The Middle of the Earth, one of the twelve divisions of the globe, encompasses Africa down to its subcontinent, the lands and seas of the Mediterranean Basin and the Red Sea, the Canary Islands, and the Cape Verde Islands.

The northwestern boundary extends from south-central Germany along the Swiss border, encompassing all Swiss cities except Basel. It then separates southern France from northern France, continues through Spain, and divides Portugal at Setúbal, marking a north-south division within both countries. The boundary then extends into the Atlantic Ocean, where it distinguishes Madeira (a Portuguese territory) from the Canary Islands (ruled by Spain).

The northeastern boundary separates Alpine Austria from the rest of the country, then moves through the Balkans, roughly following the borders between:

• Hungary and Slovenia,
• Serbia and Croatia,
• Bosnia and Herzegovina, Montenegro, and Kosovo,
• Bulgaria and North Macedonia,
• Turkey-in-Europe and Greece.

From there, the line continues through western Turkey and Cyprus, dividing Syria and most of Lebanon from Israel and most of Jordan, and marking the separation between western and eastern Arabia.

The southeastern boundary follows the historic division between North and South Yemen, then extends through eastern Africa, delineating Mozambique from Zambia.

South Atlantic (49,293 – 28,578 BCE): Upper Pleistocene I — Gyre Worlds, Glacial Winds, and the Dual Ocean of Life

Geographic and Environmental Context

The South Atlantic World in the late Ice Age consisted of two great subregions divided by climate and current:

1. Northern South Atlantic — the warm, subtropical to equatorial half of the basin, centered on the South Atlantic Gyre between Africa and Brazil.
   It included St Helena and Ascension Island on the Mid-Atlantic Ridge, along with smaller seamounts and reefs scattered between the African and South American coasts.
   The Brazilian ridge-islands of Fernando de Noronha, Trindade, and Martim Vaz, though oceanic in origin, belong properly to South America Major rather than this subregion.

2. Southern South Atlantic — a cold, subantarctic crescent of Tristan da Cunha, Gough, Bouvet, South Georgia, the South Sandwich Islands, and the South Orkneys, swept by the Antarctic Circumpolar Current (ACC).

Together these domains—one bathed in tropical gyres, the other lashed by polar seas—formed a single oceanic system linking Africa, South America, and Antarctica through currents, winds, and migrating life.

Climate and Environmental Shifts

This epoch saw the intensification of the Last Glacial Maximum.

• Sea Level: 60–90 m lower than today, broadening continental shelves but leaving the steep volcanic islands largely unchanged.

• Atmosphere: Stronger trade winds spun the northern gyre; circumpolar westerlies sharpened into persistent gales in the south.

• Temperature: The northern basin cooled modestly but remained tropical; the southern rim dropped far below freezing in winter, with seasonal sea ice pushing northward.

• Ocean Circulation: The strengthened Benguela upwelling off southwest Africa and the cold-return limb of the ACC enriched planktonic productivity across both subregions.

The South Atlantic thus operated as a thermal bridge—drawing heat northward and nutrients southward.

Ecosystems and Biotic Communities

Northern South Atlantic

• Islands: St Helena and Ascension were barren volcanic cones with thin soils, patchy grasses, and a few endemic shrubs.

• Marine Life: Coral reefs persisted in warm pockets; tuna, billfish, and turtles patrolled gyre margins; seabirds nested on cliffs devoid of land predators.

• Connections: Trade-wind drift and dust from the Sahara fertilized the sea surface, sustaining modest plankton blooms.

Southern South Atlantic

• Islands: Volcanic or glaciated, from ice-bound Bouvet and South Georgia to the green, cloud-fed uplands of Tristan and Gough.

• Fauna: Albatrosses, petrels, penguins, and seals crowded beaches and ridges; krill and fish filled the surrounding seas; whales migrated seasonally to feed.

• Vegetation: Mosses, lichens, and cushion plants clung to ice-free patches; on Tristan and Gough, grasses and peat expanded in sheltered hollows.

Across both subregions, ecosystems were entirely pre-human but highly productive, their nutrient loops linking equator to ice edge.

