Dear Mr. Albertengo,

this is not unusual when thin sandstone layers (a) are intercalated into a rather thick mudstone series as in the case shown below. The overall ratio of  mudstone/sandstone is still maintained being greater than 1 in this turbidite unit.

Best regards

H.G.Dill

Thanks for the answer Mr. Dill.

I've been working with fluvial deposits and saw several injectites like that case in the picture. In one thick sandstone layer (mayor channel) saw a few sand dikes injected but i can´t find the source of the material. I inferred that the layer suffers liquefaction and fluidization and the injection happens in the same layer. Is an assumption, but i´m not sure.

(Apologies for my english)

Regards