Earth History

Stratigraphy provides insights into the evolution and dynamics of the Earth System over its long history. With recent developments in Earth System science, changes in Earth System dynamics can now be observed directly and projected into the near future. An integration of the two approaches provides powerful insights into the nature and significance of contemporary changes to Earth. From both perspectives, the Earth has been pushed out of the Holocene Epoch by human activities, with the mid-20th century a strong candidate for the start date of the Anthropocene, the proposed new epoch in Earth history. Here we explore two contrasting scenarios for the future of the Anthropocene, recognizing that the Earth System has already undergone a substantial transition away from the Holocene state.
A rapid shift of societies toward the UN Sustainable Development Goals could stabilize the Earth System in a state with more intense interglacial conditions than in the late Quaternary climate regime and with little further biospheric change. In contrast, a continuation of the present Anthropocene trajectory of growing human pressures will likely lead to biotic impoverishment and a much warmer climate with a significant loss of polar ice.contemporary changes to Earth. From both perspectives, the Earth has been pushed out of the Holocene Epoch by human activities, with the mid-20th century a strong candidate for the start date of the Anthropocene, the proposed new epoch in Earth history. Here we explore two contrasting scenarios for the future of the Anthropocene, recognizing that the Earth System has already undergone a substantial transition away from the Holocene state. A rapid shift of societies toward the UN Sustainable Development Goals could stabilize the Earth System in a state with more intense interglacial conditions than in the late Quaternary climate regime and with little further biospheric change. In contrast, a continuation of the present Anthropocene trajectory of growing human pressures will likely lead to biotic impoverishment and a much warmer climate with a significant loss of polar ice.

A range of published arguments against formalizing the Anthropocene as a geological time unit have variously suggested that it is a misleading term of non-stratigraphic origin and usage, is based on in- significant temporal and material stratigraphic content unlike that used to define older geological time units, is focused on observation of human history or speculation about the future rather than geologically significant events, and is driven more by politics than science. In response, we contend that the Anthropocene is a func- tional term that has firm geological grounding in a well-characterized stratigraphic record. This record, al- though often lithologically thin, is laterally extensive, rich in detail and already reflects substantial elapsed (and in part irreversible) change to the Earth System that is comparable to or greater in magnitude than that of previous epoch-scale transitions. The Anthropocene differs from previously defined epochs in reflecting contemporary geological change, which in turn also leads to the term’s use over a wide range of social and political discourse. Nevertheless, that use remains entirely distinct from its demonstrable stratigraphic under- pinning. Here we respond to the arguments opposing the geological validity and utility of the Anthropocene, and submit that a strong case may be made for the Anthropocene to be treated as a formal chronostratigraphic unit and added to the Geological Time Scale.

2014.24 This Atlas of Phanerozoic Upwelling Zones shows the pattern of marine upwelling for 22 time periods from the base of the Cambrian (542 Ma) to the Middle/Late Miocene (Serravallian & Tortonian, 10.5 Ma), plus one additional map for the Neoproterozoic (Middle Ediacaran, 600 Ma). The light blue shading represents areas of upwelling. The blue circles indicate the strength and persistence of the upwelling systems.

These plate tectonic and paleogeographic maps are the work of C. R. Scotese.  The paleoclimate simulations were done by T.L. Moore using the FOAM (Fast Ocean and Atmosphere) Climate Simulation Program. The slight color differences between the symbolson the maps are due to the fact that the maps were made for four separate reports (Scotese et al., 2007; 2008; 2009; & 2011).

There are some notable patterns of upwelling illustrated by the maps.  A strong upwelling system is always present along the Equator and along the west coasts of continents in the southern hemisphere and to a lesser extent along the east coasts of continents in the northern hemisphere.  In addition, moderate zonal upwelling systems are present in temperate latitudes at 45 – 60 degrees (N&S).  Broad regions of oceanic ‘downwelling’, are found in the northern and southern subtropics (23 – 40 degrees, N&S) and in the polar regions. The polar downwelling zones generate cold bottom-water that chills the oceans during times when the Earth has polar icecaps.