Technology and Material Culture

Human societies elsewhere in the world—Africa, Europe, and Asia—were mastering blade technologies, tailored clothing, and cave art, yet none had crossed the Atlantic.
The South Atlantic remained wholly unvisited, its distances and storms forming an impassable frontier.
Had mariners somehow reached it, survival would have demanded cold-weather craft, insulated gear, and marine-mammal exploitation far beyond contemporary capacity.

Movement and Interaction Corridors

Without people, currents and wildlife defined movement:

• The South Equatorial Current carried surface waters westward toward Brazil, returning via the Benguela Current up the African coast.

• The ACC circled eastward around the subantarctic islands, binding the southern oceans into one ecosystem.

• Migratory species—whales, seals, turtles, and seabirds—traced these routes, forming a living chain that connected polar and tropical worlds.

These same pathways would later shape human navigation and global trade, but in this age, they belonged wholly to the non-human biosphere.

Cultural and Symbolic Dimensions

The South Atlantic existed outside the human imagination.
Its islands, uncharted and unseen, bore only natural symbols—the cyclical return of whales and seabirds, the pulse of storms, and the sculpting of glaciers and lava.
Elsewhere, humans painted caves and buried their dead in ochre; here, the ocean itself was the artist, carving coastlines and layering guano into the first living soils.

Environmental Adaptation and Resilience

• Northern gyre ecosystems adapted to cooler conditions with flexible plankton communities and resilient coral refugia.

• Southern subantarctic systems tracked glacial rhythms: vegetation retreated under ice and recolonized rapidly when temperatures rose; animal colonies shifted breeding sites as sea ice expanded and contracted.
  Despite climatic volatility, the basin’s food webs remained stable, proving that biological resilience thrives on movement and interconnection.

Transition Toward the Glacial Maximum

By 28,578 BCE, the South Atlantic stood in full glacial balance:

• The Northern South Atlantic rotated as a warm, slow gyre feeding Africa and Brazil with moisture and marine life.

• The Southern South Atlantic thundered with westerlies and icy spray, a crucible of upwelling and migration.

No humans yet sailed its waters, yet its two subregions already functioned as distinct worlds—one subtropical, one subantarctic—each more closely tied to distant hemispheric partners than to each other.
When seafarers finally ventured across it tens of millennia later, they would find not an empty sea, but a living engine that had been shaping climates, currents, and ecological continuity since long before human time began.

Northern South Atlantic (49,293–28,578 BCE): Volcanic Oases in a Cooler Ocean

Geographic & Environmental Context

The subregion of Northern South Atlantic includes Saint Helena and Ascension Island. These mid-ocean volcanoes rose steeply from abyssal plains: Ascension, a young shield with cinder cones and lava fields; Saint Helena, an older, deeply eroded massif ringed by cliffs. Narrow boulder/cobble strands, sea caves, and wave-cut benches framed their coasts; inland, stark basalt and trachyte ridges held patchy soils and crater basins.

Climate & Environmental Shifts

This was peak Last Glacial time. Sea level stood ~60–90 m lower, widening shore platforms and exposing additional benches. Cooler sea-surface temperatures and stronger southeast trade winds intensified upwelling along the eastern basin (Benguela limb) and invigorated the South Equatorial Current. Rainfall was limited; fog and orographic cloud banks wetted windward slopes episodically. Dust delivery from Africa waxed, seeding open-ocean productivity.

Subsistence & Settlement

No humans reached these islands. Ecologies were oceanic: immense seabird rookeries on ledges and cinder cones; green and hawksbill turtles foraged offshore and likely nested on low strands during interludes; intertidal zones teemed with grazers and filter feeders. Inland vegetation was sparse—ferns, lichens, and pioneering grasses colonized ash and scoria, with moisture-catching ravines sheltering a few shrub pockets.

Technology & Material Culture

Globally, Upper Paleolithic blade and bone technologies blossomed; none touched this oceanic pair. The only “materials” on island surfaces were volcanic rock, bird bone, shell, guano crusts, and wind-blown sand.

Movement & Interaction Corridors

The South Atlantic subtropical gyre (Brazil → South Equatorial → Guinea → Canary → North Brazil Currents) and trade-wind belts routed pelagic life. Seabirds commuted across basins; turtles navigated gyre margins; tunas, billfish, and sharks hunted frontal zones.

