In this post we present and discuss information on the very intriguing subject of possible ancient Transoceanic journeys of the Aegeans towards the American Lands.
From the very interesting paper titled “The forgotten Geographic and Physical – Oceanographic knowledge of the Prehistoric Greeks” (Bulletin of the Geological Society of Greece, 43, 92-104) by I.D. Mariolakos (2010), we read:
“Many believe that the Greek Mythology is a figment of the vivid imagination of the ancient Greeks. Consequently, until the end of the 19th century, all the experts – scientists and especially the archaeologists and the historians, believed that every writing of the ancient authors, such as Hesiod, Plato, Strabo, Diodorus Sicilus and mainly Homer, connected to mythology, lacked even a seed of truth. Consequently, the Greek Myths were all fantastic stories. It was only after the excavations of Schliemann, that it was proven that all of Homer’s writings concerning Troy were true, and not only that, but that in Greece, cities like the Mycenae existed and they were the opponents of the Trojans, etc.
Nevertheless, even nowadays, many believe that all included in these writings do not correspond to the truth. Our own research, concerning the accuracy of many physical and geological descriptions, given by various ancient authors, and especially by Homer, Hesiod, the Orphics, Diodorus Sicilus, Plutarch and others, has shown that the prehistoric Greeks knew many on the physical-oceanographic characteristics of mainly the Atlantic Ocean. Of course, all the above, for unknown reasons, are not described in a way that are easily understood by everyone, but as a myth, part of the Greek Mythology.”
“I believe that it is a MISTAKE to consider the Greek Mythology as a beautiful fairytale. The Greek Mythology is actually the most ancient history of the peoples who have lived at the land which was later named Hellas (Greece). This land is the Aegean and the peri-Aegean area. The Greek Mythology constitutes the Pre-history of the first Hellenes.”
“Geo-mythology is a branch of the Geosciences, dealing with the physical-geological conditions during mythological era and, through this to find the interrelation between Geology and Mythology. My experience, as a geologist who has spent his life studying the Geology of Greece, has shown that a great part of the Greek Mythology is indirectly influenced by the physical – geological processes of the Aegean and Peri-Aegean areas.”
“This battle, referred in the Greek Mythology as Titanomachy, resulted in the defeat and the punishment of the Titans, as well as to their exile from Greece, and the Mediterranean Sea, in general.”
“Three of the most important Titans are Oceanus, Atlas and Cronus (Satturn by the Romans).
Oceanus, according to Hesiod, did not take part in the Titanomachy, but he had already left the Mediterranean with his sister and wife, Tethys, and had gone to the place where the sun sets. This Titan gave his name to the endless sea that surrounds the land of Libya ( = Africa) and Europe, e.g. Ocean = Ωκεανός.
Atlas, who had lived and had reigned in the central Peloponnesus in Arcadia, and specifically on Mainalon mt., was exiled by Zeus at the north-western part of Africa, on mount Atlas. He was then punished to carry the celestial globe on his shoulders. Atlas gave his name to the neighbouring Ocean, since then known as Atlantic Ocean, as well as to the great island “Atlantis”, mentioned by Plato, whose geographical position has been unknown, since it had been destructed by a natural disaster, long before the time of Plato.”
“Finally, Zeus and the other Olympians defeated the Titans and exiled them to a far place of the west. But where?”

(After the Titanomachy) “Cronus on the other hand, initially reached Western Europe, on the coast of the Atlantic Ocean and then it seems that he travelled further, firstly to the north and then to the west.
The final place of exile of the leader of the Titans has been described by Plutarch* in such a detail that no doubt remains that the prehistoric Greeks of these ancient times had discovered places, which were unfortunately later forgotten. Worth to note that the hero Hercules visited the place of Cronus exile, but much later.”
