Misplaced Pages

#591408

77-841: The Klasies River Caves are a series of caves located east of the Klasies River Mouth on the Tsitsikamma coast in the Humansdorp district of Eastern Cape Province , South Africa. The Klasies River Main (KRM) site consists of 3 main caves and 2 shelters located within a cliff on the southern coast of the Eastern Cape. The site provides evidence for developments in stone tool technology, evolution of modern human anatomy and behavior, and changes in paleoecology and climate in Southern Africa based on evidence from plant remains. Klasies River Cave

154-515: A bias towards sites where there is good preservation, skewing results and potentially obscuring the origin of behavioral modernity. Other studies that assert behavioral modernity rely on variables like climate, resource availability, and labor, which also influence behavior. Arguments that state brain size, social demographics and other factors are the cause of behavioral modernity are undermined by these outside variables. Complex behaviors include language and symbolic objects, which are not easily found in

231-647: A country have become erodible. For example, on the Madagascar high central plateau , which constitutes approximately ten percent of that country's land area, most of the land area is devegetated, and gullies have eroded into the underlying soil to form distinctive gulleys called lavakas . These are typically 40 meters (130 ft) wide, 80 meters (260 ft) long and 15 meters (49 ft) deep. Some areas have as many as 150 lavakas/square kilometer, and lavakas may account for 84% of all sediments carried off by rivers. This siltation results in discoloration of rivers to

308-465: A dark red brown color and leads to fish kills. In addition, sedimentation of river basins implies sediment management and siltation costs.The cost of removing an estimated 135 million m of accumulated sediments due to water erosion only is likely exceeding 2.3 billion euro (€) annually in the EU and UK, with large regional differences between countries. Erosion is also an issue in areas of modern farming, where

385-472: A descriptive naming pattern for the observed soils instead of Singer and Wymer's classification system, however both systems are still used today. Sarah Wurz began directing excavations at the site in 2013 and continues today with a continued focus on microstratigraphy; her work is mainly within the Cave 1 Witness Baulk, a section that hadn't been excavated previously. The current work is focused on gathering data from

462-432: A grain, such as pits, fractures, ridges, and scratches. These are most commonly evaluated on quartz grains, because these retain their surface markings for long periods of time. Surface texture varies from polished to frosted, and can reveal the history of transport of the grain; for example, frosted grains are particularly characteristic of aeolian sediments, transported by wind. Evaluation of these features often requires

539-458: A higher density and viscosity . In typical rivers the largest carried sediment is of sand and gravel size, but larger floods can carry cobbles and even boulders . Wind results in the transportation of fine sediment and the formation of sand dune fields and soils from airborne dust. Glaciers carry a wide range of sediment sizes, and deposit it in moraines . The overall balance between sediment in transport and sediment being deposited on

616-827: A higher quality diet which could lead to an evolutionary change in Homo sapiens. Samples taken from hearths within MSA I and Howiesons Poort levels identified parenchyma , heated bones and shellfish found together indicating the cooking of multiple food sources. The parenchyma samples came from underground storage organs, but preservation did not allow for determination of plant species. The abundance of plant species available year-round, as discussed in previous sections, would have provided many reliable energy sources for humans; cooking these starchy plants increases energy absorption. Site occupation patterns based on faunal, food source remains, and lithic evidence suggest that hominins were more mobile during

693-426: A hydrodynamic sorting process within the marine environment leading to a seaward fining of sediment grain size. One cause of high sediment loads is slash and burn and shifting cultivation of tropical forests. When the ground surface is stripped of vegetation and then seared of all living organisms, the upper soils are vulnerable to both wind and water erosion. In a number of regions of the earth, entire sectors of

770-472: A more closed environment while later periods increase in grazing fauna associated with more open environments. This period is associated with MIS 4, a glacial period with cooler temperatures and lower sea levels. Shellfish that appear in tide pools are more common in HP which suggests a further coastline. Data from Pinnacle Point show that the climate during HP was variable and unstable with periods of drought. MSA III

847-495: A mosaic environment that included closed, drier areas with micromammals including moles, and open grasslands that favored grazing ungulates. This period is associated with an interglacial period (MIS 5e) and higher sea levels and warmer temperatures, which is supported by shell middens. MSA II shows a shift from MSA I. This period is associated with MIS 5d-a, with the early part of this phase associated with warmer temperatures shifting towards cooler temperatures later. During this time