Cultural & Symbolic Expressions

None locally. If the islands “spoke,” it was through biogenic landmarks—white guano veneers on headlands and turtle crawls etched into storm-lowered beaches.

Environmental Adaptation & Resilience

Seabirds nested in dense, shifting colonies; pioneering plants stabilized ash with rhizo-mats; turtle nesting tracked strands that came and went with sea-level oscillation. Nutrient subsidies (guano → soils) catalyzed small green oases on otherwise austere rock.

Transition

By 28,578 BCE, glacial seas and trade winds still ruled. The islands stood as stark, lifeboat habitats in a cool, windier Atlantic, rich offshore, austere on land—entirely unknown to humans.

Northern South Atlantic (28557 – 7822 BCE): Gyre Heart, Volcanic Isles, and Oligotrophic Blue

Geographic and Oceanographic Frame

Northern South Atlantic here means the South Atlantic basin from the Equator to the mid-subtropics, centered on the South Equatorial Current and the subtropical gyre core. It includes the isolated volcanic and reef systems of Ascension and St Helena (on the Mid-Atlantic Ridge) and, on the western flank, Fernando de Noronha, Rocas Atoll, São Pedro & São Paulo, and Trindade–Martim Vaz off Brazil.
(Note: the Tristan–Gough group lies farther south in the Southern South Atlantic.)

Climate Pulses and Sea-Level Change

• Last Glacial Maximum (c. 26,500 – 19,000 BCE): Global sea level ~120 m lower expanded rocky shore platforms around the islands; cooler SSTs and stronger trade winds intensified Benguela upwelling along southwest Africa and sharpened nutrient fronts. Coral accretion slowed on warm-water reefs (Noronha, Rocas), while pelagic productivity shifted toward upwelling margins and island wake effects.

• Bølling–Allerød (c. 14,700 – 12,900 BCE): Rapid warming/moistening boosted SSTs; the SE trades relaxed slightly, gyre stratification increased, and reef growth rebounded in the west. Seasonal plankton blooms along current boundaries enriched food webs for fish, turtles, and seabirds.

• Younger Dryas (c. 12,900 – 11,700 BCE): Modest cooling nudged productivity back toward wind-driven zones and island wake upwelling; reef growth slowed but persisted in sheltered lagoons.

• Early Holocene (after c. 11,700 BCE): Rising seas drowned LGM terraces, establishing modern shorelines; warm, stable SSTs favored rapid reef expansion (especially at Rocas, the South Atlantic’s classic atoll) and broadened turtle nesting beaches on newly formed sand cays.

Islands, Reefs, and Ecologies

• Mid-ocean volcanoes (Ascension, St Helena): Basaltic cones with young lava fields, cinder ridges, and scant fresh water; lee-side eddies created island mass effects that concentrated plankton and small pelagics. Harsh, arid climates on land; cliffs and ledges hosted immense booby, frigatebird, and tern rookeries.

• Western ridge and seamount arc (Noronha, Rocas, São Pedro & São Paulo, Trindade–Martim Vaz): Mix of volcanic islands and reef platforms. Rocas—a low-lying ring of coral—supported lagoons rich in juveniles of reef fish and invertebrates. Noronha and Trindade had rocky shores and pocket reefs, with nutrient pulses from internal waves and current shear.

• Pelagic highways: Humpback and other baleen whales transited seasonally; tuna, billfish, and sharkspatrolled thermal fronts. Green and hawksbill turtles used multiple islands as nesting sites.

Human Presence

• None. Distances, weak archipelagic stepping-stones, and open-ocean conditions placed this basin far beyond late Pleistocene seafaring capacity. Ecosystems evolved without terrestrial predators or human fire.

Environmental Dynamics

• Gyre stratification vs. upwelling: The gyre core remained oligotrophic (blue water); biological hotspots formed where currents hit islands/seamounts, at fronts, and along Benguela margins.

• Volcanism and erosion: Intermittent eruptions (especially on the younger edifices) refreshed soils and altered coastlines; wave action reworked LGM benches into early-Holocene beach ridges.

• Seabird nutrient pumps: Massive colonies moved marine nutrients ashore, fertilizing sparse island flora and nearshore waters via guano runoff.

Symbolic and Conceptual Role

For contemporaneous peoples of Africa and South America, this was an unseen blue wilderness—a wind-belt and current system felt only indirectly in coastal weather and fish migrations, not mapped in any oral geography.

