Studying the Hadean is Difficult!
For a start there is not much of it! Perhaps 20km² on Hudson Bay. Most studies have concentrated on zircon grains found in younger rocks. The best that can be said is that there was felsic magma and water was about.
But there are other approaches. The early Earth was characterised by impacts from space, but direct evidence of these is missing on the Earth. The surface of the moon however records these and scaling up to the size of the Earth indicates that they would have a major influence on the Hadean on the Earth.
This is considered in THIS ACADEMIC PAPER and is summarised in this ARTICLE. The conclusion reached is that the heat produced from the kinetic energy of the impacts would have made almost everything start to melt. Below 3.5km lots of rocks of all kinds would be melting. Above 3.5km heat loss to space would keep things relatively cool.
The Earthlogs article is well worth reading. It may be easier to understand if you read the following summary produced by Google Gemini.
The Hadean Eon (~4.6 to 4.0 billion years ago) lacks a substantial rock record, leaving geologists to rely heavily on the geochemical signatures of rare, tiny zircon grains. To shed light on this elusive era, researcher Tim Johnson and his colleagues modeled the impacts of heavy celestial bombardment on the early Earth, scaling up lunar cratering data to account for Earth's greater gravitational pull.
The study reveals that during the Hadean, the energy released by frequent asteroid impacts significantly outweighed internal radiogenic heat generation. This intense, fluctuating external energy profoundly altered Earth’s thermal dynamics. Rather than shedding heat through modern plate tectonics and mantle convection, the Hadean Earth relied on massive, rapid melting events. Magma transported immense heat directly to the surface, allowing energy to radiate into space—the most efficient planetary cooling mechanism.
The team’s modeled geotherm indicates that temperatures increased rapidly with depth. Beneath a depth of just 3.5 kilometers, the uppermost Hadean crust was in a partially molten state. At depths exceeding 10 kilometers, between 40% and 70% of basaltic crust would have been liquefied. This pervasive melting effectively nullified the traditional distinction between brittle and ductile rock behaviors.
Consequently, the simulation rules out the existence of a rigid lithosphere or stabilizing plate tectonics during this period. Instead, the Hadean mantle was dominated by chaotic, high-energy convection. This continuous recycling of early granitic and continental crust into a literal melting pot perfectly explains the near-total absence of intact Hadean rocks today. This volatile cycle of impact-driven tectonics only ceased around 3.9 to 3.8 billion years ago, when the heavy bombardment subsided and allowed stable, modern planetary geology to emerge.
