This is a selected list of the oldest rivers on Earth for which there is knowledge about their existence in past times.
Generally, the age is estimated based primarily upon the age of any mountains it dissects; the age of the sea or ocean to which it eventually outflows can be irrelevant; for example, several rivers of the east side of the Appalachian Mountains are thought to be older than the Atlantic Ocean into which they flow. If a river fully dissects a mountain range, then this generally indicates that the river existed at least at the time that the mountain range rose.
| River | data-sort-type="number" | Age (Mya) | Outflow | Most significant criterion for the age |
|---|---|---|---|---|
| Finke | 400~350 | Lake Eyre (intermittent) | Predates the Alice Springs Orogeny; several other smaller rivers in the Northern Territory are of a similar age[1] [2] | |
| Meuse | 340~320 | North Sea | Paleozoic, dissects the Ardennes during the Hercynian[3] | |
| French Broad River | 340~320 | Tennessee River | Dissects the Appalachian Mountains, formed by the Alleghenian orogeny, 320–340 ma. The New, Susquehanna, and French Broad are the only significant rivers that fully dissect the Appalachian core; the Hudson River is of more recent geologic origin.[4] | |
| New | 325~260 | Kanawha River | Dissects the Appalachian Mountains, formed by the Alleghenian orogeny, 320–340 ma[5] | |
| Susquehanna | 325~260 | Chesapeake Bay | Dissects the Appalachian Mountains, formed by the Alleghenian orogeny, 320–340 ma | |
| Rhine | 240 | North Sea | Triassic, possibly older if it dissected mountains uplifted during the Hercynian in addition to the Eocene with the Alps or the Miocene with the Upper Rhine Graben | |
| Save | 205 | Indian Ocean | Formed during rifting when Gondwana broke up[6] | |
| Amur | 125 | Sea of Okhotsk | Known to be at least Cretaceous in age, but crosses mountains even older[7] | |
| Macleay | 80 | Tasman Sea | Predates uplift of Great Escarpment[8] | |
| Colorado | 75 | Gulf of California | Uplift during Laramide orogeny, see Geology of the Grand Canyon area | |
| Murrumbidgee | 75 | Murray River | Predates uplift of Australian Alps | |
| Nile | 75~65 | Mediterranean Sea | 65 to 75 for the Sudd section; the rest of the river is only 1 or 2 million years old[9] | |
| Thames | 58 | North Sea | Late Palaeocene Period Thanetian Stage[10] | |
| Indus (Sindhu) | 45 | Arabian Sea | Source in the Himalayas and Karakoram Mountains[11] | |
| Tyne | 30 | North Sea | The Tyne began to carve its valley 30 MYA, by removing softer chalk rocks and exposing harder rocks.[12] Significantly predates the last Ice Age. | |
| Yangtze (Chang Jiang) | 36.5~23 | East China Sea | Post-dates the Three Gorges formation (36.5 ma)[13] [14] | |
| Parramatta | 29~15 | Tasman Sea | Formed between the late Oligocene and early Miocene period as its waters began to cut a valley into sandstone and shale, which were laid down some 200 million years earlier[15] | |
| Columbia | 17~6 | Pacific Ocean | Between 17 million and 6 million years ago, huge outpourings of flood basalt lava covered the Columbia River Plateau and forced the lower Columbia into its present course.[16] | |
| Amazon | 11.8~11.3 | Atlantic Ocean | Waters worked through the sandstone from the west and the Amazon began to flow eastward.[17] The river flowed through a former basin of a proto-Amazon, which flowed in the opposite direction at least as old as 65 Mya, long before the formation of Andes, when it originated in the highland area that formed when the South American and African plates separated.[18] This river may predate the break-up of western Gondwana as an extension of a proto-Congo river system, 200 Mya during the Jurassic. | |
| Ohio | 3~2.5 | Mississippi River | Formed when the Laurentide Ice Sheet dammed the north flowing Teays River during the Pre-Illinoian glaciation. The drainage area of the Teays could no longer drain to the north, and so instead drained to the south, forming the Ohio River. | |