[WithinReason]

Lake Baikal sediment layer almost as deep as the Mariana Trench:

https://en.wikipedia.org/wiki/Lake_Baikal#Geography_and_hydr...

[...] and below this lies some 7 km (4.3 mi) of sediment, placing the rift floor some 8–11 km (5.0–6.8 mi) below the surface, the deepest continental rift on Earth.

[card_zero]

Oh right. Basically China has its own tectonic plate, with Baikal on the rift, top left: https://en.wikipedia.org/wiki/Amur_plate I did not know that.

[LeoWattenberg]

You may enjoy the new global tectonic map with 11000 features and 1180 "tectonic plates". https://doi.org/10.1111/ter.12662, also available on Google maps: https://www.google.com/maps/d/viewer?mid=1dXnQlelic4WjA4xKnY...