Transition Toward the Holocene

By 7822 BCE, warm, stable seas and higher stands had established today’s island outlines, reef flats were broad and productive, and seabird/turtle rookeries flourished on predator-free shores. The Northern South Atlantic had become a mosaic of pelagic deserts and island-fed oases—still entirely untouched by human hands.

South Atlantic (28,577 – 6,094 BCE): Late Pleistocene → Early Holocene — Deglaciation, Gyre Highways, and Rising Island Ecosystems

Geographic & Oceanographic Frame

Spanning from the sub-Antarctic rim to the mid-latitude gyre, the South Atlantic comprised two linked but contrasting belts:

• Southern South Atlantic (sub-Antarctic arc): the Tristan–Gough chain, ice-draped Bouvet, glacier-bound South Georgia and the South Sandwich arc, and the South Orkney Islands—volcanic and periglacial outposts embedded in the Antarctic Circumpolar Current (ACC) and swept by the westerlies.

• Northern South Atlantic (gyre core and western ridge): the Ascension–St Helena segment of the Mid-Atlantic Ridge and Brazil’s offshore line of Fernando de Noronha, Rocas Atoll, São Pedro & São Paulo, and Trindade–Martim Vaz—arid, oceanic islands fringed (in places) by reefs and ring atolls, set within the South Equatorial Current and the subtropical gyre.

No permanent human presence touched either belt during this epoch; the region’s story is one of ice, wind, and water reorganizing life at planetary scale.

Climate Pulses & Sea-Level Change

The interval bridges the Last Glacial Maximum (LGM, ~26.5–19 ka) and the onset of the Holocene:

• LGM: Global sea level stood ≈120 m lower, exposing broad coastal benches; sea ice spread far north; South Georgia and the South Orkneys lay under expanded ice caps reaching tidewater; Bouvet remained largely glaciated. Strengthened trades intensified Benguela upwelling off southwest Africa; cool, oligotrophic conditions dominated the gyre. Coral accretion at warm-water outposts (e.g., Rocas, Noronha) stalled.

• Bølling–Allerød (~14.7–12.9 ka): Rapid warming and freshening seas shifted fronts poleward; ACC vigor persisted. Glaciers on South Georgia and the Orkneys began to retreat, unveiling new headlands and proglacial lakes. In the north, SSTs rose, trades relaxed, and reef frameworks re-animated in west-basin islands; seasonal productivity spikes intensified along gyre fronts and island wakes.

• Younger Dryas (~12.9–11.7 ka): A brief cool relapse nudged productivity back toward wind-driven margins; reef growth slowed but persisted in sheltered lagoons; sub-Antarctic snowfall ticked up and outlet glaciers pulsed.

• Early Holocene (post-11.7 ka): Sea level climbed by tens of meters toward modern stands, drowning LGM terraces and fixing contemporary shorelines. Sub-Antarctic climates stabilized—cold, windy, moist—with peat initiation in leeward basins on Kerguelen-like platforms mirrored at South Georgia and parts of the Orkneys. In the north, warm, stratified SSTs expanded reef habitat (notably at Rocas, the South Atlantic’s classic atoll) and widened turtle-nesting beaches on new sand cays.

Ecosystem Assembly & Expansion (No Human Presence)

With ice in retreat and coastlines reworked, life spread rapidly:

• Sub-Antarctic belt: Tussock grasses, mosses, lichens, and cushion plants colonized freshly deglaciated slopes and moraines; peat began to accumulate in saturated hollows. Penguin (king, macaroni, gentoo) rookeries multiplied on new shingle terraces; albatross and petrel colonies rimmed cliffs; fur and elephant seals reoccupied emerging beaches. Offshore, the ACC’s krill-rich conveyor fueled surging baleen whale populations and dense pelagic food webs.

• Gyre islands: On Ascension and St Helena, basaltic cones with scant freshwater supported sparse xeric flora; island-wake eddies (“island mass effect”) concentrated plankton and small pelagics, drawing boobies, terns, and tuna. Along Brazil’s offshore arc, Rocas’ ring-reef lagoons flourished as coral accretion resumed; Noronha and Trindade hosted mixed rocky reefs and pocket corals, while São Pedro & São Paulo sustained remarkable seabird and fish aggregations. Green and hawksbill turtles nested on expanding beaches; pelagic predatorscruised gyre fronts.

