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Ancient harbours are rich archives of human-environment interaction. However, dating harbour deposits and correlating their stratigraphy is a major challenge because of typically high sedimentation rates over short periods and possible curative dredging events. Portus, the maritime harbour of Rome at the height of the Roman Empire, was a port complex composed of basins and canals connecting the commercial harbour to Rome via the Tiber River. Sediment core CPS1 in the narrowest of these canals, Canale Traverso, is located centrally in what was the capital city's commercial hub and contains a continuous harbour depositional record with average sedimentation rates greater than 1 cm per year. Here we use piston coring, high-resolution core scanning and a multi-proxy sediment analysis including for the first time paleo- and rock-magnetism, and bulk and clay mineralogy in order to overcome the problems of dating harbour deposits and correlating their stratigraphy. The method allowed precise identification of major reworked events, including a dredged deposit and a hyperpycnal deposit, which improve the chronostratigraphy and water depth reconstruction, and sheds light on harbour technologies at the height of the Roman Empire. A debris layer with abundant ceramic fragments and rocks marks the decommissioning of Canale Traverso and provides a new chronostratigraphic marker at Portus. Multi-proxy riverine input signatures point to the possible use of canal gate technology for water flow management.

Ancient harbours are rich archives of human-environment interaction. However, dating harbour deposits and correlating their stratigraphy is a major challenge because of typically high sedimentation rates over short periods and possible curative dredging events. Portus, the maritime harbour of Rome at the height of the Roman Empire, was a port complex composed of basins and canals connecting the commercial harbour to Rome via the Tiber River. Sediment core CPS1 in the narrowest of these canals, Canale Traverso, is located centrally in what was the capital city's commercial hub and contains a continuous harbour depositional record with average sedimentation rates greater than 1 cm per year. Here we use piston coring, high-resolution core scanning and a multi-proxy sediment analysis including for the first time paleo- and rock-magnetism, and bulk and clay mineralogy in order to overcome the problems of dating harbour deposits and correlating their stratigraphy. The method allowed precise identification of major reworked events, including a dredged deposit and a hyperpycnal deposit, which improve the chronostratigraphy and water depth reconstruction, and sheds light on harbour technologies at the height of the Roman Empire. A debris layer with abundant ceramic fragments and rocks marks the decommissioning of Canale Traverso and provides a new chronostratigraphic marker at Portus. Multi-proxy riverine input signatures point to the possible use of canal gate technology for water flow management.

Reconstructing the detailed dietary behaviour of extinct hominins is challenging1-particularly for a species such as Australopithecus africanus, which has a highly variable dental morphology that suggests a broad diet2,3. The dietary responses of extinct hominins to seasonal fluctuations in food availability are poorly understood, and nursing behaviours even less so; most of the direct information currently available has been obtained from high-resolution trace-element geochemical analysis of Homo sapiens (both modern and fossil), Homo neanderthalensis4 and living apes5. Here we apply high-resolution trace-element analysis to two A. africanusspecimens from Sterkfontein Member 4 (South Africa), dated to 2.6-2.1 million years ago. Elemental signals indicate that A. africanus infants predominantly consumed breast milk for the first year after birth. A cyclical elemental pattern observed following the nursing sequence-comparable to the seasonal dietary signal that is seen in contemporary wild primates and other mammals-indicates irregular food availability. These results are supported by isotopic evidence for a geographical range that was dominated by nutritionally depauperate areas. Cyclical accumulation of lithium in A. africanus teeth also corroborates the idea that their range was characterized by fluctuating resources, and that they possessed physiological adaptations to this instability. This study provides insights into the dietary cycles and ecological behaviours of A. africanus in response to food availability, including the potential cyclical resurgence of milk intake during times of nutritional challenge (as observed in modern wild orangutans5). The geochemical findings for these teeth reinforce the unique place of A. africanus in the fossil record, and indicate dietary stress in specimens that date to shortly before the extinction of Australopithecus in South Africa about two million years ago.

Interannual variability of African rainfall impacts local and global communities, but its past behavior and response in future climate projections are poorly understood. This is primarily due to short instrumental records and a lack of long high-resolution palaeoclimate proxy records. Here we present an annually resolved 91,000 year Early Pleistocene record of hydroclimate from the early homininbearing Makapansgat Valley, South Africa. Changes in speleothem annual band thickness are dominated by precession over four consecutive orbital cycles with strong millennial-scale periodicity. The frequency of interannual variability (2.0–6.5 yr oscillations) does not change systematically, yet its amplitude is modulated by the orbital forcing. These long-term characteristics of interannual variability are reproduced with transient climate model simulations of water balance for South Africa from the Late Pleistocene to Recent. Based on these results, we suggest that the frequency of interannual variations in southern African rainfall is likely to be stable under anthropogenic warming, but that the size of year-to-year variations may increase. We see an orbitally forced increase in the amplitude of interannual climate variability between 1.8 Ma and 1.7 Ma coincident with the first evidence for the Acheulean stone tool technology.