The location of ancient upwelling systems is also a good predictor of world-class source rock deposits.  This is especially true for times when continents, covered by shallow seas, cross the Equator. Extremely rich source rock deposits occur along the eastern edge of the Arabian platform because this area was located beneath the Western Tethys Equatorial Upwelling System for nearly 100 million years (mid-Triassic to mid-Cretaceous).  Rich source rock deposits were similarly deposited in Venezuela and Colombia when the vigorous westward moving Equatorial Current crossed the northernmost part of South America (Cretaceous, Maps 27-17).

The maps are from volumes 1-6 of the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2014a,b,c,d). Absolute age assignments are from Gradstein, Ogg & Smith (2008). 

The following maps are included in the Atlas of Phanerozoic Upwelling Zones:

Map 5  Middle/Late Miocene  (Serravallian & Tortonian, 10.5 Ma)
Map 7  Early Miocene (Aquitainian & Burdigalian, 19.5 Ma)
Map 9  Early Oligocene (Rupelian, 31.1 Ma)
Map 12  early Middle Eocene (middle Lutetian, 44.6 Ma)
Map 17  Late Cretaceous (Maastrichtian, 68 Ma)
Map 21  Mid-Cretaceous (Turonian, 91.1 Ma)
Map 23  Early Cretaceous (late Albian, 101.8 Ma)
Map 27  Early Cretaceous (early Aptian, 121.8 Ma)
Map 31  Early Cretaceous (Berriasian, 143 Ma)
Map 35  Late Jurassic (Oxfordian, 158.4 Ma)
Map 39  Early Jurassic (Toarcian, 179.3 Ma)
Map 45  Late Triassic (Carnian, 222.6 Ma)
Map 49  Permo-Triassic Boundary (251 Ma)
Map 54  Early Permian (Artinskian, 280 Ma)
Map 57  Late Pennsylvanian (Gzhelian, 301.2 Ma)
Map 63  Middle Mississippian (early Visean, 341.1 Ma)
Map 65  Late Devonian (latest Famennian, 359.2 Ma)
Map 70  Early Devonian (Emsian, 394.3 Ma)
Map 75  Early Silurian (late Llandovery, 432.1 Ma)
Map 82  Tremadoc (480 Ma)
Map 88  Cambrian – Precambrian Boundary (542 Ma)
Map 90  Late Neoproterozoic (Middle Ediacaran, 600 Ma)


This work should be cited as
Scotese, C.R., and Moore, T.L., 2014.  Atlas of Phanerozoic Upwelling Zones (Mollweide Projection), Volumes 1-6, PALEOMAP Project PaleoAtlas for ArcGIS, PALEOMAP Project, Evanston, IL.


References Cited:

Scotese, C.R., Illich, H., Zumberge, J, and Brown, S., and Moore, T., 2007.  The GANDOLPH Project: Year One Report: Paleogeographic and Paleoclimatic Controls on Hydrocarbon Source Rock Deposition, A Report on the Methods Employed, the Results of the Paleoclimate Simulations (FOAM), and Oils/Source Rock Compilation, Conclusions at the End of Year One: Cenomanian/Turonian (93.5 Ma), Kimmeridgian/Tithonian (151 Ma), Sakmarian/Artinskian (284 Ma), Frasnian/Famennian (375 Ma), February, 2007. GeoMark Research Ltd, Houston, Texas, 142 pp.

Scotese, C.R., Illich, H., Zumberge, J, and Brown, S., and Moore, T., 2008.  The GANDOLPH Project: Year Two Report: Paleogeographic and Paleoclimatic Controls on Hydrocarbon Source Rock Deposition, A Report on the Methods Employed, the Results of the Paleoclimate Simulations (FOAM), and Oils/Source Rock Compilation, Conclusions at the End of Year Two: Miocene (10Ma), Aptian/Albian (120 Ma), Berriasian/Barremian (140 Ma), Late Triassic (220 Ma), and Early Silurian (430 Ma), July, 2008. GeoMark Research Ltd, Houston, Texas, 177 pp.