SECTION 10

#1732855861592

924-547: A phylogenetic tree. Ancestral and derived traits vary with genetic drift , mutations , and other genetic factors that can steer evolution in many directions. Modern humans ( Homo sapiens ) originated in Africa and trace a lineage back to non-human primate ancestors there. For further discussion on human evolution, see human evolution , evolutionary genetics , and timeline of human evolution . Anatomically modern humans share traits with today's modern Homo sapiens. Remains from

1001-470: A result, can cause exposed sediment to become more susceptible to erosion and delivery to the marine environment during rainfall events. Sediment can negatively affect corals in many ways, such as by physically smothering them, abrading their surfaces, causing corals to expend energy during sediment removal, and causing algal blooms that can ultimately lead to less space on the seafloor where juvenile corals (polyps) can settle. When sediments are introduced into

1078-565: A study found that the use wear did not relate to the same type of musical instrument used at the other MSA sites. Instead, the authors found starchy reside within the teeth of the rasp and suggest that the tool was used for plant processing rather than as an instrument or skin abrader, however this is not proven. A ground bone point dating to 80-65 ka and a charred bone with engraved lines come from Howiesons Poort contexts. Use-wear analysis found longitudinal striations consistent with longitudinal action (including arrow use); microstriations suggest that

1155-588: A total of 281 available edible plant species; these resources were less abundant within the smaller radius and would give reason for an extended foraging journey to acquire varied and less perishable nutrients. A majority of the food plants within these radii can be eaten raw. The association of animal and plant remains with hearths provides evidence that hominins at the site used fire to cook. Bones with cut marks and percussion marks from hammer stones indicate that meat and bone marrow were consumed. Cooked foods provide quickly digestible energy and would have contributed to

1232-541: Is expected to be delivered to the outlet of the river. The sediment transfer and deposition can be modelled with sediment distribution models such as WaTEM/SEDEM. In Europe, according to WaTEM/SEDEM model estimates the Sediment Delivery Ratio is about 15%. Watershed development near coral reefs is a primary cause of sediment-related coral stress. The stripping of natural vegetation in the watershed for development exposes soil to increased wind and rainfall and, as

1309-655: Is located on the border of the Tsitsikamma mountain range on the southeastern coast of Africa. The site sits within the Greater Cape Floristic region, characterized by the fynbos biome; however the Klasies River Cave environment is mixed woods and shrubby brushland and maintains a temperate climate . Klasies River main site is located on a sandstone cliff less than 1 kilometer from the Klasies River mouth and on

1386-467: Is marked by a declining temperatures and receding coastline that would have exposed the Palaeo-Agulhas Plain . The faunal remains are variable and consist of wetland species, open environment grassland grazers, and Cape dune mole rats that prefer sand dunes. This period corresponds to MIS 3, a cooler environment with short warm periods. There is little data available to describe the paleoecology of

1463-581: Is measured on a log base 2 scale, called the "Phi" scale, which classifies particles by size from "colloid" to "boulder". The shape of particles can be defined in terms of three parameters. The form is the overall shape of the particle, with common descriptions being spherical, platy, or rodlike. The roundness is a measure of how sharp grain corners are. This varies from well-rounded grains with smooth corners and edges to poorly rounded grains with sharp corners and edges. Finally, surface texture describes small-scale features such as scratches, pits, or ridges on

1540-502: Is not indicative of higher cognitive function or intelligence. Instead brain size may increase with social learning and increased perceptual and motor abilities. These increased abilities create a positive feedback loop that increases brain size via social learning and its impact on primate and hominin ability to acquire more nutrient rich food sources that favor brain growth. There is a clear relationship between brain size, sociality, and lifespan in primates, but how these influence each other

1617-407: Is not yet certain. Plants within a 12.5 kilometer foraging radius of the caves would have included 161 native species from a mix of geophytes / underground storage organs (USOs), leaves, and fruits, all of which would provide sufficient nutrients for the hominins at the site. By increasing the foraging radius to 35 kilometers away from the site, more nuts, seeds, and grains become available with

SECTION 20

#1732855861592

1694-489: Is passed through generations is argued as symbolic behavior by Sarah Wurz, the current primary investigator at the site. KRM's bone tools represent this symbolic behavior as they exhibit similar modifications and use-wear patterns that suggest they were used and created in the same way. Use of ochre is sometimes interpreted as symbolic behavior, however it also has practical purposes for paint or as an element of an adhesive. At KRM higher concentrations of red ochre are found in

