Blombos Cave is an archaeological site located in Blombos Private Nature Reserve, about 300 km east of Cape Town on the Southern Cape coastline in South Africa. The cave contains Middle Stone Age (MSA) deposits currently dated to between about 100,000 and 70,000 years Before Present (BP), and a Late Stone Age sequence dated to between 2,000 and 300 years BP. The cave site was first excavated in 1991, and field work has been conducted there regularly since 1997, continuing to the present.
The excavations at Blombos Cave have provided important new information about the behavioral evolution of anatomically modern humans. The archaeological record from this site has been central to the debate about the cognitive and cultural origins of early humans and to the current understanding of when and where key behavioral innovations appeared among Homo sapiens in southern Africa during the Late Pleistocene. Archaeological materials and faunal remains from the Middle Stone Age phase in Blombos Cave—dated to about 100,000–70,000 years BP—are considered to show greater ecological adaptation, a wider range of subsistence strategies, use of multi-step technology, creation of composite tools, stylistic elaboration, increased economic and social organization, and evidence of symbolic behavior.
The most informative materials found at Blombos Cave include engraved ochre, engraved bone ochre processing kits, marine shell beads, refined bone and stone tools, and a wide variety of terrestrial and marine faunal remains, such as shellfish, birds, tortoises, ostrich eggshells, and mammals of different sizes. These findings, along with later re-analyses and excavations of other Middle Stone Age sites in southern Africa, have changed the way scientists understand when and where modern human behavior developed.
On 29 May 2015, Heritage Western Cape officially protected the site as a provincial heritage site.
Cross-hatching drawn in ochre on a stone fragment found at Blombos Cave is believed to be the earliest known drawing made by a human.
Excavation history and research context
Blombos Cave was first studied in 1991–1992 as part of Professor Christopher S. Henshilwood’s (1995) doctoral research at the University of Cambridge. The research focused on Holocene archaeology in the coastal Garcia State Forest, southern Cape, South Africa. Blombos Cave was one of nine Holocene Later Stone Age sites examined during this time and was initially called GSF8 (Garcia State Forest, site no. 8). In 1997, the site was renamed Blombos Cave and given the acronym BBC. Between 1999 and 2011, ten field seasons, each lasting six weeks, were conducted at the cave.
The Blombos Cave project began with the early 1990s excavations and introduced new research methods to study southern African prehistory. Initially, Professor Henshilwood’s research focused on the more recent Later Stone Age layers. However, since 1997, the project has concentrated on the Middle Stone Age layers. Over time, the project grew from a small local study into a large, international archaeological effort with advanced technology.
From 2010–2015, Blombos Cave was the main site for the TRACSYMBOLS research program. This multi-disciplinary project involved Professor Christopher S. Henshilwood from the University of Bergen, Norway, and the University of the Witwatersrand, South Africa, as well as Professor Francesco d'Errico from the University of Bordeaux 1, France. The goal was to study how important behavioral changes developed in Homo sapiens and Homo neanderthalensis in southern Africa and Europe, and to examine if environmental changes influenced these developments between 180,000 and 25,000 years ago. This was done by combining archaeological findings, environmental data, and climate models from both continents.
Since 2017, the cave has been studied by many of the same researchers under the Centre for Early Sapiens Behaviour (SapienCE) at the University of Bergen, Norway. The centre works with universities in South Africa, the United Kingdom, France, Germany, and Norway. The project aims to use a broader, multi-disciplinary approach, including studies in cognitive science, neuroscience, geoscience, climate modeling, and animal remains, over a 10-year period.
Site description
The cave is located on a south-facing cliff 34.5 meters above sea level, approximately 100 meters from the current shoreline. It is formed in calcretes of the Wankoe Formation, and the geological evidence suggests the cave was created by wave action during the Plio-Pleistocene period.
Inside Blombos Cave, there is one main chamber. The accessible floor of the cave is about 39 meters behind the drip line. To the west of the main chamber, human-made deposits extend inward 3–5 meters. However, the cave ceiling in this area is low, reaching the same level as the surface, which blocks access to the deposits below. North-east of the main chamber, the deposits spread into a low, sand-filled ante-chamber of unknown size. By the end of the 2011 field season, 19.5 meters of the cave’s interior had been excavated.
The outer talus of the cave forms a gently sloping platform about 23 meters wide, extending 4–5 meters southward before dropping sharply toward the shoreline, which is 34.5 meters below the cave entrance. The talus includes Middle Stone Age deposits, rock fall, and loose sediments, stabilized by large exposed rock blocks (14 meters in size). These blocks fell from the cliff above during a time between prehistoric use of the site, preventing erosion and allowing sediments to build up near the drip line.
Water rich in calcium carbonate (CaCO₃) seeps from the cave roof and flows through the sediments, creating an alkaline environment that helps preserve materials. The excavated Middle Stone Age deposits include wind-blown sand from the entrance and pieces of rock falling from the ceiling. Mixed within the sand are broken remains of marine and land animals (such as fish, shells, eggshells, and bones) and organic material. Large fire pits, small round hearths, and layers of burned material are found throughout the entire Middle Stone Age layer.