*(Plutarch, Moralia, Concerning the Face Which Appears in the Orb of the Moon)
NovoScriptorium: At this point it is necessary to read Plutarch’s text, translated in English (Source: Moralia, Vol. XII of the Loeb Classical Library):
“26 1 Almost before I had finished, Sulla broke in. “Hold on, Lamprias,” he said, “and put to the wicket of your discourse lest you unwittingly run the myth aground, as it were, and confound my drama, which has a different setting and a different disposition. Well, I am but the actor of the piece, but first I shall say that its author began for our sake — if there be no objection — with a quotation from Homer:
An isle, Ogygia, lies far out at sea,
a run of five days off from Britain as you sail westward; and three other islands equally distant from it and from one another lie out from it in the general direction of the summer sunset. In one of these, according to the tale told by the natives, Cronus is confined by Zeus, and the antique Briareus, holding watch and ward over those islands and the sea that they call the Cronian main, has been settled close beside him. The great mainland, by which the great ocean is encircled, while not so far from the other islands, is about five thousand stades from Ogygia, the voyage being made by oar, for the main is slow to traverse and muddy as a result of the multitude of streams. The streams are discharged by the great land-mass and produce alluvial deposits, thus giving density and earthiness to the sea, which has been thought actually to be congealed. On the coast of the mainland Greeks dwell about a gulf which is not smaller than the Maeotis and the mouth of the Caspian sea**. These people consider and call themselves continentals and the inhabitants of this land islanders because the sea flows around it on all sides; and they believe that with the peoples of Cronus there mingled at a later time those who arrived in the train of Heracles and were left behind by him and that these latter so to speak rekindled again to a strong, high flame the Hellenic spark there which was already being quenched and overcome by the tongue, the laws, and the manners of the barbarians. Therefore Heracles has the highest honours and Cronos the second. Now when at intervals of thirty years the star of Cronus, which we call ‘Splendent’ but they, our author said, call ‘Night-watchman,’ enters the sign of the Bull, they, having spent a long time in preparation for the sacrifice and the expedition, choose by lot and send forth a sufficient number of envoys in a correspondingly sufficient number of ships, putting aboard a large retinue and the provisions necessary for men who are going to cross so much sea by oar and live such a long time in a foreign land. Now when they have put to sea the several voyagers meet with various fortunes as one might expect; but those who survive the voyage first put in at the outlying islands, which are inhabited by Greeks, and see the sun pass out of sight for less than an hour over a period of thirty days, — and this is night, though it has a darkness that is slight and twilight glimmering from the west. There they spend ninety days regarded with honour and friendliness as holy men and so addressed, and then winds carry them across to their appointed goal. Nor do any others inhabit it but themselves and those who have been dispatched before them, for, while those who have served the god together for the stint of thirty years are allowed to sail off home, most of them usually choose to settle in the spot, some out of habit and others because without toil or trouble they have all things in abundance while they constantly employ their time in sacrifices and celebrations or with various discourse and philosophy, for the nature of the island is marvellous as is the softness of the circumambient air.”
**(At this point the correct translation of the ancient text is that “the Gulf lies on the same line as the mouth of the Caspian Sea”)
“From the above mentioned text, anyone can locate the geographical position of the island of Cronus’ exile, the travels of the people of Cronus (Cronians), the position of the Gulf of the Great Continent in relation to that of the Caspian Sea, and more.”

“If Ogygia corresponds to the present-day Iceland, then the 3 islands located to the west, must be Greenland, New Foundland and Buffin Isl. But their distances from Iceland are not equal.
If the name Ogygia corresponds to the present-day Greenland, then the 3 islands should be New Foundland, Buffin Isl. and Breton Isl. In my opinion, this version is not correct.
c. “…In one of these, according to the tale told by the natives, Cronus (Saturn) is confined by Zeus, and the antique Briareus, holding watch and ward over those islands and the sea that they call the Cronian main, has been settled close beside him…”
If this is so, Cronus should have been confined in one of the three above mentioned islands, i.e. Greenland, Buffin Isl. or New Foundland. Concerning the Cronian main (Sea), a name that has been given by the Hypeboreans, it should be the North Atlantic Ocean (North Sea) and mainly the “cold sea”, in other words the Sea that is partly, and from time to time, frozen, that is the Arctic Ocean.
d. “…The great mainland, by which the great ocean is encircled, while not so far from the other islands, is about five thousand stades from Ogygia, the voyage being made by oar, for the main is slow to traverse and muddy as a result of the multitude of streams.”