Movement & Interaction Corridors

Oceanic and atmospheric circulation knit the belts into one system:

• The ACC and westerlies linked Tristan–Gough–Bouvet–South Georgia–Orkneys, transporting nutrients, ice, and biota around the hemisphere.

• The South Equatorial Current and subtropical gyre connected Noronha–Rocas–Trindade–St Helena–Ascension, while Benguela upwelling along Africa’s margin and island wakes created predictable feeding hotspots.

• Whale migrations bridged north–south belts seasonally; seabirds stitched the oceanic mosaic, moving marine nutrients ashore as guano and back to sea, reinforcing cross-realm productivity.

Symbolic & Cultural Dimensions

Human symbolic activity is absent; the islands lay beyond the range of late Pleistocene seafaring. The only “rituals” inscribed were ecological: annual penguin returns, seal pupping cycles, whale passage, and glacial advance–retreat—a natural chronicle of recurrence written in ice and surf.

Environmental Resilience & Feedbacks

Sub-Antarctic and gyre ecosystems displayed robust adjustment to large climate swings:

• Relocation and recolonization: Penguins and seals shifted rookeries/haul-outs with retreating ice and changing surf exposure; pioneer plants rapidly stabilized new substrates.

• Biogeochemical coupling: Guano-driven nutrient pumps enriched thin island soils and nearshore waters; krill dynamics tracked sea-ice phenology, buffering higher trophic levels.

• Physical buffers: Peatlands and kelp forests moderated hydrologic and wave energy extremes; volcanic ash inputs periodically reset and fertilized soils.

Long-Term Significance

By 6,094 BCE, the South Atlantic’s dual identity was established: a thriving sub-Antarctic archipelago of peat-forming, bird-and-seal–rich islands to the south, and a string of oligotrophic mid-ocean oases to the north. Though unvisited by humans, these belts had reached a Holocene steady state—a biologically powerful, interconnected seascape that would later frame the first episodic human sightings and, much later, sustained voyages across the Atlantic’s southern reaches.

Northern South Atlantic (7,821–6,094 BCE): Early Holocene Warming and Growing Green Patches

Geographic & Environmental Context

The subregion of Northern South Atlantic includes Saint Helena and Ascension Island. Cliff-bound coastlines, talus aprons, and a few pocket beaches edged uplifted volcanic plateaus; crater basins and lava fields structured interior microhabitats.

Climate & Environmental Shifts

Early Holocene warming raised sea level toward modern stand, drowning some glacial benches and reworking beaches. Trades remained persistent; SSTs warmed; dust flux slackened relative to glacial highs. Convective showers and cloud-cap moisture marginally increased effective precipitation on windward slopes.

Subsistence & Settlement

No humans. Vegetation thickened in gullies and cloud-capture zones—ferns, herbs, grasses, with incipient shrublands on Saint Helena’s higher ridges. Seabirds expanded nesting on stabilized ledges; turtles found higher beach crests as seas rose; reef flats hosted diverse invertebrates and fish nurseries.

Technology & Material Culture

Holocene microliths and early ceramics developed elsewhere; island surfaces remained entirely natural—lava, soil crusts, shells, and guano.

Movement & Interaction Corridors

Gyre circulation and trades continued to shuttle marine life; pelagic predators tracked eddies spun from the South Equatorial Current. Seabird flyways stitched west Africa, Brazil, and these mid-ocean outliers.

Cultural & Symbolic Expressions

None human—only ecological “rituals” of colony return and turtle nesting seasons.

Environmental Adaptation & Resilience

Plants exploited fog drip and hollows; seabirds shifted colonies after storm rockfalls; turtle nesting migrated upslope with rising seas; nutrient loops (guano → soil → plants → detritivores) intensified.

Transition

By 6,094 BCE the islands held a larger, still patchy terrestrial green, while surrounding seas surged with Holocene productivity.