Interannual variability of African rainfall impacts local and global communities, but its past behavior and response in future climate projections are poorly understood. This is primarily due to short instrumental records and a lack of long high-resolution palaeoclimate proxy records. Here we present an annually resolved 91,000 year Early Pleistocene record of hydroclimate from the early homininbearing Makapansgat Valley, South Africa. Changes in speleothem annual band thickness are dominated by precession over four consecutive orbital cycles with strong millennial-scale periodicity. The frequency of interannual variability (2.0–6.5 yr oscillations) does not change systematically, yet its amplitude is modulated by the orbital forcing. These long-term characteristics of interannual variability are reproduced with transient climate model simulations of water balance for South Africa from the Late Pleistocene to Recent. Based on these results, we suggest that the frequency of interannual variations in southern African rainfall is likely to be stable under anthropogenic warming, but that the size of year-to-year variations may increase. We see an orbitally forced increase in the amplitude of interannual climate variability between 1.8 Ma and 1.7 Ma coincident with the first evidence for the Acheulean stone tool technology.

Using a conventional, off-the-shelf digital single lens reflex camera and flashes, we were able to create high-resolution panoramas of stratigraphic profiles ranging from a single meter to over 5 m in both height and width at the Middle Stone Age site of PP5-6 at Pinnacle Point, Mossel Bay, South Africa. The final photomosaics are isoluminant, rectilinear, and have a pixel spatial resolution of 1 mm. Furthermore, we systematically color-corrected the raw imagery. This process standardized the colors seen across the photomosaics while also creating reproducible and meaningful colors for relative colorimetric analysis between photomosiacs. Here, we provide a detailed discussion about the creation and application of our photomosaics. In the first part of the paper, we examine the specific characteristics of modern digital single lens reflex (DSLR) cameras and lenses that were important to us in developing our methodology. We also provide a detailed discussion about how to reproduce the methodology in the field and to post-process the imagery. In the final section of the paper, we give several examples to show how we apply our photomosaics within an empirical 3D GIS database. These examples are provided to show how photographic data can be integrated with other digitally-captured data and used to study the relationships between the stratigraphic features seen in the photomosaics and the 3D distribution of excavated archaeological piece-plots, geochronological samples, and other kinds of geological samples.

Using a conventional, off-the-shelf digital single lens reflex camera and flashes, we were able to create high-resolution panoramas of stratigraphic profiles ranging from a single meter to over 5 m in both height and width at the Middle Stone Age site of PP5-6 at Pinnacle Point, Mossel Bay, South Africa. The final photomosaics are isoluminant, rectilinear, and have a pixel spatial resolution of 1 mm. Furthermore, we systematically color-corrected the raw imagery. This process standardized the colors seen across the photomosaics while also creating reproducible and meaningful colors for relative colorimetric analysis between photomosiacs. Here, we provide a detailed discussion about the creation and application of our photomosaics. In the first part of the paper, we examine the specific characteristics of modern digital single lens reflex (DSLR) cameras and lenses that were important to us in developing our methodology. We also provide a detailed discussion about how to reproduce the methodology in the field and to post-process the imagery. In the final section of the paper, we give several examples to show how we apply our photomosaics within an empirical 3D GIS database. These examples are provided to show how photographic data can be integrated with other digitally-captured data and used to study the relationships between the stratigraphic features seen in the photomosaics and the 3D distribution of excavated archaeological piece-plots, geochronological samples, and other kinds of geological samples.