They knew that, west of these islands a mainland existed. But which could this great mainland be? It is obvious that the only great continent, west of the three great islands, which encircles the great Ocean, is the present-day North America. It is important to underline that Plutarch is not only speaking about a land, but about a great continental land ( = μεγάλη ηπειρωτική χώρα).“
“Plutarch continues:
f. “…On the coast of the mainland Greeks dwell about a gulf which is not smaller than the Maeotis and (lies on the same line as) the mouth of the Caspian Sea. These people consider and call themselves continentals and the inhabitants of this land islanders because the sea flows around it on all sides…”
If we take into account that Maeotis is the present-day Azov Sea, and based on a common school geographical atlas, we draw a “straight” line from the “mouth” (that is the northern coast) of Caspian Sea, then we see that the gulf, on the coast of which the Greeks dwell, is the St. Laurence Gulf.”

“(Recalling: Now when at intervals … twilight glimmering from the west)
…two questions rise, namely: (i) ”Where did the prehistoric Greeks know that the sun passes out of sight for less than an hour?” and (ii) “Which islands see the sun “passing out” for less than an hour?” “
“But, which are the islands that see the sun “passing out” for less than an hour? It is well known that the Arctic Cycle coincides to the latitude of 66.5o North. Consequently, the areas, and in this case the islands, which “see the sun passing out for less than an hour” should lie a little to the south of the arctic cycle.”
“Hesiod refers to the Ocean as αψόροο (back-flowing). This characterization has been render as “swaying”, in modern greek. This means that the ocean water perform a “reversible movement”, i.e. a movement along an axis. In my view, this interpretation is not accurate, since the ancient greek word αψ-ροή could be rendered as “wild flow”, in other words, turbulent flow.
Homer refers to the Ocean, using the terms deep-flowing (βαθύροος) and deep-vortexed (βαθυδίνης). Deep-flowing means that the river Ocean flows not only on the surface, but also in depth, and this deep flow is not laminar but turbulent, that’s why the Ocean is also characterised as deep-vortexed (βαθυδίνης).
Today, we know that the oceanic currents extend to a depth of about 800 – 1200 m. and that up to that point their flow is turbulent. In recent times, this has been verified with the use of different instruments that allowed the simultaneous measurement of the flow velocity as well as the depth. But, at the time of Homer, how could anyone know that the river Ocean displays a turbulent flow both on the surface and in depth?“
“Mathew Maury, in his book «Physical Geography of the Sea» (1855) wrote:
«There is a river in the ocean. In the severest droughts it never fails, and in the mightiest floods it never overflows….Its current is more rapid than the Mississippi or the Amazon…»,
Compare the above passage to that of Homer
“…he set the mighty stream of the river Oceanus…” (Iliad,XVIII) / «…και έθεσεν επάνω τον μεγαλόσθενο / ποταμό του Ωκεανού…» (Ιλιάδα, Σ 607).
“…After we were clear of the river Oceanus…” (Odyssey, XII) / «…αφού κατέλιπε την ροή του ποταμού Ωκεανού…» (Οδύσσεια, μ1).”
“According to the writings of Plutarch, the prehistoric Greeks should have known the following:
(i) Britain and Ierne (Ireland).
(ii) Iceland, which is mentioned as Ogygia, its relative position to Britain and the distance between the two islands.
(iii) The three islands located west of Ogygia (Iceland), which should be the present-day islands of Greenland, Buffin Island and New Foundland.
(iv) That the three above-mentioned islands are equidistant.