Stratigraphy and dating
In 1992, when scientists began digging at Blombos Cave, the entrance was partly blocked by sand from nearby dunes. A layer of sand about 20 cm thick, which had not been disturbed by humans, covered the older layers of the cave. Below this sand, researchers found seven main layers of occupation in the 2.5 to 3 meter deep cave. Three of these layers belong to the Later Stone Age (L1–L3), and four belong to the Middle Stone Age (M1, Upper M2, Lower M2, and M3). These layers are further divided into smaller, thin sections, most less than 10 cm thick. The Later Stone Age and Middle Stone Age layers are separated by a thick, undisturbed layer of yellow sand called the "Hiatus" or "DUN." This sand entered the cave around 68,000 to 70,000 years ago and shows little disturbance from the layers above it.
Humans lived in Blombos Cave briefly and occasionally during the Middle Stone Age (101,000–70,000 years ago) and in the later parts of the Later Stone Age (2,000–300 years ago). A long period with no human activity between about 68,000 and 2,000 years ago, along with geological evidence, suggests the cave was blocked by sand during this time. The cave entrance likely reopened during the mid-Holocene (about 4,000–3,000 years ago), when rising sea levels eroded the dune. Remnants of this dune can still be seen in the surrounding area.
The Later Stone Age layers have been dated to 2000–290 years ago using radiocarbon dating. The Middle Stone Age layers are dated to about 101,000–70,000 years ago using methods such as thermoluminescence (TL), optically stimulated luminescence (OSL), uranium-thorium series (U/Th), and electron spin resonance (ESR). The lowest layers of the M3 phase are older than 130,000 years, but the sediments below these layers have not been dated (as of June 2013).
The Hiatus layer (DUN), made of undisturbed sand above the M1 phase, is dated to 69,000 ± 5,000 and 70,000 ± 5,000 years ago using OSL. The upper part of the M1 phase, linked to the Still Bay tool-making tradition, is dated to 74,900 ± 4,300 to 72,500 ± 4,600 years ago. Jacobs et al. (2013) suggest the Still Bay period at Blombos Cave began after 75,500 years ago and ended 67,800 years ago, lasting no more than 6,600 years. However, the true age of the Still Bay has been debated, and some researchers have questioned the methods used to determine these dates.
The lower layers of the M2 phase (layers CG, CGAA, CGAB, CGAC) are dated to 78,900 ± 5,900 to 78,800 ± 5,600 years ago. The upper layers of the M3 phase are dated to about 100,000 years ago, matching a period of high sea levels during Marine Isotope Stage (MIS) 5c. The lowest M3 layers are older than 130,000 years.
In 2013, some scientists raised concerns about the accuracy of the Middle Stone Age timeline established by Jacobs et al. (2008), citing errors in how luminescence data was handled and how uncertainties were estimated. However, the timeline based on OSL dating at Blombos Cave remains consistent with results from other methods (TL, ESR, U/Th) and has not been challenged.
Archaeological remains and material culture from the Middle Stone Age levels
The most detailed and largest collection of Still Bay points in southern Africa comes from the Still Bay sequence in Blombos Cave. Still Bay points are the key features of the Still Bay techno-complex, and they are stone tools shaped on both sides, often called "lance-heads," "laurel leaf-shaped," or "willow leaf-shaped" points. These tools have retouched sides, are elliptical or lance-shaped, and usually have two pointed ends.
Since excavations began at Blombos Cave, more than 500 points or fragments have been found, with 352 described in detail. The main material used for making Still Bay points in Blombos Cave is silcrete (72%), followed by quartzite (15%) and quartz (13%). Quartzite and quartz are easily found near the cave, but the source of silcrete is unknown. It may come from areas like Riversdale or Albertinia, about 30 km away, or from underwater sources. About 90% of the Still Bay points found in Blombos Cave are classified as "production rejects," meaning they were not completed. Studies of stone tools from the 'CC' unit suggest that most of the stone waste came from making bifacial points. Villa et al. (2009:458) concluded that Blombos Cave was a workshop where making points was a major activity.
The process of making Still Bay points is divided into four steps. Hard hammer and direct percussion were used in the first step, followed by soft hammer and marginal percussion in the second. Pressure flaking was used only in the final step, and some points were later modified with hard hammer percussion. Still Bay points from Blombos Cave are among the earliest examples of pressure flaking, a technique more common in later periods. Experiments and microscopic studies show that some silcrete stones were heated before pressure flaking, which improved their quality for shaping.
Some researchers believe the bifacial points were attached to spears or used as knives. Others suggest the careful shaping of the points may indicate social or stylistic traditions during the Middle Stone Age. These points might have had symbolic meanings, such as marking identity or being used in social exchanges. Högberg and Larsson (2011) proposed that unfinished Still Bay points were left behind in Hollow Rock Shelter, possibly for later use or to show solidarity with other groups.
