Some fossils/rocks like ancient plants that I'm not sure

[BunnnyZPC]

These rocks were found in a valley of Lhasa, Tibet Province, China. According to the  the local geological literature, the exposed strata here belongs to the Lower Cretaceous.

 

In the first three pics, some lines seem to converge to a single stem, and the ends of each line happen to form a fan-shape. Sorry to say that the rock is not that intact and the pictures are not that clear. I wonder if this could be a piece of fossil？ Or anybody has seen some fossils like that？

 

 

And there‘re still another two rocks, which have interesting lines on them. Maybe these're fossils?

 

 

 

By the way, I have another question here: If I get some fossils from outdoors, how can I clean it or preserve it? Is washing with water acceptable? Or I can only use the dry brushes softly? I'm so bothered by that.

 

 

If anyone can give me some guide or just share your opinion, THANK YOU SO MUCH!!

[Fossildude19]

First and third photos look like sedimentary structures, and not fossils.

The second is probably unidentifiable plant stem or rachis.

Not seeing any identifying details.

 

Cleaning depends on the makeup of the matrix involved. Some shales can get softened by water, and can ruin trace or plant fossils if brushed too hard.

Limestone, dolostone, chert, and sandstone are usually more robust and hearty, and can take cleaning with a brush and water.

Where carbonized film based fossils are involved, I would clean it very gently with water, dipping it in a basin rather than running it under a hose or faucet.

You don't want to wash or brush away the carbon film.

More robust fossils can be washed with stiffer brushes and flowing water.

[BunnnyZPC]

40 minutes ago, Fossildude19 said:

First and third photos look like sedimentary structures, and not fossils.

The second is probably unidentifiable plant stem or rachis.

Not seeing any identifying details.

 

Cleaning depends on the makeup of the matrix involved. Some shales can get softened by water, and can ruin trace or plant fossils if brushed too hard.

Limestone, dolostone, chert, and sandstone are usually more robust and hearty, and can take cleaning with a brush and water.

Where carbonized film based fossils are involved, I would clean it very gently with water, dipping it in a basin rather than running it under a hose or faucet.

You don't want to wash or brush away the carbon film.

More robust fossils can be washed with stiffer brushes and flowing water.

Thank you for the suggestions. They're so helpful!