(v) He refers to the “Cronian Main (Sea)” that, according to the Orphics, is the name given by the Hyperboreans to the present-day North Atlantic Ocean and a part of the Arctic Ocean.
They also knew:
(vi) That at the west of these three islands there was a great mainland (a great continental country) that encircles the great Sea.
(vii) That the coast of a gulf on this great continent was inhabited by Greeks.
(viii) That the size of the above-mentioned gulf is approximately the same as that of the Maeotian Sea (present-day Azov Sea).
(ix) That this gulf is located “on the same straight line” as the mouth of the Caspian Sea. This means that the northern coast of the Caspian Sea are located on the same latitude as the gulf located on the great mainland (great continent). After this detailed definition, there really must be no doubt that this gulf should be the St. Laurence Gulf of the present-day Canada, and consequently the “great mainland” is North America.
(x) They also knew that sea-currents exiting from the above-mentioned gulf towards the Atlantic carried argillaceous material (“earthiness”) that obstructed the sailing of the ships, that’s why the sailors, as they could not use the sails, they sailed by oars.
(xi) That the people that arrived there with Hercules, stayed in an area on one of the three islands, where the sun only set for one hour, for a period of 30 days.
Taking into consideration all the above-mentioned, one can indirectly draw more, concerning the knowledge of the prehistoric Greeks, beyond the confirmation of what is mentioned by Plutarch.
These indirect conclusions are the following:
(i) That they knew how to measure great surfaces, i.e. the surface of the Azov Sea (Maeotis) and that of the Gulf of St. Lawrence.
(ii) That the discovery of Iceland, of the three islands and that of the great mainland, must have taken place, according to the most conservative assessment, approx. at the beginning of the 3rd millennium B.C., i.e. at the start of the Proto-Helladic era.
(iii) That they knew the way to determine the latitude of a given area.
(iv) That long before the time of Hercules and the Argonauts, even before the time of Phrixus and Elle, they knew the Caspian Sea, the Hyperboreans, the Rippean mountains, the Sarmatian Sea (Baltic Sea), the different rivers like the Dneiper (which they called Vorysthenis), Don (Tanais) etc., as well as the people who lived in the areas between the Euxenian Pontus and the Baltic Sea (Sarmatian Sea).“

From the paper titled “mtDNA Haplogroup X: An Ancient Link between Europe/Western Asia and North America?“, by Michael D. Brown et al. (1998), we read:
“(Summary) On the basis of comprehensive RFLP analysis, it has been inferred that »97% of Native American mtDNAs belong to one of four major founding mtDNA lineages, designated haplogroups “A”–“D.” It has been proposed that a fifth mtDNA haplogroup (haplogroup X) represents a minor founding lineage in Native Americans. Unlike haplogroups A–D, haplogroup X is also found at low frequencies in modern European populations. To investigate the origins, diversity, and continental relationships of this haplogroup, we performed mtDNA high-resolution RFLP and complete control region (CR) sequence analysis on 22 putative Native American haplogroup X and 14 putative European haplogroup X mtDNAs. The results identified a consensus haplogroup X motif that characterizes our European and Native American samples. Among Native Americans, haplogroup X appears to be essentially restricted to northern Amerindian groups, including the Ojibwa, the Nuu-Chah-Nulth, the Sioux, and the Yakima, although we also observed this haplogroup in the Na-Dene–speaking Navajo. Median network analysis indicated that European and Native American haplogroup X mtDNAs, although distinct, nevertheless are distantly related to each other. Time estimates for the arrival of X in North America are 12,000–36,000 years ago, depending on the number of assumed founders, thus supporting the conclusion that the peoples harboring haplogroup X were among the original founders of Native American populations. To date, haplogroup X has not been unambiguously identified in Asia, raising the possibility that some Native American founders were of Caucasian ancestry.”