1771-421: Is the highest point in the range at 1675 m. The climate of the range is extremely mild, with temperature variations only between 10 °C and 25 °C generally and rainfall exceeding 1000 mm per annum, thus the region supports verdant fynbos and Afromontane temperate gallery forest habitats. Snow sometimes occurs on the highest peaks in winter. The topography of the mountains is interesting, in that

1848-651: The Khoekhoe language . The Tsitsikamma Range stretches just over 80 km from the Keurbooms River in the west just north of Plettenberg Bay , to Kareedouw Pass and the Eerste River in the east near the town of Kareedouw , and forms a continuous range with the Outeniqua Mountains to the west. The range consists almost exclusively of Table Mountain sandstone which is extremely erosion-resistant. Peak Formosa

1925-491: The Semliki River Valley , dating to around 90 ka, and at Blombos Cave dating to 73 ka. Researchers have also confirmed evidence of shell beads at Klasies River caves, which is corroborated by similar discoveries from other cave sites on the southern coast. The hominins at KRM were hunter-gatherers, and the presence of faunal remains, shellfish, and plant residues shows the wide variety of food sources available near

2002-521: The Howiesons Poort lithics were made from a wider variety of materials and were fashioned into smaller blades and artifacts. Tools from MSA III are made from more non-local raw materials than MSA I or II, but less than Howiesons Poort; these tools from MSA III also have a similar core morphology to Howiesons Poort. The MSA IV lithics consist of more flake blades than observed in MSA III. Earlier layers from

2079-490: The Klasies River Caves site correlates with a MIS stage. The stratigraphy of the site consists of very fine, thin layers of sediment that have compressed under the successive layers on top of them. Researchers have used microstratigraphic techniques to analyze and interpret the complex timeline of sediment deposition and post-depositional activities within the caves. Because the cave system has so many varied layers and

2156-481: The Klasies site appear to have modern human morphology based on cranial traits. The specimens do not have retromolar spaces in the mandible and the supraorbital regions appear similar to other Homo sapiens specimens. The differences in some of the skull fragments are attributed to sexual dimorphism —differences in the size or robustness of the bone between sexes. Other anatomically modern Homo sapiens specimens from

2233-419: The MSA I and Howiesons Poort levels which may be evidence of ritual or symbolic use. Despite the evidence above, modern human behavioral models are still a contested issue. Arguments for origins of behavioral modernity rely on findings of hominin remains at prehistoric sites; this allows material culture and inferred behaviors to be correlated with the discovered remains. However, taphonomic processes produce

2310-463: The MSA I than in MSA II as indicated by use-wear analysis on stone tools and interpretation of shell middens. During the first excavation in 1967 by Singer and Wymer, a coarse sieve was used for screening causing the loss of smaller bones, shells, and other artifacts; because of this sample sized are biased because long bones (i.e. bone shafts) and small bones (i.e. finger bones) were not collected. However,

2387-590: The MSA II dates from 80-28 kya based on Uranium-Thorium and OSL dating within the same layer. This correlates with the Rockfall (RF) Member described by Deacon. Paleoenvironment reconstruction uses multiple analytical foci to help determine a proximate estimate of the climate of a site during a given time frame. These reconstructions are aided through archaeological excavations and finds. Analysis of faunal remains can indicate what species existed across space and time. Likewise, archaeobotanical analysis provides insight into

Klasies River Caves - Misplaced Pages Continue

2464-604: The MSA IV. It does not contain many archaeological features such as hearths or material culture other than lithics. Current ethnobotanical research exploring the biodiversity of Klasies River and the Cape region found that many hunter-gatherer-pastoralists from the Khoi and San populations use the flora and fauna of the region that was also found in archaeobotanical and faunal assemblages. The study took an inventory of plants within 5 km of

2541-776: The MSA are found at sites in East Africa and in the Levant (see Omo Kibish , Mumba Cave , and Shkul Cave ). Researchers have turned to Africa as the birthplace of human behavioral modernity since it is also the place where modern humans evolved. Some researchers have proposed models and trait lists for behavioral modernity that has sparked intense debate among scholars about what constitutes modern human behavior. Evidence of woven grass beds at Border Cave , engraved ochre and beads at Blombos Cave , bone tool culture at Sibudu Cave , and incised ostrich eggshells from Diepkloof rock shelter have all been interpreted as complex behaviors. The debate about