In 2011, archaeologists found a small rock fragment with red lines among spear points and other materials. After seven years of testing, scientists confirmed the lines were made with an ochre crayon from 73,000 years ago. This is the oldest known abstract rock drawing. The geometric patterns are an example of early creative behavior. Researchers in Nature called the find "a prime indicator of modern cognition" and noted that early humans used an ochre crayon to draw on stone.
Archaeologist Christopher Henshilwood, who led the study, said the lines stopping abruptly at the edges suggest the pattern originally covered a larger area.
Ochre, an iron-rich mineral, is commonly found at Stone Age sites in southern Africa, including Blombos Cave. Over 8,000 pieces of ochre-like material have been found in Blombos Cave, with more than 1,500 being 10 mm or longer. Many show signs of use, such as engraving or incising, and may represent early abstract or symbolic designs.
In 2002, two finely engraved ochre pieces from the Still Bay units were reported in Science Magazine. These pieces had cross-hatched patterns and parallel lines. In 2009, six more engraved ochre pieces were found, dating to between 70,000 and 100,000 years ago. Similar designs were also found on a bone fragment from Blombos Cave. Engraved ochre has also been found at other sites, such as Klein Kliphuis, Wonderwerk Cave, and Klasies River Cave 1. These pieces, along with engraved ostrich eggshells from Diepkloof, are considered some of the earliest examples of abstract representation and symbolic traditions.
Geometric designs are often linked to modern human behavior and complex thinking. While abstract art in Europe is well-documented after 40,000 years ago, evidence from Blombos Cave and other sites in southern Africa shows such designs existed at least 30,000 years earlier. This suggests that symbolic traditions and artistic styles were common in southern Africa 70,000–100,000 years ago.
The engraved ochre pieces found in Blombos Cave and other sites indicate that conventional symbols were used over time and across regions. Soft ochre could have been turned into red paint for body or cave painting. Shell beads and bone tools found with ochre support the idea that early humans were interested in decoration.
However, recent studies suggest ochre may have had practical uses as well, such as in making mastic, protecting skin from the sun or insects, as soft hammers for shaping stone, preserving hides, or as medicine.
In 2008, archaeologists discovered an ochre processing workshop in Blombos Cave dating to 100,000 years ago. Analysis showed a liquid mixture rich in pigment was made and stored in abalone shells. The workshop included ochre, bone, charcoal, grindstones, and hammer stones. The toolkits were left in place, and dune sand from outside the cave later preserved them before the area was used again, possibly decades or centuries later.
The exact use of the compound remains unclear.
Palaeoenvironment
Scientists study past environmental changes by looking at time periods called marine oxygen isotope stages, or MIS. These stages are determined by analyzing oxygen isotope signals in tiny sea creatures called planktonic foraminifera found in ocean sediment layers. The climate changes recorded from MIS 6 to MIS 3 cover the time when early humans in southern Africa used tools and behaviors associated with the Middle Stone Age (MSA). These stages are especially important for understanding this period. In archaeology, environmental clues come from many sources, including small animal remains, large animal bones, ancient plant pollen, sand dunes, and cave formations. Recently, researchers have focused more on understanding the environments where MSA people lived and how they adapted. This is because behaviors like making tools, finding food, using pigments, and moving across landscapes are being connected to changes in climate and environment.
Linking MSA lifestyles to environmental conditions is challenging. Some scientists believe major climate shifts influenced social changes, but others disagree. The debate is also complicated by the many different types of climate clues, which can be interpreted in different ways depending on where and when they are studied. Current research has two main goals: first, to improve the accuracy of dating methods, such as radiocarbon, uranium-series, and luminescence, to better understand when events happened. Second, to refine the database of environmental clues so that unclear or conflicting interpretations can be reviewed as new evidence is found. Two important studies have been conducted: Jacobs and Roberts, who examined dates from the Still Bay and Howiesons Poort periods across southern Africa, and Chase, who studied environmental conditions during MIS 4 and how climate changes affected this time. Current evidence suggests that the Still Bay and Howiesons Poort periods occurred during relatively wet conditions. However, it is still unclear what the environmental conditions were during earlier parts of the MSA (MSA I, II, III, and MSA 2), which are broadly linked to MIS 6 and MIS 5 (b, c, d, e). These earlier periods have not been studied in detail.
Provincial Heritage Site
Blombos Cave was named a provincial heritage site by Heritage Western Cape on May 29, 2015, under Section 27 of the National Heritage Resources Act. This designation gives the site Grade II status and ensures it is protected by South African heritage laws.
In 2015, the South African government asked to add the cave to the World Heritage Sites list. The cave has been placed on the tentative list as part of a potential future group nomination, along with Pinnacle Point, Sibudu Cave, Klasies River Caves, Border Cave, and Diepkloof Rock Shelter.