Between Lengyel and Gava is a big gap on the one hand, but on the other, there could have been local continuity into the South Eastern Urnfield period, leading directly to Gava:
http://www.angelfire.com/sk3/quality/Stone_Age_and_Bronze_Age.htmlThis would bring E1b into the Urnfield horizon, probably even beyond Gava, but with it, being in the centre of the accumulation of V13. If that scenario would be true, it would be similar as with R1a, first moving out of the steppe, just to come back again. In the case of E1b just from the Balkans (Vinca) to the Carpathians and back again.
Looking at the yDNA clades, the timing fits as well for a LBA-EIA expansion from one single centre. Very clear cases are E-Z5017 and E-Z5018. If you look where most of the spread and diversification of their subclades happened, its between 1.600 to 600 BC.
https://www.yfull.com/tree/E-Z5017/https://www.yfull.com/tree/E-Z5018/For many of its subclades a date like 800-400 BC was the last point in time where highly diversified clades had a TMRCA, after that they spread out to very different regions of Europe and beyond.
Anther clear case is
https://www.yfull.com/tree/E-Y16729/Being split into a basal Balkan branch, one Northern European and one Near Eastern. With more samples a trail will be found and more diversity, pointing again to the LBA-EIA original spread and most likely with Greeks into the Near East during Hellenistic times.
In general, most clades under E-CTS1273 seem to repeat this pattern, at least it seems so to me, especially if considering the range of the estimates and some intermediate samples lacking, it just fits:
https://www.yfull.com/tree/E-CTS1273/The time up to 2000 BC was like a hiatus, "nothing happened", new clades might have emerged, but they didn't split or distribute on a grander scale. Then between 2.000-300 BC, with a peak between 1.600-600 BC, "most of the action took place". This really implies to me, that the major lineages of E-V13 lived together in one place up to about 2.000 BC, and dispersed on a grand scale in time from Urnfield to Hallstatt.
Another aspect of this is that this big "jumps", huge distances between samples from one clade also date, for the most part, to this time frame. Its not from before or later as much, like from Roman or late historical times. Of course, such tribal and individual migrations did occur, but most of the spread and splits date to the LBA-EIA.
Decisive is that Pannonia and the later Illyrian zone seems to have been largely free of any significant portion of E-V13 by the Early to Middle Bronze Age. Without an association of Urnfield with the E-V13 expansion and frequency in the pre-Roman and Roman Iron Age, that pattern is almost impossible to explain, unless we assume a large scale infiltration almost exclusively in Roman times. Much more likely is that the former core zone of Illyrian and Thracian was to the North, associated with the Southern Urnfield horizon, and spread along pretty much the same pathways as the later (Southern) Slavs did, through Pannonia and around the Carpathians, down to the Balkans. In Pannonia most of the E-V13 was later replaced by the various migrations from the steppe, the Germanics and Slavs, in the more mountainous regions of the Balkans it could largely keep its position, even though its numbers seem to have been reduced there as well, with some exceptions.
Once we get LBA and EIA samples, which at times can be hard, because of the use of cremation for the burial rite, we will see for sure. But what else can be deduced from the fact that before Urnfield the region had practically zero E-V13 and was dominated by R1b, R1a and I, but after the Urnfield expansion and the Gava horizon the whole region was packed with E-V13? And looking at sites like Teleac, the best associated is with Iron working specialists (Hallstatt penetration!) and tribes evading Northern pressure, moving down to evade it. Somewhere around Slovakia and the Northern Carpathian region might be a good place to search for E-V13. Also interesting that some early Slavs seem to have had sister clades of V13, like the Viking sample with E-L791 from Gotland.