2618-739: The WS member (MIS IV). Only one deciduous tooth is attributable to Howiesons Poort levels (Upper Member). The Upper member (MSA III) contains two parietal fragments, 1 deciduous tooth, and one permanent premolar. The majority of remains came from the SAS member (MSA II) and post-HP included two vertebral fragments, five mandibular fragments, seven teeth without associated alveolar bone, one facial bone, one pelvis fragment, one clavicle, 15 cranial fragments, one radius and one ulna fragment, one manual distal phalanx, and three metatarsals. The LBS Member (MSA I) contained 27 cranial fragments and two mandibular fragments. A majority of

2695-512: The archaeological record; however exchange networks, alliances, and egalitarianism are also indicators of complex behavior. General: Tsitsikamma Mountains The Tsitsikamma mountains form an east-west mountain range located in the Garden Route region of the southern South African coast in the Western Cape and Eastern Cape provinces. Tsitsikamma means 'place of much water' in

2772-402: The authors suggest are more comparable to Holocene Khoesan populations. However, comparisons of prehistoric populations to modern populations are debated and may not have merit. Assessment of relatedness between species is based on ancestral or derived traits to create a phylogeny that assigns closely related specimens to the same or similar groups; this is usually visualized as branches on

2849-596: The bed is given by the Exner equation . This expression states that the rate of increase in bed elevation due to deposition is proportional to the amount of sediment that falls out of the flow. This equation is important in that changes in the power of the flow change the ability of the flow to carry sediment, and this is reflected in the patterns of erosion and deposition observed throughout a stream. This can be localized, and simply due to small obstacles; examples are scour holes behind boulders, where flow accelerates, and deposition on

2926-579: The body of water. Terrigenous material is often supplied by nearby rivers and streams or reworked marine sediment (e.g. sand ). In the mid-ocean, the exoskeletons of dead organisms are primarily responsible for sediment accumulation. Deposited sediments are the source of sedimentary rocks , which can contain fossils of the inhabitants of the body of water that were, upon death, covered by accumulating sediment. Lake bed sediments that have not solidified into rock can be used to determine past climatic conditions. The major areas for deposition of sediments in

3003-425: The bone point was also hafted within a reed, consistent with ethno-historic accounts of early hunter-gatherers from the region. Alternative interprations that include use as a domestic tool for woodworking or as a javelin point are not consistent with microwear of the bone point leading the authors to conclude that the bone tool was used as an arrowhead. Other bone points have been found at MSA sites including Katanda in

3080-473: The bones that were analyzed show anatomical differentiation within Homo sapiens throughout time. Over 50 human remains have been found, a majority of them from Singer and Wymer's original excavation in 1967-68, and a majority of these excavated in Cave 1. The human remains come from early Homo sapiens and the fragments show sexually dimorphic traits . The human remains from KRM are mostly fragmentary adult skeletal elements. No human remains were recovered from

3157-429: The caves. Critiques of the original excavation include sampling bias due to excavation and screening methods, and combination of stratigraphic layers that obscures the sites' complexity; certain strata were lumped together making it difficult to differentiate between activities at the site and combining artifacts and bones from multiple different strata. These initial findings prompted successive excavations to examine

Klasies River Caves - Misplaced Pages Continue

3234-686: The coast of the Indian Ocean. The district receives approximately 500–700 mm (20–28 in) of rainfall annually. The site consists of Caves 1 and 2, and the protected overhangs of Cave 1A and 1B, together known as Klasies River main site. However, Cave 2 was not accessible until later stages after there had been significant deposition and build-up of sediments, and Cave 1B has been under-documented; most finds therefore come from Caves 1 and1A. These caves contain 21 meters of deposits that researchers have struggled to delineate stratigraphically. While sea levels fluctuated over time, during certain occupations,

3311-417: The coastal regions of the ocean, the proportion of land, marine, and organic-derived sediment that characterizes the seafloor near sources of sediment output is altered. In addition, because the source of sediment (i.e., land, ocean, or organically) is often correlated with how coarse or fine sediment grain sizes that characterize an area are on average, grain size distribution of sediment will shift according to