Deposits in sea caves found along the southern coastline of South Africa have produced a rich and detailed archaeological record of early modern humans. There is, however, little evidence for coastal cave deposits and human occupation older than MIS5e (∼120 ka). Based on the correlation of four different chronological methods we present evidence for remnant cave deposits of 1.1–1.0 Ma from the quartzite sea cliff of Pinnacle Point, near Mossel Bay. Initial uranium–thorium ages at isotopic equilibrium indicated an age of >500 ka for two flowstone layers, confirmed by uranium–lead dating of these flowstones from 1.099 ± 0.012 to 1.047 ± 0.011 Ma. TT-OSL (thermally transferred optically stimulated luminescence) provides an age of 1.02 ± 0.088 Ma for the sand grains imbedded in the tufa underlying the flowstone and 0.720 ± 0.066 to 0.665 ± 0.056 for the overlying beach sediments, producing an internally consistent age sequence centring on 1.0–1.1 Ma. The normal palaeomagnetic signal of the younger section of the flowstone is interpreted to represent the Jaramillo between 1.07 and 0.99 Ma. There is a clear hiatus in the middle of this flowstone, leading us to interpret the lower normal signal as the Punaruu event at ∼1.115–1.1051 Ma. Together these four techniques point to an age of 1.1–1.0 Ma for these cave deposits at Pinnacle Point, far older than anticipated. The persistent presence of these 1.1–1.0 Ma deposits means that the enigmatic lack of Earlier Stone Age (Acheulean) artefacts in the sea caves along this coastal region can no longer be explained entirely by the age of the caves or through removal of sediments by previous sea level highstands. We believe that these and other coastal caves from this region, if located high enough above sea level, may contain deposits of great antiquity, which could provide outstanding records of climate, environment, sea level change, and human occupation back into the early to middle Pleistocene.

Deposits in sea caves found along the southern coastline of South Africa have produced a rich and detailed archaeological record of early modern humans. There is, however, little evidence for coastal cave deposits and human occupation older than MIS5e (∼120 ka). Based on the correlation of four different chronological methods we present evidence for remnant cave deposits of 1.1–1.0 Ma from the quartzite sea cliff of Pinnacle Point, near Mossel Bay. Initial uranium–thorium ages at isotopic equilibrium indicated an age of >500 ka for two flowstone layers, confirmed by uranium–lead dating of these flowstones from 1.099 ± 0.012 to 1.047 ± 0.011 Ma. TT-OSL (thermally transferred optically stimulated luminescence) provides an age of 1.02 ± 0.088 Ma for the sand grains imbedded in the tufa underlying the flowstone and 0.720 ± 0.066 to 0.665 ± 0.056 for the overlying beach sediments, producing an internally consistent age sequence centring on 1.0–1.1 Ma. The normal palaeomagnetic signal of the younger section of the flowstone is interpreted to represent the Jaramillo between 1.07 and 0.99 Ma. There is a clear hiatus in the middle of this flowstone, leading us to interpret the lower normal signal as the Punaruu event at ∼1.115–1.1051 Ma. Together these four techniques point to an age of 1.1–1.0 Ma for these cave deposits at Pinnacle Point, far older than anticipated. The persistent presence of these 1.1–1.0 Ma deposits means that the enigmatic lack of Earlier Stone Age (Acheulean) artefacts in the sea caves along this coastal region can no longer be explained entirely by the age of the caves or through removal of sediments by previous sea level highstands. We believe that these and other coastal caves from this region, if located high enough above sea level, may contain deposits of great antiquity, which could provide outstanding records of climate, environment, sea level change, and human occupation back into the early to middle Pleistocene.

Deposits in sea caves found along the southern coastline of South Africa have produced a rich and detailed archaeological record of early modern humans. There is, however, little evidence for coastal cave deposits and human occupation older than MIS5e (∼120 ka). Based on the correlation of four different chronological methods we present evidence for remnant cave deposits of 1.1–1.0 Ma from the quartzite sea cliff of Pinnacle Point, near Mossel Bay. Initial uranium–thorium ages at isotopic equilibrium indicated an age of >500 ka for two flowstone layers, confirmed by uranium–lead dating of these flowstones from 1.099 ± 0.012 to 1.047 ± 0.011 Ma. TT-OSL (thermally transferred optically stimulated luminescence) provides an age of 1.02 ± 0.088 Ma for the sand grains imbedded in the tufa underlying the flowstone and 0.720 ± 0.066 to 0.665 ± 0.056 for the overlying beach sediments, producing an internally consistent age sequence centring on 1.0–1.1 Ma. The normal palaeomagnetic signal of the younger section of the flowstone is interpreted to represent the Jaramillo between 1.07 and 0.99 Ma. There is a clear hiatus in the middle of this flowstone, leading us to interpret the lower normal signal as the Punaruu event at ∼1.115–1.1051 Ma. Together these four techniques point to an age of 1.1–1.0 Ma for these cave deposits at Pinnacle Point, far older than anticipated. The persistent presence of these 1.1–1.0 Ma deposits means that the enigmatic lack of Earlier Stone Age (Acheulean) artefacts in the sea caves along this coastal region can no longer be explained entirely by the age of the caves or through removal of sediments by previous sea level highstands. We believe that these and other coastal caves from this region, if located high enough above sea level, may contain deposits of great antiquity, which could provide outstanding records of climate, environment, sea level change, and human occupation back into the early to middle Pleistocene.