South Atlantic (7,821 – 6,094 BCE): Early Holocene — Ice Retreat, Green Shores, and Ocean Corridors of Life

Geographic & Environmental Context

The South Atlantic in the Early Holocene stretched from the tropical gyre islands of Saint Helena and Ascension to the storm-lashed subantarctic arc of Tristan da Cunha, Gough, Bouvet, South Georgia, the South Sandwich, and South Orkney Islands.
All were volcanic outposts rising from the Southern Ocean, encircled by the Antarctic Circumpolar Current (ACC)and bound together by the migrations of whales, seals, and seabirds.

• Northern chain: Saint Helena and Ascension—mid-ocean plateaus of basalt cliffs and crater basins, catching cloud moisture from persistent trades.

• Southern chain: Tristan da Cunha, Gough, Bouvet, South Georgia, South Sandwich, and the South Orkneys—glaciated islands fringed by fjords and tundra benches newly freed from ice.

Between them rolled one of Earth’s most productive ocean gyres, linking the tropics, temperate South Atlantic, and the Antarctic seas.

Climate & Environmental Shifts

The Holocene Thermal Maximum brought general warming and sea-level rise toward modern positions:

• In the north, SSTs increased, precipitation rose slightly, and windward slopes developed cloud-forest pockets.

• In the south, ice retreated rapidly on South Georgia and the Orkneys, exposing valleys and headlands; Bouvet remained mostly ice-clad; the westerlies intensified, yet summers lengthened.
  The ocean entered a period of nutrient-rich stability—a constant, wind-driven upwelling system that sustained vast krill and plankton blooms.

Subsistence & Settlement

No humans yet reached these remote latitudes. Instead, ecosystems re-colonized freshly exposed ground:

• Northern South Atlantic:
  Vegetation thickened on Saint Helena and Ascension—ferns, grasses, and early shrubland in moist hollows; seabirds nested in cliffs and lava tubes; green turtles returned annually to pocket beaches.

• Southern South Atlantic:
  On Tristan and Gough, tussock grasslands, mosses, and herbs spread across volcanic slopes; penguin colonies (king, gentoo, macaroni) multiplied on ice-free shores; fur and elephant seals crowded new beaches.
  South Georgia’s fjords, newly deglaciated, filled with seals and seabirds; whales converged in summer feeding grounds.
  Bouvet and the South Sandwich remained marginal but hosted pioneer colonies on isolated ledges.

Across the region, biological communities advanced unimpeded by human presence—true Holocene sanctuaries of natural succession.

Technology & Material Culture

While humans elsewhere were shaping stone, bone, and clay into the first farming toolkits, the South Atlantic islands remained entirely pre-anthropic. No technology, no fire, no modification—only the slow architecture of wind, waves, ice, and guano.

Movement & Interaction Corridors

Life circulated on planetary scales:

• The ACC distributed nutrients among the islands, while gyre eddies funneled warm and cold currents that defined ecological boundaries.

• Whales and seals migrated annually—south in summer to feed in krill-rich waters, north in winter to breed.

• Albatrosses, petrels, and shearwaters traced hemispheric orbits linking Africa, South America, and Antarctica.

• Turtles rode equatorial drifts to forage around the northern islands.
  In effect, the South Atlantic was a biological highway, joining three continents through movement alone.

Cultural & Symbolic Expressions

No human symbolism yet touched these shores. The island “rituals” were ecological: the cyclic return of penguins and turtles, the synchronous molting of seals, the seasonal whale chorus—natural calendars of abundance and renewal.

Environmental Adaptation & Resilience

Ecological resilience was dynamic and self-reinforcing:

• Plants colonized bare moraines and lava soils, stabilizing slopes with root mats and peat.

• Seabird guano enriched sterile ground, accelerating plant succession and sustaining dense invertebrate webs.

• Marine populations adjusted to new coastlines and variable ice margins, shifting breeding grounds as glaciers retreated.

• Nutrient loops—sea → land → sea—tightened, maintaining productivity even through storm seasons.

Long-Term Significance

By 6,094 BCE, the South Atlantic had fully entered the Holocene balance:

• Northern islands supported patchy but resilient green belts amid the trades.

• Southern islands thrived as booming subantarctic rookeries and whale pastures.

• The ACC and westerlies operated as stable planetary engines, ensuring continuous biological exchange.

Untouched by humankind, these archipelagos became primeval laboratories of resilience—proving how, at the meeting of ocean and ice, life could rebound, diversify, and endure long before human sails crossed the horizon.

