mostly range from 3 to 15 meters (m) above sea level, whereas elevations on the high terrace that forms the eastern margin of the Savannah River valley are 15 to 20 m above sea level. The width of the valley is 6 to 7 km in the northern part of the study area and expands to 10 to 12 km farther south. The modern river channel occupies the southwestern side of the valley, and some modern (active) creeks enter the river from the west. Sand hills and low-relief terraces are present to the east of the modern river channel, and the eastern side of the valley is characterized by abandoned meandering and linear channels. Fan-shaped deposits of sand and mud are present where relict (inactive) channels enter the eastern side of the valley. Abandoned meandering channels of low relief (<3 m) are also present to the east on the high terrace (>15 m elevation) that forms the eastern margin of the Savannah River valley. Within the study area, most of the Savannah River valley is covered by alluvial wetland community vegetation dominated by cypress and tupelo trees, although sand hills within the valley are covered by xeric sand community vegetation dominated by pine trees.

The Washington East 1:100,000 quadrangle stretches from the eastern part of Washington, D.C., to the western part of the Delmarva Peninsula. About 2 km2 in the far northwestern corner is mapped as the metasedimentary Laurel Formation of the Piedmont. The remaining 99.96% is within the Coastal Plain: the western half is a dissected plateau with exposures from Cretaceous to Miocene; the eastern half includes the Chesapeake Bay and low, estuarine, bay-facing terraces. Fluvial gravel underlies muted uplands of Delmarva. Two buried Mesozoic basins, trending northeast, underlie parts of the map area. Newly exposed mammal-dominated tracks near the north-central margin of the map area are from the youngest Potomac Group, thus, Late Cretaceous. Football fans will note that latest Cretaceous and Paleocene sediments underlie FedEx Field. Paleontologists worldwide flock to the Calvert Cliffs, spectacular Miocene exposures along the western shore of the Bay, to find shark teeth and macro- and microfossils. Successively younger Quaternary terrace deposits step down to the rivers and the Bay, recording sea-level highstands. New evidence from cores and geophysics documents a complex network of paleochannels during lowstands and allows nuanced interpretation of Quaternary history in general and of the Bay in particular. For our mapping, LiDAR has been transformational, permitting the identification of features such as marine scarps; windblown dunefields; and elliptical, raised-rim, shallow basins. Combining LiDAR with field observations has allowed new insights on freeze-thaw processes and deposits. The area is more structurally complex than previously thought; high-angle Coastal Plain faults are related at depth to Mesozoic rift basin margins. Recent assessments indicate potential for undiscovered natural gas reserves in these buried basins. Paleochannels from ancestral Hudson/Delaware, Susquehanna and Potomac Rivers are locally dominated by sands and gravel, easily mined, resulting in landfill sites. Although most of the islands within the Chesapeake Bay are losing land area, Poplar Island is an example of artificial fill and an engineered wildlife sanctuary; it is being rebuilt using material dredged near Baltimore. Not fun, but valuable to know, is that the Eocene Marlboro Clay is susceptible to landslides.

The late Eocene Chesapeake Bay impact structure was formed in a multilayered target of seawater underlain sequentially by a sediment layer and a rock layer in a continental-shelf environment. Impact effects in the “brim” (annular trough) surrounding and adjacent to the transient crater, between the transient crater rim and the outer margin, primarily were limited to the target-sediment layer. Analysis of published and new lithostratigraphic, biostratigraphic, sedimentologic, petrologic, and mineralogic studies of three core holes, and published studies of a fourth core hole, provided information for the interpretation of the impact processes, their interactions and relative timing, their resulting products, and sedimentation in the brim. Most studies of marine impact-crater materials have focused on those found in the central crater. There are relatively few large, complex marine craters, of which most display a wide brim around the central crater. However, most have been studied using minimal data sets. The large number of core holes and seismic profi les available for study of the Chesapeake Bay impact structure presents a special opportunity for research. The physical and chronologic records supplied by study of the sediment and rock cores of the Chesapeake Bay impact indicate that the effects of the initial, short-lived contact and compression and excavation stages of the impact event primarily were limited to the transient crater. Only secondary effects of these processes are evident in the brim. The preserved record of the brim was created primarily in the subsequent modifi cation stage. *E-mails: henning.dypvik@geo.uio.no; ggohn@usgs.gov; leedward@usgs.gov; whorton@usgs.gov; dspowars@usgs.gov; rlitwin@usgs.gov. These authors are listed alphabetically. Dypvik, H., Gohn, G.S., Edwards, L.E., Horton, J.W., Jr., Powars, D.S., and Litwin, R.J., 2018, Chesapeake Bay Impact Structure—Development of “Brim” Sedimentation in a Multilayered Marine Target: Geological Society of America Special Paper 537, p. 1–68, https://doi.org/10.1130/2018.2537. © 2018 The Authors. Gold Open Access: This paper is published under the terms of the CC-BY license and is available open access on www.gsapubs.org. OPEN ACCESS GO LD Downloaded from https://pubs.geoscienceworld.org/books/chapter-pdf/4591573/spe537-01.pdf by Universitetet I Oslo user on 06 February 2019