We report the first uranium-series age estimates for rock art in China. Calcite bracketing a paint layer was used to constrain the age of a naturalistic outline hunter-gatherer painting in the Jinsha River area of northwest Yunnan Province (southwest China). The rock paintings in this region are unique in style and content compared with other bodies of rock art in China, which are dominated by Neolithic subject matter. The minimum and maximum ages were determined using isochron techniques on multiple samples of calcite from above and beneath the paint layer. A large painted deer head was dated to between 5738 and 2050 years. This painting and underlying flowstone are superimposed on older paintings that suggest the older paintings are at least 3400 years old, if not older than 5738 years. The results indicate for the first time that Jinsha River rock art is older than other forms of rock art in the region and show that rock art likely extends back to at least the transition from the Palaeolithic to Neolithic in this part of China.

We report the first uranium-series age estimates for rock art in China. Calcite bracketing a paint layer was used to constrain the age of a naturalistic outline hunter-gatherer painting in the Jinsha River area of northwest Yunnan Province (southwest China). The rock paintings in this region are unique in style and content compared with other bodies of rock art in China, which are dominated by Neolithic subject matter. The minimum and maximum ages were determined using isochron techniques on multiple samples of calcite from above and beneath the paint layer. A large painted deer head was dated to between 5738 and 2050 years. This painting and underlying flowstone are superimposed on older paintings that suggest the older paintings are at least 3400 years old, if not older than 5738 years. The results indicate for the first time that Jinsha River rock art is older than other forms of rock art in the region and show that rock art likely extends back to at least the transition from the Palaeolithic to Neolithic in this part of China.

We report the first uranium-series age estimates for rock art in China. Calcite bracketing a paint layer was used to constrain the age of a naturalistic outline hunter-gatherer painting in the Jinsha River area of northwest Yunnan Province (southwest China). The rock paintings in this region are unique in style and content compared with other bodies of rock art in China, which are dominated by Neolithic subject matter. The minimum and maximum ages were determined using isochron techniques on multiple samples of calcite from above and beneath the paint layer. A large painted deer head was dated to between 5738 and 2050 years. This painting and underlying flowstone are superimposed on older paintings that suggest the older paintings are at least 3400 years old, if not older than 5738 years. The results indicate for the first time that Jinsha River rock art is older than other forms of rock art in the region and show that rock art likely extends back to at least the transition from the Palaeolithic to Neolithic in this part of China.

Pinnacle Point Cave 13B (PP13B) has provided the earliest archaeological evidence for the exploitation of marine shellfish, along with very early evidence for use and modification of pigments and the production of bladelets, all dated to approximately 164 ka (Marean et al., 2007). This makes PP13B a key site in studies of the origins of modern humans, one of a handful of sites in Africa dating to Marine Isotope Stage 6 (MIS 6), and the only site on the coast of South Africa with human occupation confidently dated to MIS 6. Along with this MIS 6 occupation there are rich archaeological sediments dated to MIS 5, and together these sediments are differentially preserved in three different areas of the cave. The sediments represent a complex palimpsest of geogenic, biogenic, and anthropogenic input and alteration that are described and interpreted through the use of a variety of macrostratigraphic, micromorphologic, and geochemical techniques. Three independent dating techniques allow us to constrain the age range of these sediments and together provide the stratigraphic context for the analyses of the material that follow in this special issue.

Pinnacle Point Cave 13B (PP13B) has provided the earliest archaeological evidence for the exploitation of marine shellfish, along with very early evidence for use and modification of pigments and the production of bladelets, all dated to approximately 164 ka (Marean et al., 2007). This makes PP13B a key site in studies of the origins of modern humans, one of a handful of sites in Africa dating to Marine Isotope Stage 6 (MIS 6), and the only site on the coast of South Africa with human occupation confidently dated to MIS 6. Along with this MIS 6 occupation there are rich archaeological sediments dated to MIS 5, and together these sediments are differentially preserved in three different areas of the cave. The sediments represent a complex palimpsest of geogenic, biogenic, and anthropogenic input and alteration that are described and interpreted through the use of a variety of macrostratigraphic, micromorphologic, and geochemical techniques. Three independent dating techniques allow us to constrain the age range of these sediments and together provide the stratigraphic context for the analyses of the material that follow in this special issue.