Scotese, C.R., Illich, H., Zumberge, J, and Brown, S., and Moore, T., 2009.  The GANDOLPH Project: Year Three Report: Paleogeographic and Paleoclimatic Controls on Hydrocarbon Source Rock Deposition, A report on the Results of the Paleogeographic, Paleoclimatic Simulations (FOAM), and Oils/Source Rock Compilation, Conclusions at the End of Year Three: Eocene (45Ma), Early/Middle Jurassic (180 Ma), Mississippian (340 Ma), Neoproterozoic (600 Ma), August 2009. GeoMark Research Ltd, Houston, Texas, 154 pp.

Scotese, C.R., Illich, H., Zumberge, J, and Brown, S., and Moore, T., 2011.  The GANDOLPH Project: Year Four Report: Paleogeographic and Paleoclimatic Controls on Hydrocarbon Source Rock Deposition, A report on the Results of the Paleogeographic, Paleoclimatic Simulations (FOAM), and Oils/Source Rock Compilation, Conclusions at the End of Year Four: Oligocene (30 Ma), Cretaceous/Tertiary (70 Ma), Permian/Triassic (250 Ma), Silurian/Devonian (400 Ma), Cambrian/Ordovician (480 Ma), April, 2011. GeoMark Research Ltd, Houston, Texas, 219 pp.

Scotese, C.R., 2014a, The PALEOMAP Project PaleoAtlas for ArcGIS, version 2, Volume 1, Cenozoic Plate Tectonic, Paleogeographic, and Paleoclimatic Reconstructions,  Maps 1-15, PALEOMAP Project, Evanston, IL.

Scotese, C.R., 2014b, The PALEOMAP Project PaleoAtlas for ArcGIS, version 2, Volume 2, Cretaceous Plate Tectonic, Paleogeographic, and Paleoclimatic Reconstructions,  Maps 16-32, PALEOMAP Project, Evanston, IL.

Scotese, C.R., 2014c, The PALEOMAP Project PaleoAtlas for ArcGIS, version 2, Volume 3, Triassic and Jurassic Plate Tectonic, Paleogeographic, and Paleoclimatic Reconstructions, Map 33-48, PALEOMAP Project, Evanston, IL. 

Scotese, C.R., 2014d, The PALEOMAP Project PaleoAtlas for ArcGIS, version 2, Volume 4, Late Paleozoic Plate Tectonic, Paleogeographic, and Paleoclimatic Reconstructions, Map 49-74, PALEOMAP Project, Evanston, IL.

Scotese, C.R., 2014e, The PALEOMAP Project PaleoAtlas for ArcGIS, version 2, Volume 5, Early Paleozoic Plate Tectonic, Paleogeographic, and Paleoclimatic Reconstructions, Maps 75-88, PALEOMAP Project, Evanston, IL.

Scotese, C.R., 2014f, The PALEOMAP Project PaleoAtlas for ArcGIS, version 2, Volume 6, Precambrian Plate Tectonic, Paleogeographic, and Paleoclimatic Reconstructions, Maps 89-103, PALEOMAP Project, Evanston, IL.

2014.23 This Atlas of Phanerozoic Oceanic Anoxia shows the patterns of oceanic anoxia for 22 time periods from the base of the Cambrian (542 Ma) to the Middle/Late Miocene (Serravallian & Tortonian, 10.5 Ma), plus one additional map for the Neoproterozoic (Middle Ediacaran, 600 Ma). Regions where anoxic conditions may have existed are shown in red.  Regions where well-oxygenated waters occurred are shown in blue. Various shades of green, yellow and orange indicate somewhat dysoxic conditions. Red arrows indicate the direction of surface ocean currents during the summer months (June-July-August).

These plate tectonic and paleogeographic maps are the work of C. R. Scotese.  The paleoclimate simulations were done by T.L. Moore using the FOAM (Fast Ocean and Atmosphere) Climate Simulation Program. The differences in color and symbology from map to map are due to the fact that these figures were originally published in four separate reports (Scotese et al., 2007; 2008; 2009; & 2011).