The Fall Line (formally "Tidewater Fall Line") separates the more resistant igneous, metamorphic, and consolidated sedimentary rocks of the Piedmont from the typically unconsolidated deposits of the Coastal Plain of Virginia. Widespread but now discontinuous patches of a deeply weathered sand and gravel are found west of the Fall Line, capping the highest hilltops. Near the community of Midlothian, Virginia, the gravels are underlain by fine-grained marine silts that bear an informative assemblage of fossil dinoflagellate cysts (dinocysts). In situ dinocysts belong to middle Miocene zone DN7, which is calibrated to similar to 12-13 Ma. These deposits are assigned to the upper part of the Choptank Formation, which crops out similar to 25 km(15 mi) to the east at an elevation similar to 60m(200 ft) lower. The dinocyst assemblage suggests that the maximum extent of this Choptank transgression probably covered a significant expanse of the Virginia Piedmont. The Choptank marine silts constrain the age of the unconformably overlying Midlothian gravels to younger than the latter part of the middle Miocene. Previous work has indicated that these gravels also are older than the Pliocene Yorktown Formation. Rare, reworked dinocysts in these Choptank outcrops west of the Fall Line are sourced from older deposits of more than one age. The source could be older updip strata of the lower Eocene Nanjemoy Formation, now erosionally removed. Alternatively, the source could be material referable to the upper Eocene Exmore Formation that resulted from the Chesapeake Bay impact event.

We describe an outcrop of the Cretaceous–Paleogene (K–Pg) boundary exposed due to construction near New Albany, Union County, Mississippi. It consists of the Owl Creek Formation and overlying Clayton Formation. The Owl Creek Formation is rich in the ammonites Discoscaphites iris and Eubaculites carinatus, which, along with biostratigraphically important dinoflagellate cysts and calcareous nannofossils, indicate deposition occurred within the last 1 million years, most likely last 500 kyrs, of the Cretaceous. The base of the overlying Clayton Formation marks the K–Pg boundary, and consists of a 15-30 cm thick muddy, poorly sorted quartz sand containing abundant spherules representing ejecta derived from the Chicxulub impact event. Impact spherules range in size from 0.5 mm to 1 mm in diameter and are hollow and well preserved, with details such as smaller vesicular spherules enclosed within. The spherules are altered to clay minerals such as smectite and are typical of those found at K–Pg boundary sites in the Gulf of Mexico and beyond. Spherules are scattered throughout the bed, and surface counts suggest an average of 4 spherules per cm2. Macrofossils within the spherule bed represent a rich fauna of ammonites, benthic molluscs (bivalves and gastropods), echinoids, as well as crabs and sharks. Macrofossil preservation ranges from whole to fragmentary, with most fossils preserved as internal moulds. The infill of the fossils is lithologically identical to the matrix of the spherule bed, including impact ejecta preserved within phragmocones and body chambers of ammonites, and differs from the underlying Owl Creek Formation. This suggests that the animals were either alive or loosely scattered on the sea floor at the time of deposition. Grain size changes indicate multiple events were responsible for deposition, and together with taphonomic evidence are consistent with dynamic high energy post-impact processes. Later sea level change during the Paleocene is responsible for a sharp contact at the top of the spherule bed. Geochemical evidence from the Owl Creek and Clayton Formations at this locality indicate numerous local paleoenvironmental changes affected the Mississippi Embayment at the time of the K–Pg boundary and mass extinction event.

Consistency in stratigraphic nomenclature enables communication among scientists both regionally and globally, thus requiring the North American Stratigraphic Code, as presented by the North American Commission on Stratigraphic Nomenclature, to follow international convention. The ratification of three subseries of the Holocene by the International Union of Geological Sciences (IUGS) in June 2018 warrants the integration of subseries among formal chronostratigraphic ranks in the Code. The purpose of making subseries a formal rank is that it aligns the Code with the International Stratigraphic Guide, and establishes the option of using the prefixes super- and sub- for other chronostratigraphic and geochronologic ranks. This is in accordance with the guiding principle of the Code to make it as consistent as possible with international usage and to foster innovations to meet the expanding and changing needs of earth scientists.

The Paleocene-Eocene Thermal Maximum (PETM) was an interval of extreme warmth that caused disruption of marine and terrestrial ecosystems on a global scale. Here we examine the sediments, flora, and fauna from an expanded section at Mattawoman Creek-Billingsley Road (MCBR) in Maryland and explore the impact of warming at a nearshore shallow marine (30-100m water depth) site in the Salisbury Embayment. Observations indicate that at the onset of the PETM, the site abruptly shifted from an open marine to prodelta setting with increased terrestrial and fresh water input. Changes in microfossil biota suggest stratification of the water column and low-oxygen bottom water conditions in the earliest Eocene. Formation of authigenic carbonate through microbial diagenesis produced an unusually large bulk carbon isotope shift, while the magnitude of the corresponding signal from benthic foraminifera is similar to that at other marine sites. This proves that the landward increase in the magnitude of the carbon isotope excursion measured in bulk sediment is not due to a near instantaneous release of C-12-enriched CO2. We conclude that the MCBR site records nearshore marine response to global climate change that can be used as an analog for modern coastal response to global warming.