“Despite a shared consensus RFLP haplotype, substantial genetic differences exist between the Native American and European mtDNAs. Phylogenetic analysis indicates that the two groups are related—but only distantly—to each other and that considerable genetic substructure exists within both groups. Further, coalescence-age estimates for haplogroup X in the Americas, based on either RFLP or CR sequence data, clearly indicate the antiquity of this haplogroup in the New World. Overall, these data exclude the possibility that the occurrence of haplogroup X in Native Americans is due to recent European admixture and, instead, provide a rigorous demonstration that this haplogroup represents an additional founding mtDNA lineage in Native Americans.”
“Our analysis confirmed that haplogroup X is present in both modern Native American and European populations. For the Native Americans, this haplogroup encompasses »25% of the Ojibwa, 15% of the Sioux, 11%–13% of the Nuu-Chah-Nulth, 7% of the Navajo, and 5% of the Yakima. Thus, with the exception of the Na-Dene–speaking Navajo, the distribution of this haplogroup among the Native Americans appears to be restricted to northern Amerindian populations.
In studies of Native American mtDNA diversity, the co-occurrence of the same haplogroup at significant frequencies in both the modern Native American and European populations is unique. Recent European genetic admixture cannot explain the presence of haplogroup X in the Amerindians.”
“Given the apparent absence of haplogroup X in modern eastern and northern Asia, it is difficult to define a source population for haplogroup X in the Americas. The similarity between the western Asian/European and Native American haplogroup X mtDNAs appears to indicate a western Asia origin of this haplogroup. Indeed, on the basis of limited RFLP data, the coalescence time for haplogroup X in Caucasians is estimated to be 30,000–40,000 years ago (data not shown), compatible with both a Near Eastern origin of haplogroup X and its subsequent spread, probably at a low frequency, into Europe and Asia.”
“In conclusion, we have described the occurrence, variation within, and population distribution of haplogroup X mtDNAs in Native Americans. This haplogroup appears, on the basis of archaeological data, to be pre- Columbian and may have arrived in the Americas either 12,000–17,000 years ago or 23,000–36,000 years ago. Haplogroup X is remarkable in that it has not been found in Asians, including Siberians, suggesting that it may have come to the Americas via a Eurasian migration.”

From the paper titled “Origin and Diffusion of mtDNA Haplogroup X“, by Maere Reidla et al. (2003), we read:
“mtDNA and the nonrecombining part of the Y chromosome are widely used in archaeogenetic studies (Renfrew 2000; Cavalli-Sforza and Feldman 2003) that aim to reveal the human past. The uniparental inheritance and complete linkage of mutations in these two loci allow an unambiguous determination of the phylogenetic relationships between individual lineages. However, the putative genetic histories of the lineages that are obtained do not fully reflect the complex dynamics of ancient populations; thus, the data must be interpreted carefully. Phylogenetic clustering of mtDNA haplogroups has been found to be congruent with geography— there are haplogroups specific to African (Chen et al. 1995; Watson et al. 1997), Asian (Ballinger et al. 1992; Torroni et al. 1994; Kivisild et al. 2002), European/West Eurasian (Torroni et al. 1996; Macaulay et al. 1999), and Native American (Torroni et al. 1993) populations.
Haplogroup X is an exception to this pattern of limited geographical distribution. It is found, generally at low frequencies, in both West Eurasians (Richards et al. 2000) and some northern groups of Native Americans (Ward et al. 1991; Forster et al. 1996; Scozzari et al. 1997; Brown et al. 1998; Smith et al. 1999; Malhi et al. 2001), but, intriguingly, it is absent in modern north Siberian and East Asian populations (Brown et al. 1998; Starikovskaya et al. 1998; Schurr et al. 1999), which are genetically and geographically closest to those of Native Americans. Among Siberians, haplogroup X mtDNAs have only been detected in some Altaian populations of southwestern Siberia (Derenko et al. 2001).