These estimates of anoxic oceanic conditions have been made by calculating the degree of “restriction” in each sedimentary basin. Restriction is a quantitative estimate of the degree of connection between any marine region and the open ocean. Restriction values ranged from 0 (not restricted) to 100 (very restricted). For example a marine region that is completely surrounded ocean would be classified as “nonrestricted” and would have a restriction value near zero.  On the other hand, a marine embayment that is surrounded mostly by land grid cells would be considered very restricted and would have a high restriction value (>80).

The restriction value was determined by calculating the average distance of each marine grid cell to the nearest land grid cell. Distance measurements were made in 8 compass directions (N,NE,E,SE,S,SW,W,and NW). When the average distance to from each marine grid cell to the nearest land cells was small, it indicated that the marine cell was surrounded by land cells, and hence was “restricted” and likely to be prone to anoxic conditions. Conversely, if the average distance between a marine grid cell and the surrounding land grid cells was very large then it could be inferred that the grid cell was in the “open ocean”, and hence not prone to anoxic conditions. In our approach we use “restriction” as a proxy for oceanic anoxia.

  It should be clear from the above description that this simple method of estimating oceanic anoxia does not take into account any geochemical measurements of anoxia, or bring into play any aspects of ocean dynamics (e.g. upwelling, surface currents or salinity). This approach is purely geographical, and consequently, has a few drawbacks. Firstly, high values of anoxia along ocean-facing coastlines are suspect. Also all of the estimates of oceanic anoxia have been made only for surface waters. In other words, the restriction calculation indicates how well connected the surface waters are to the open ocean but doesn’t say anything about the connectedness of the deeper portions of the basin. An exception is the map of oceanic anoxia for the Permo-Triassic Boundary (Map 49, 251 Ma). In this case, the degree of restriction was calculated for a water depth of 1000m. This was done in order to highlight the degree to which the Paleotethys ocean basin was restricted from the Panthalassic ocean basin. The restriction of deep waters in the Paleotethys may have contributed to the global anoxic oceanic conditions that are thought to have played an important role in the great Permo-Triassic extinction.

A third artifact is sometimes apparent in the maps. Because the restriction calculation were made in only the cardinal compass directions, diagonal streaks are sometimes apparent (e.g. Maps 39 and 45). 

Despite the simple method employed to estimate oceanic anoxia, some obvious patterns emerge from these maps. Ocean basins are most likely to become restricted, and hence anoxic, at two times during their tectonic history: 1) shortly after their initial opening when they are narrow (Maps 21, 27, 31, and 35), and then again 2) when the ocean basin closes, prior to continent-continent collision (Maps 9, 17, 45, 65 and 75). It therefore comes as no surprise that times of widespread oceanic anoxia, such as the mid-Mesozoic oceanic anoxic events (OAEs), are often coincident with times during which numerous, narrow, poorly connected ocean basins are beginning to open or close.

A complimentary set of surface ocean currents for the winter months (December-January-February) are plotted in the Atlas of Phanerozoic Salinity and Ocean Currents. Though similar to the results shown here, there are maps that show opposite flow directions due to monsoonal changes in wind directions. 


The maps are from volumes 1-6 of the PALEOMAP PaleoAtlas for ArcGIS (Scotese, 2014a,b,c,d). Absolute age assignments are from Gradstein, Ogg & Smith (2008). 