3388-530: The coastline was likely never more than 10 km away from the site. The number of grazers decreased while mixed-feeders and browsers increased; this correlates with a decrease in shrubland and expanding grasslands. Terrestrial fauna include rock hyrax (rock rabbits), brown hyena , Cape dune mole rat , buffalo, equids , and members of the subfamily Alcelaphinae . There is also evidence of forest-dwelling bovid and other animals that prefer wetland grasses and reeds ( African marsh rat and hippopotamus), indicating

3465-413: The cranial bones, hand and foot bones. However, it is likely an error in excavation and collection from Singer and Wymer that has biased against the collection of human remains. An argument for cannibalism has been posed by some researchers. The fragmented human cranial fragments exhibit cut marks and charring similar to that of the faunal remains from the site. This treatment has led to the conclusion that

3542-406: The different caves have different depositional characteristics and sediment properties, it has been hard to create a uniform system to group and chronologically group the layers for a site-wide comparison; natural processes such as erosion, and the influence of people at certain areas of the site (anthropogenic deposition of shell middens , hearths, etc.) have further complicated the interpretation of

3619-422: The edges and corners of particle are. Complex mathematical formulas have been devised for its precise measurement, but these are difficult to apply, and most geologists estimate roundness from comparison charts. Common descriptive terms range from very angular to angular to subangular to subrounded to rounded to very rounded, with increasing degree of roundness. Surface texture describes the small-scale features of

3696-458: The environmental diversity of the site during MSA II. Warm-water shellfish ( brown mussels and other rocky shore species) and cape fur seals were present at the cave as groups were able to exploit marine food sources as well. The Howiesons Poort (HP) environment shifts from the closed environment of the later MSA II into a more open environment featuring more grazing animals. The earlier levels of HP contain more evidence of browsers which indicate

3773-510: The flow. In geography and geology , fluvial sediment processes or fluvial sediment transport are associated with rivers and streams and the deposits and landforms created by sediments. It can result in the formation of ripples and dunes , in fractal -shaped patterns of erosion, in complex patterns of natural river systems, and in the development of floodplains and the occurrence of flash floods . Sediment moved by water can be larger than sediment moved by air because water has both

3850-738: The individuals at Klasies remain the oldest case of hypercementosis in Sub-Saharan Africa (ca. 119 ka). This find is significant because it demonstrates continuity of the condition through the hominin lineage. Finger bones (manual distal phalanges) dating to 90-100 ka were also recovered from the Witness Baulk in Cave 1. These bones are from an adult individual and appear smaller in size than modern human populations; they are also not comparable to Neanderthal phalanges. These phalanges are however similar to phalanges originating in Die Kelders cave which

3927-522: The inhabitants participated in episodic cannibalism . Two individuals appear to be deposited around the same time in one stratigraphic layer, but correlating a site-wide cannibalism event requires a finer-scale understanding of the lithostratigraphy that is not possible at present. Of the remains recovered, two mandibles display the idiopathic dental anomaly of hypercementosis ; this condition has been discovered in Neanderthal and Homo erectus remains, but

SECTION 50

#1732855861592

4004-539: The inside of meander bends. Erosion and deposition can also be regional; erosion can occur due to dam removal and base level fall. Deposition can occur due to dam emplacement that causes the river to pool and deposit its entire load, or due to base level rise. Seas, oceans, and lakes accumulate sediment over time. The sediment can consist of terrigenous material, which originates on land, but may be deposited in either terrestrial, marine, or lacustrine (lake) environments, or of sediments (often biological) originating in

4081-406: The long, intermediate, and short axis lengths of the particle. The form ψ l {\displaystyle \psi _{l}} varies from 1 for a perfectly spherical particle to very small values for a platelike or rodlike particle. An alternate measure was proposed by Sneed and Folk: which, again, varies from 0 to 1 with increasing sphericity. Roundness describes how sharp

4158-435: The marine environment include: One other depositional environment which is a mixture of fluvial and marine is the turbidite system, which is a major source of sediment to the deep sedimentary and abyssal basins as well as the deep oceanic trenches . Any depression in a marine environment where sediments accumulate over time is known as a sediment trap . The null point theory explains how sediment deposition undergoes

4235-655: The microstratigraphy and refining the process of micro-scale excavations. This data allows comparison of KRM to other sites across the continent. The dates of the KRM stratigraphy have been obtained through isotopic analysis and dating of biological materials. Because the site exceeds 50,000 years old, radiocarbon dates are less useful due to carbon contamination. Researchers have resorted to analysis of unstable isotopes, such as Uranium-Thorium (U-Th) to provide more accurate date ranges. Marine isotope stages (MIS) are used to compare large-scale global temporal comparisons; each stage in