When the sequence variation of the first hypervariable segment (HVS-I) of the control region is analyzed, haplogroup X mtDNAs from Europe and the Near East are found to yield similar coalescence times: 17,000–30,000 years before present (YBP) and 13,700–26,600 YBP, respectively (Richards et al. 2000). These estimates are consistent with a pre-Holocene origin and spread of this haplogroup into West Eurasia. For Native Americans, the relatively old presence of haplogroup X is confirmed by the analysis of ancient human remains (Stone and Stoneking 1999; Malhi and Smith 2002). Moreover, Native American haplogroup X mtDNAs form a clade distinct from that of West Eurasians and with coalescence time estimates varying widely depending on both the method of estimation and the number of assumed founders. Thus, the coalescence times ranged from 12,000–17,000 YBP to 23,000–36,000 YBP, times that are consistent with both a pre- and a postglacial population diffusion (Brown et al. 1998).”
“Subhaplogroup X1 was found to be largely restricted to the Afro-Asiatic–speaking populations of North Africa and neighboring areas, including Ethiopia, suggesting a possible geographic diffusion of X1 alongside the Mediterranean Sea and the Red Sea. This subhaplogroup is subdivided into the two clades X1a and X1b, which are defined by two and five coding region mutations, respectively. Both clades share a recurrent transition at 146 in HVS-II. The coalescence time of the entire X1 subhaplogroup using HVS-I variation is 42,900 ± 18,100 YBP, whereas the coalescence time of the X1a clade is 17,900 ± 11,900 YBP.
Virtually all (97.2%) haplogroup XmtDNAs from the Near East, the South Caucasus, and Europe were found to belong to subhaplogroup X2, as did all (100%) of those from Siberia and Central Asia and some (36.8%) of those from North Africa (table 2). Thus, subhaplogroup X2 is characterized by a very wide geographic range but also by an infrequent occurrence.”
“Three exceptions include the Druze, the Georgians, and the Orkney Islanders, among whom the frequency of X2 reaches 11%, 8%, and 7%, respectively.”
“Overall, it appears that the populations of the Near East, the Caucasus, and Mediterranean Europe harbor subhaplogroup X2 at higher frequencies than those of northern and northeastern Europe (P < .05) and that X2 is rare in Eastern European as well as Central Asian, Siberian, and Indian populations and is virtually absent in the Finno-Ugric and Turkic-speaking people of the Volga-Ural region. Coalescence time estimates based on HVS-I and coding region variation—17,900 ± 2,900 YBP and 21,600 ± 4,000 YBP, respectively—are consistent with the range expansion of X2 around or after the last glacial maximum (LGM).”
“The Native American–specific clade X2a appears to be defined by five mutations, three in the coding region (8913, 12397, and 14502) and two in the control region (200 and 16213). The transition at np 200 was seen in virtually all previously analyzed Native American haplogroup X mtDNAs, whereas the transition at np 16213 was absent in some of the Ojibwa described by Brown et al. (1998). We surveyed our Old World haplogroup X mtDNAs for the five diagnostic X2a mutations and found a match only for the transition at np 12397 in a single X2* sequence from Iran. In a parsimony tree, this Iranian mtDNA would share a common ancestor with the Native American clade. Yet, the nonsynonymous substitution at np 12397 converting threonine to alanine cannot be regarded a conservative marker, as it has also been observed in two different phylogenetic contexts—in haplogroups J1 and L3e—among 794 complete mtDNA sequences (Finnilä et al. 2001; Maca-Meyer et al. 2001; Herrnstadt et al. 2002). Therefore, the scenario that the threonine to alanine change in the haplogroup X background is indeed due to recurrence appears most plausible.
These findings leave unanswered the question of the geographic source of Native American X2a in the Old World, although our analysis provides new clues about the time of the arrival of haplogroup X in the Americas. Indeed, if we assume that the two complete Native American X sequences (from one Navajo and one Ojibwa) began to diverge while their common ancestor was already in the Americas, we obtain a coalescence time of 18,000 ± 6,800 YBP, implying an arrival time not later than 11,000 YBP.