The following maps are included in the Atlas of Phanerozoic Oceanic Anoxia:

Map 5  Middle/Late Miocene  (Serravallian & Tortonian, 10.5 Ma)
Map 7  Early Miocene (Aquitainian & Burdigalian, 19.5 Ma)
Map 9  Early Oligocene (Rupelian, 31.1 Ma)
Map 12  early Middle Eocene (middle Lutetian, 44.6 Ma)
Map 17  Late Cretaceous (Maastrichtian, 68 Ma)
Map 21  Mid-Cretaceous (Turonian, 91.1 Ma)
Map 23  Early Cretaceous (late Albian, 101.8 Ma)
Map 27  Early Cretaceous (early Aptian, 121.8 Ma)
Map 31  Early Cretaceous (Berriasian, 143 Ma)
Map 35  Late Jurassic (Oxfordian, 158.4 Ma)
Map 39  Early Jurassic (Toarcian, 179.3 Ma)
Map 45  Late Triassic (Carnian, 222.6 Ma)
Map 49  Permo-Triassic Boundary (251 Ma)
Map 54  Early Permian (Artinskian, 280 Ma)
Map 57  Late Pennsylvanian (Gzhelian, 301.2 Ma)
Map 63  Middle Mississippian (early Visean, 341.1 Ma)
Map 65  Late Devonian (latest Famennian, 359.2 Ma)
Map 70  Early Devonian (Emsian, 394.3 Ma)
Map 75  Early Silurian (late Llandovery, 432.1 Ma)
Map 82  Early Ordovician (Tremadoc, 480 Ma)
Map 88  Cambrian – Precambrian Boundary (542 Ma)
Map 90  Late Neoproterozoic (Middle Ediacaran, 600 Ma)


This work should be cited as
Scotese, C.R., and Moore, T.L., 2014.  Atlas of Phanerozoic Oceanic Anoxia (Mollweide Projection), Volumes 1-6, PALEOMAP Project PaleoAtlas for ArcGIS, PALEOMAP Project, Evanston, IL.


References Cited:

Scotese, C.R., Illich, H., Zumberge, J, and Brown, S., and Moore, T., 2007.  The GANDOLPH Project: Year One Report: Paleogeographic and Paleoclimatic Controls on Hydrocarbon Source Rock Deposition, A Report on the Methods Employed, the Results of the Paleoclimate Simulations (FOAM), and Oils/Source Rock Compilation, Conclusions at the End of Year One: Cenomanian/Turonian (93.5 Ma), Kimmeridgian/Tithonian (151 Ma), Sakmarian/Artinskian (284 Ma), Frasnian/Famennian (375 Ma), February, 2007. GeoMark Research Ltd, Houston, Texas, 142 pp.

Scotese, C.R., Illich, H., Zumberge, J, and Brown, S., and Moore, T., 2008.  The GANDOLPH Project: Year Two Report: Paleogeographic and Paleoclimatic Controls on Hydrocarbon Source Rock Deposition, A Report on the Methods Employed, the Results of the Paleoclimate Simulations (FOAM), and Oils/Source Rock Compilation, Conclusions at the End of Year Two: Miocene (10Ma), Aptian/Albian (120 Ma), Berriasian/Barremian (140 Ma), Late Triassic (220 Ma), and Early Silurian (430 Ma), July, 2008. GeoMark Research Ltd, Houston, Texas, 177 pp.

Scotese, C.R., Illich, H., Zumberge, J, and Brown, S., and Moore, T., 2009.  The GANDOLPH Project: Year Three Report: Paleogeographic and Paleoclimatic Controls on Hydrocarbon Source Rock Deposition, A report on the Results of the Paleogeographic, Paleoclimatic Simulations (FOAM), and Oils/Source Rock Compilation, Conclusions at the End of Year Three: Eocene (45Ma), Early/Middle Jurassic (180 Ma), Mississippian (340 Ma), Neoproterozoic (600 Ma), August 2009. GeoMark Research Ltd, Houston, Texas, 154 pp.

Scotese, C.R., Illich, H., Zumberge, J, and Brown, S., and Moore, T., 2011.  The GANDOLPH Project: Year Four Report: Paleogeographic and Paleoclimatic Controls on Hydrocarbon Source Rock Deposition, A report on the Results of the Paleogeographic, Paleoclimatic Simulations (FOAM), and Oils/Source Rock Compilation, Conclusions at the End of Year Four: Oligocene (30 Ma), Cretaceous/Tertiary (70 Ma), Permian/Triassic (250 Ma), Silurian/Devonian (400 Ma), Cambrian/Ordovician (480 Ma), April, 2011. GeoMark Research Ltd, Houston, Texas, 219 pp.

