Earth, 4,700 Years Ago — A Holocene Reflection
- Tom Shankapotomous
- Oct 3
- 3 min read
Deep Time Convergence 001 — The Holocene Earth and the Ancien
Catalog ID: GEO-2025-10-13
Series: Deep Time Convergence
Era: Quaternary Period — Holocene Epoch
Approximate Age: 4,700 years BP (≈ 2675 BCE)
Overview
Deep Time Convergence is an ongoing series exploring the geological state of Earth in relation to the astrophotography targets and race venues featured elsewhere in this archive.
Each entry situates the ground beneath our feet within the greater chronology of planetary evolution — connecting sky to stone, cosmos to continent.
Entry : Earth, 4,700 Years Ago — A Holocene Reflection
In geological time, 4,700 years ago is barely measurable — the final seconds of a vast chronicle.
The Holocene Epoch had stabilized Earth’s climate after the last great glacial pulse. Ice sheets that once smothered half of North America had melted, carving valleys and leaving the broad scars of ancient rivers.
Continents stood nearly as they do today, drifting apart along invisible mid-ocean ridges.
The Holocene Climate Optimum was underway: a warm, steady phase when forests reclaimed the wounds of the Ice Age.
The planet was in a state of quiet recovery — a kind of post-traumatic stillness after eons of upheaval.
Surface and Systems
North America — The retreat of the Laurentide Ice Sheet exposed the Great Lakes basin, leaving rolling moraines, kettle lakes, and vast outwash plains.
South America — The Andes continued their slow uplift, river systems adjusting to a continent’s rising spine.
Africa and Eurasia — The Sahara was transforming from its once-green, lake-rich landscape into the desert we know today.
Oceans — Circulation patterns mirrored the modern Atlantic and Pacific gyres, and coral reefs thrived in warm shallows.
Earth’s crust was quiet, but the memory of tectonic violence remained written in stone.
Among those records, none stand more quietly proud than the Appalachian Mountains — old bones of a young world.
The Appalachian Mountains — Old Bones of a Young World
By 4,700 years BP, the Appalachians were already ancient beyond comprehension.
Their birth lay more than half a billion years in the past — relics of collisions that once raised peaks rivaling the Himalayas.
The Taconic, Acadian, and Alleghanian orogenies had folded and welded the crust of eastern North America, creating a chain that stretched unbroken from Alabama to Newfoundland.
By ≈ 2700 BCE, erosion had sculpted those massive peaks into a procession of rounded ridges and deep green valleys.
The Blue Ridge exposed the planet’s deep crystalline basement — billion-year-old gneiss and schist.
The Valley and Ridge Province displayed folded limestones, sandstones, and shales — the sediments of vanished seas.
The Piedmont and Coastal Plain gathered their runoff, transforming erosion into fertile soil.
No volcanoes flared; no earthquakes split their slopes. The drama was long past. What remained was the patience of erosion.
The Appalachians of 4,700 years ago looked much as they do today — lower, rounder, enduring. Their highest summits may have reached ≈ 6,000 ft, remnants of ancestors that once towered near 25,000.
North America — A Continent of Silence
This was a land of forests, rivers, and wind.
No agriculture, no cities — only water and weather composing the same slow hymn that had played since the glaciers’ retreat.
The Appalachians stood at the continent’s center, guardians of runoff, seed, and soil.
From them flowed the rivers that defined North America’s anatomy: the Tennessee, Potomac, and Delaware — arteries of a living, recovering Earth.
References
Berger, A. L., & Loutre, M. F. (1991). Insolation values for the climate of the last 10 million years. Quaternary Science Reviews, 10(4), 297–317.
Hatcher, R. D. (2010). The Appalachian orogen: A brief summary. Geological Society of America Memoirs, 206, 1–19.
Whittecar, G. R., & Jacobson, R. B. (2022). Geomorphic evolution of the central and southern Appalachians. Geological Society of America Bulletin, 134(5–6), 1289–1310.
Walker, M., Head, M. J., & Lowe, J. J. (2008). The formal definition and classification of the Holocene. Journal of Quaternary Science, 23(3), 241–248.
U.S. Geological Survey (2024). Appalachian Mountains: Geology, geologic history, and physiography. USGS
Comments