4312-405: The microstratigraphy of the site. Deacon excavated units one by one, independently of other units in the cave, recording the stratigraphy observed in each individual unit before grouping units together based on their shared stratigraphic patterns. Rather than use culture stratigraphy, Deacon used a hybrid strategy combining Singer and Wymer's culture stratigraphy and lithostratigraphy . He developed

4389-466: The modern Klasies site and discovered 268 species. Over 50% of these plants were medicinal and 43% were edible or had other uses as demonstrated from interviews with Khoi and San communities. While not all of these plant species may have existed during the Middle Stone Age, these findings still demonstrate the longevity of plant knowledge throughout the communities in the area. The study also noted that

4466-463: The origin of modern human behavior originally began as an assumption that modern anatomy and modern behavior came as a package during the Upper Paleolithic , but the previously discussed evidence situates the debate in the Middle Stone Age as an early adaptation that accrued slowly over time. At Klasies River, the lithic techno-complexes are indicative of symbolic behavior as they change through

4543-430: The plants that were in proximity to the site. These determinations are also aided by global climate estimates provided by deep sea cores. Plant and animal remains can also be indicative of certain climates as species have certain climatic ranges and preferred biomes. Changes in the location of the sea shore and in the grassy or wetland areas surrounding the cave have been determined using these methods. MSA I fauna indicate

4620-545: The proximity to the coast and the surrounding grasslands provided marine life and terrestrial animals that were exploited by the caves inhabitants. From 1967-1968 John Wymer and Ronald Singer conducted excavations that revealed evidence of Middle Stone Age (MSA)-associated human habitation beginning approximately 125,000 years ago. Singer and Wymer excavated Caves 1, 1A and 1B, and part of Cave 2; using culture stratigraphy, they determined stages as MSA I, MSA II, Howiesons Poort, MSA III and MSA IV, which allowed comparison across

4697-513: The range and the ocean also bears the name Tsitsikamma and is characterised by some cattle farms, sparse settlements and dense Afromontane (Temperate) gallery forest. This region sits on a 200m high plateau between the mountains and steep cliffs which drop into the Indian Ocean . Bloukrans Bridge is on the border between the Eastern and Western Cape provinces, and sports the highest bungee jump in

SECTION 60

#1732855861592

4774-479: The range rises abruptly from the south at a very defined line that runs almost due east-west at the 34° south latitude. This is due to the very regular nature of the rise of the Table Mountain Sandstone in an anticline fold structure above the grade of the surrounding Tsitsikamma coastal plateau. The Tsitsikamma National Park lies just to the south of the range on the Indian Ocean . The region between

4851-491: The relative input of land (typically fine), marine (typically coarse), and organically-derived (variable with age) sediment. These alterations in marine sediment characterize the amount of sediment suspended in the water column at any given time and sediment-related coral stress. In July 2020, marine biologists reported that aerobic microorganisms (mainly), in " quasi-suspended animation ", were found in organically-poor sediments, up to 101.5 million years old, 250 feet below

4928-548: The remains are cranial fragments, and these outnumber the post-cranial elements. This pattern has been argued to represent a pattern that is also observed in the faunal remains record. One argument proposes that the preferred elements are taken to the site and are preserved due to fragmentation from marrow collection e.g. the cranial bones are the preferred bones. Another argument suggests a collection bias in which post-cranial long bones were preferred and were not preserved because they were destroyed during marrow collection leaving only

5005-473: The removal of native vegetation for the cultivation and harvesting of a single type of crop has left the soil unsupported. Many of these regions are near rivers and drainages. Loss of soil due to erosion removes useful farmland, adds to sediment loads, and can help transport anthropogenic fertilizers into the river system, which leads to eutrophication . The Sediment Delivery Ratio (SDR) is fraction of gross erosion (interill, rill, gully and stream erosion) that

5082-479: The sequence from MSA I through MSA III. Each sequence displays a different social convention for construction of stone tools (a techno-complex) that isn't based on raw material availability. However, Howiesons Poort is the only recognized techno-complex at Klasies River Caves because it is recognized as a techno-complex across Southern Africa; further studies may recognize techno-complexes from other culture-stratigraphies as well. Conventionalized artifact manufacture that