Scotese, C.R., 2014a, The PALEOMAP Project PaleoAtlas for ArcGIS, version 2, Volume 1, Cenozoic Plate Tectonic, Paleogeographic, and Paleoclimatic Reconstructions,  Maps 1-15, PALEOMAP Project, Evanston, IL.

Scotese, C.R., 2014b, The PALEOMAP Project PaleoAtlas for ArcGIS, version 2, Volume 2, Cretaceous Plate Tectonic, Paleogeographic, and Paleoclimatic Reconstructions,  Maps 16-32, PALEOMAP Project, Evanston, IL.

Scotese, C.R., 2014c, The PALEOMAP Project PaleoAtlas for ArcGIS, version 2, Volume 3, Triassic and Jurassic Plate Tectonic, Paleogeographic, and Paleoclimatic Reconstructions, Map 33-48, PALEOMAP Project, Evanston, IL. 

Scotese, C.R., 2014d, The PALEOMAP Project PaleoAtlas for ArcGIS, version 2, Volume 4, Late Paleozoic Plate Tectonic, Paleogeographic, and Paleoclimatic Reconstructions, Map 49-74, PALEOMAP Project, Evanston, IL.

Scotese, C.R., 2014e, The PALEOMAP Project PaleoAtlas for ArcGIS, version 2, Volume 5, Early Paleozoic Plate Tectonic, Paleogeographic, and Paleoclimatic Reconstructions, Maps 75-88, PALEOMAP Project, Evanston, IL.

Scotese, C.R., 2014f, The PALEOMAP Project PaleoAtlas for ArcGIS, version 2, Volume 6, Precambrian Plate Tectonic, Paleogeographic, and Paleoclimatic Reconstructions, Maps 89-103, PALEOMAP Project, Evanston, IL.

The fossil record provides striking case studies of biodiversity loss and global ecosystem upheaval. Because of this,
many studies have sought to assess the magnitude of the current biodiversity crisis relative to past crises—a task greatly
complicated by the need to extrapolate extinction rates. Here we challenge this approach by showing that the rarity of
previously abundant taxa may be more important than extinction in the cascade of events leading to global changes in
the biosphere. Mass rarity may provide the most robust measure of our current biodiversity crisis relative to those past,
and new insights into the dynamics of mass extinction.

Basin-scale correlations in the subsurface generally rely on lithos- tratigraphic information synthesized from wireline logs, and, in some cases, well cuttings, and cores. However, lithostratigraphic boundaries are often diachronous, and, as such, the correlations based upon them may not provide reliable timelines. In this paper, we use δ13Ccarb data from well cuttings and a core to generate chronostratigraphic logs of Late Ordovician strata spanning the Black River Group, Trenton Group, and Utica Shale across the subsurface of New York State. Although particular δ13Ccarb val- ues may be impacted by (primary) variability in local dissolved inorganic carbon reservoirs and/or (secondary) diagenetic altera- tion, it is possible to identify spatially and stratigraphically coher- ent patterns in δ13Ccarb, which can be used to effectively correlate time-equivalent strata on a basin-wide (or even global) scale, including across lithologies (e.g., between limestone and calcare- ous shale). The present study emphasizes the use of well cuttings, as these are commonly collected during drilling and can provide the maximum lateral resolution for subsurface correlation. Parallel geochemical (percent carbonate and total organic carbon) and isotopic (δ18Ocarb and δ13Corg) data are used to understand the origin of stratigraphic and spatial variability in the δ13Ccarb signal and to identify diagenetic alteration. Stratigraphically coherent δ13Ccarb trends across New York were used to identify six isotopi- cally distinct packages of time-equivalent strata within these for- mations. Pairing chemostratigraphic and lithostratigraphic data improves our ability to document the diachronous nature of lithologic contacts, including the base of the Utica Shale, which is progressively younger moving west through New York.