Northern South Atlantic (6,093–4,366 BCE): Mid-Holocene Highstand, Cloud Forest Seeds

Geographic & Environmental Context

The subregion of Northern South Atlantic includes Saint Helena and Ascension Island. Marine terraces neared present elevations; high ridges intercepted clouds; young cinder cones and lava tongues (Ascension) contrasted with deeply dissected massifs (Saint Helena).

Climate & Environmental Shifts

Near-modern sea level; warm SSTs; stable trades with seasonal ITCZ shifts. On Saint Helena’s heights, persistent cloud belts fostered humid summit habitats; Ascension’s drier cone still gathered fog in lee gullies.

Subsistence & Settlement

No humans. Proto-cloud-forest elements (tree ferns, woody composites on Saint Helena) took hold in wet belts; drought-tolerant shrubs and tuft grasses dominated lee slopes. Seabirds, crabs, land snails, and detritivores expanded with richer soils; turtles continued seasonal nesting.

Technology & Material Culture

None locally; elsewhere, pottery horizons spread. Island “archives” were peat pockets, guano layers, and slope colluvium.

Movement & Interaction Corridors

Gyre fronts and eddies aggregated plankton and forage fish; long-range shearwaters and tropicbirds cycled across the basin.

Cultural & Symbolic Expressions

None.

Environmental Adaptation & Resilience

Vertical zonation diversified refugia: wet summits vs. arid skirts; colonies re-sited after cliff failures; beach-ridge growth buffered nests from surge. Soil formation accelerated beneath colonies, stabilizing vegetation mosaics.

Transition

By 4,366 BCE, Saint Helena supported small humid highland patches amid dry skirts; Ascension remained mostly arid with greener ravines—both ringed by prolific pelagic seas.

South Atlantic (6,093–4,366 BCE): Middle Holocene — Flourishing Ecosystems of Wind and Sea

Geographic & Environmental Context

The South Atlantic in the Middle Holocene stretched across a band of subantarctic and mid-ocean islands from the Tristan da Cunha–Gough chain in the north to South Georgia, the South Sandwich, Bouvet, and the South Orkneys in the south, with the isolated Saint Helena and Ascension rising near the equator.
Together, these island arcs and volcanic pinnacles formed an unbroken biological bridge between Africa, South America, and Antarctica, all swept by the Antarctic Circumpolar Current (ACC) and the Southern Hemisphere westerlies.
Each cluster—northern, mid, and southern—developed distinctive yet interconnected ecological systems: humid cloud-belt uplands, tundra-like grasslands, and glacier-fringed fjords alive with birds and seals.

Climate & Environmental Shifts

By the Middle Holocene, global warming had peaked, producing the Hypsithermal optimum:

• In the northern and mid-latitude islands (Saint Helena, Ascension, Tristan, and Gough), sea levels stabilized near modern positions, while trades and westerlies reached equilibrium.

• Cloud forests began to develop on Saint Helena’s summits; Ascension remained arid but sustained fog-fed gullies.

• In the southern subantarctic belt (South Georgia, South Orkneys), glaciers retreated, exposing fjords and valleys that became colonization zones for plants, penguins, and seals.

• Bouvet and the South Sandwich Islands, still mostly ice-covered, acted as stepping stones for seabirds, while westerly storm belts maintained constant renewal of nutrients and sediments.

Seasonal sea ice reached its minimum extent of the Holocene, creating a highly productive circumpolar oceanic ecosystem.

Subsistence & Settlement

No humans had yet entered this oceanic realm.
Instead, the region was defined by self-organizing ecological communities that flourished in isolation:

• Tristan da Cunha and Gough: Volcanic highlands with expanding fern–grass mosaics; tussock meadows supported burrowing seabirds and seals.

• Saint Helena: Cloud forests of ferns, composites, and tree heaths established on summits, contrasting with xeric lowlands of shrubs and succulents.

• Ascension: Lava plains remained dry, but fog-capture vegetation stabilized gullies; nesting turtles and seabirds ringed beaches.

• South Georgia and the South Orkneys: Ice-free valleys filled with moss and cushion plants; tussock grasslands expanded along deglaciated coasts.

• Penguins, seals, and seabirds formed dense rookeries across the subantarctic arc, their guano fertilizing soils and sustaining invertebrate webs. Offshore, krill and plankton blooms supported whales, fish, and squid in immense abundance.