5159-443: The site dating to MIS 5d-e have a density of shellfish and debitage from stone tool production. This dense accumulation of animal remains, shell middens, and the remains from stone tool production indicate that the caves were used as a home base rather than an intermittent shelter during this period. At later times in the younger strata of the site, a higher density of stone tools and lower density of shellfish at later dates suggest that

5236-793: The site on this basis with the lowest level being Basal Gravels, followed by the Light Brown Sand (LBS) Member, the Rubble Brown Sand (RBS) member, the Shell and Sand (SAS) member, the Rockfall (RF) and Upper member, and the White Sand (WS) member. Some of these layers are then further subdivided. This system allows researchers to compare deposition patterns and contexts across the site in each cave which may have different dates because of differing deposition processes in each cave environment; some caves may not contain each member listed. MIS 3 *in Cave 1A,

5313-543: The site was only used as a tool production site rather than a residential location. This change in mobility at KRM corresponds to a similar change during the same time period at Pinnacle Point . Bone tools have been found at KRM during the original excavations by Singer and Wymer coming from MSA II and Howiesons Poort strata. Three denticulated bone tools originating from an MSA II context resemble musical rasps found at other Middle Stone Age sites in Southern Africa. The bone rasps were fashioned out of bovid rib and long bone, but

5390-464: The site. Food consumption at the site consisted of marine and terrestrial animals, evidenced by shell middens and faunal remains of bovids. Scientists suggest that the wide availability and variation in food sources were the cause for the anatomically modern humans due to the nutrients required for larger brains and cognitive function. However other research on the relationship between brain size, longevity and social learning suggests that large brain size

5467-400: The stratigraphy. A lithostratigraphic and culture stratigraphic approach are both used at KRM today. Singer and Wymer's stages at KRM began at the base, MSA I, followed by MSA II, Howiesons Poort, MSA III, and MSA IV. These groupings are based on changes on stratigraphy and/or changes in material culture though time. Deacon chose to organize the site based on soil descriptions; he categorizes

5544-445: The surface of the grain. Form (also called sphericity ) is determined by measuring the size of the particle on its major axes. William C. Krumbein proposed formulas for converting these numbers to a single measure of form, such as where D L {\displaystyle D_{L}} , D I {\displaystyle D_{I}} , and D S {\displaystyle D_{S}} are

5621-494: The use of a scanning electron microscope . Composition of sediment can be measured in terms of: This leads to an ambiguity in which clay can be used as both a size-range and a composition (see clay minerals ). Sediment is transported based on the strength of the flow that carries it and its own size, volume, density, and shape. Stronger flows will increase the lift and drag on the particle, causing it to rise, while larger or denser particles will be more likely to fall through

5698-422: The use of certain plant types for survival during climate changes , and proposed that humans in the past could have subsisted in similar ways. There is evidence for stone tool production at the site. Rounded quartzite cobbles appear to be the preferred material for stone tool production based on the recovery of raw materials at the site. Analysis of flakes and debitage indicate that free hand stone percussion

5775-577: The varied and complex stratigraphy . Hilary Deacon began work in Caves 1, 1A and 1B from 1984-1995 focusing on the arbitrary delineation (the "Witness Baulk") that Singer and Wymer used to differentiate Cave 1A from Cave 1, as these caves are actually continuous. While the Singer and Wymer excavation used units that were excavated uniformly across the cave layer by layer, successive excavations focused on different stratigraphic approaches. Deacon's excavations maintained

5852-590: The world. Sediment Sediments are most often transported by water ( fluvial processes ), but also wind ( aeolian processes ) and glaciers . Beach sands and river channel deposits are examples of fluvial transport and deposition , though sediment also often settles out of slow-moving or standing water in lakes and oceans. Desert sand dunes and loess are examples of aeolian transport and deposition. Glacial moraine deposits and till are ice-transported sediments. Sediment can be classified based on its grain size , grain shape, and composition. Sediment size

5929-451: Was the primary method of tool production at Cave 1, and the prevalence of consistent and nearly uniform points suggest that these tools were the desired end product. Lithic artifacts do show variation through the various occupation stages of KRM. Howiesons Poort interrupts the relative uniformity seen in MSA I and MSA II: in the latter, large and long quartzite points and blades were the goal end products and were usually not retouched , while

#591408