The results of this study point to the following conclusions. First, haplogroup X variation is completely captured by two ancient clades that display distinctive phylogeographic patterns—X1 is largely restricted to North and East Africa, whereas X2 is spread widely throughout West Eurasia. Second, it is apparent that the Native American haplogroup X mtDNAs derive from X2 by a unique combination of five mutations. Third, the few Altaian (Derenko et al. 2001) and Siberian haplogroup X lineages are not related to the Native American cluster, and they are more likely explained by recent gene flow from Europe or from West Asia. Fourth, the split between “African” X1 and “Eurasian” X2 subhaplogroups of X is phylogenetically as deep as that within the branches of haplogroup U that also differ profoundly in their phylogeography. Thus, subhaplogroup U6 is largely restricted to North Africa (as X1), whereas subhaplogroup U5 is widespread in West Eurasia (as X2). The phylogeographic patterns and the coalescence times that we obtained here suggest that the basic phylogenetic structures of the mtDNA haplogroups in West Eurasia and North Africa are as ancient as the beginning of the spread of anatomically modern humans in this region. Finally, phylogeography of the subclades of haplogroup X suggests that the Near East is the likely geographical source for the spread of subhaplogroup X2, and the associated population dispersal occurred around, or after, the LGM when the climate ameliorated. The presence of a daughter clade in northern Native Americans testifies to the range of this population expansion.”

NovoScriptorium: Let’s recall here our presentation of the very informative paper titled “Old World sources of the first New World human inhabitants: A comparative craniofacial view“, by C. Loring Brace et al. (2001).
Let’s also recall another relative and very interesting post. Also of interest is this one.
For us, there is no doubt that the ancient Aegeans knew of the Americas.
(Please read e.g. here)
There is also no doubt that they had visited the American lands, most likely not only once. Otherwise they couldn’t have known of their existence or the difficulties to reach them, by Sea (the Ocean).
In the future, NovoScriptorium is aiming to present you -hopefully- all the ancient Greek references to the Ocean, oceanic journeys and the ‘Western Lands’.
Another relative post worth recalling here is this one.
As we saw above, Genetics and Anthropology (to date) are rather certain that there had been a Western Eurasian contribution to some northern Amerindian populations, i.e. some Western Eurasian population arrived in the Americas, as stated, “not later than 11,000 YBP“. More specifically, also as stated “the Near East is the likely geographical source for the spread of subhaplogroup X2“.
From the paper titled “Late Pleistocene/Early Holocene seafaring in the Aegean: new obsidian hydration dates with the SIMS-SS method“, by N. Laskaris, A. Sampson, F. Mavridis, I. Liritzis (2011) we learn that already from the 11th millenium B.C. (13,000 BP) Melian obsidian finds from Francthi prove sea-trade and maritime capabilities of its inhabitants.
To date, there is no other similar record of any other Eastern Mediterranean population with such capabilities so deep in the Past. And this is actually very reasonable; in the Aegean there had been countless of millennia of -documented- ‘seafaring evolution’ as you may read, for example, here.
It is also of some importance to recall here these posts (1, 2) , which show that several Aegean Myths had their roots very deep in the Past, at least in the Neolithic Age.
Of course, the question rises automatically: “Do you really believe that the Aegeans had reached the Americas during the Stone-Age!?”. In order to claim something like this with confidence, one must first have some Archaeological evidence available. The above indications do not constitute “proof”. Yet, we may say that, for the moment, it is the best assumption we can make. And it wouldn’t be that surpising, if we recall how well documented is the mobility of Humans since the Palaeolithic Age (e.g. 1, 2, 3).

Regardless if the Aegeans visited the Americas during the Stone-Age or not, it appears rather certain (out of many ancient texts) that they had indeed visited the lands several times and in various different epochs. Strangely enough, it is almost 100% certain that they haven’t done this during the ‘more recent times’, but, rather, somewhere deeper in the Past.
Research-Selection-Comments for NovoScriptorium: Philaretus Homerides, Maximus E. Niles, Isidoros Aggelos