Technology & Material Culture

Human technology did not reach these islands during this period.
While pottery, ground stone, and domestication spread elsewhere, the South Atlantic remained untouched—a natural laboratory of unmodified ecosystems, where biological succession rather than human engineering drove landscape transformation.

Movement & Interaction Corridors

The ACC and atmospheric gyres bound all the islands into a single biological super-system:

• Whales followed annual feeding circuits from Antarctic krill fields to tropical breeding grounds, using the South Georgia–South Orkney–Bouvet corridor as summer foraging range.

• Seabirds—especially albatrosses, petrels, and shearwaters—linked Africa, South America, and Antarctica through hemispheric migrations.

• Penguins and seals shifted rookeries as glaciers receded, occupying new beaches and headlands.

• In the northern arc, Saint Helena and Ascension lay within the South Equatorial Current, drawing species from three continents and forming a biological connection between tropical and subpolar ecosystems.

Cultural & Symbolic Expressions

There were no human monuments or myths here, but the islands themselves became ecological calendars:

• The annual return of penguins, the breeding cycles of seals, and the migration of whales marked the turning of the seasons.

• Volcanic eruptions, glacier surges, and rookeries’ guano terraces created enduring natural “records” of change—biogenic archives that functioned as the symbolic language of the unpeopled South Atlantic.

Environmental Adaptation & Resilience

Life persisted through flexibility and renewal:

• Vegetation colonized ash, moraine, and guano-enriched soils; peat formation stabilized moisture and carbon.

• Bird and seal populations adjusted breeding sites with shoreline evolution; krill and plankton communities tracked sea-ice shifts.

• Species turnover and recolonization ensured that disturbance—storms, frost, ash, and surge—was a creative force, maintaining diversity and ecological balance.

These systems demonstrated maximum resilience through mobility, reproduction, and opportunistic colonization—adaptations that sustained one of the most productive oceanic ecosystems on Earth.

Long-Term Significance

By 4,366 BCE, the South Atlantic had stabilized into a mature Holocene biosphere:

• The northern islands (Saint Helena, Ascension, Tristan, Gough) supported rich vegetation belts and nesting fauna.

• The southern chains (South Georgia, South Orkneys, South Sandwich, Bouvet) thrived as polar–subpolar interfaces, where retreating glaciers met booming life.

• The ocean between pulsed with krill, fish, and whales, its nutrient loops fueled by the ACC’s perpetual motion.

Still unseen by humans, this was a world already full—a living engine of wind, wave, and migration, poised to endure millennia before the first sails cut across its waters.

Northern South Atlantic (4,365–2,638 BCE): Mature Holocene Mosaics

Geographic & Environmental Context

The subregion of Northern South Atlantic includes Saint Helena and Ascension Island. Cliff shelves, talus slopes, and sporadic beaches encircled lava/cap-rock interiors; summit fog belts on Saint Helena contrasted with Ascension’s xeric cones.

Climate & Environmental Shifts

Holocene stability with modest century-scale variability. Trades reliable; occasional ITCZ excursions brought convective rains. Sea level hovered near present.

Subsistence & Settlement

No humans. Saint Helena: better-developed cloud-belt woodlands with tree ferns and shrubs; Ascension: grass-shrub steppe with greener gullies. Seabirds (boobies, terns, petrels) packed ledges; turtles nested on pocket beaches; land invertebrates diversified in moist hollows.

Technology & Material Culture

None. Biogenic signatures—peat lenses, guano crusts, shell middens (natural), and soil charcoal only from lightning/volcanic sources.

Movement & Interaction Corridors

Gyre-edge fronts funneled tunas and billfish; seabird highways linked three continents; turtles rode the South Equatorial drift to forage grounds.

Cultural & Symbolic Expressions

None.

Environmental Adaptation & Resilience

Fog-capture floras stabilized summit soils; deep-rooted shrubs resisted drought; colonies shifted after rockfalls; nesting adjusted to storm seasonality. Nutrient coupling sea→land→sea intensified near rookeries.

Transition

By 2,638 BCE, the islands held mature, though limited, terrestrial mosaics embedded in a highly productive pelagic realm—still unseen by humans.