There are several things you can do, depending on what you want to achieve.
Masking the strata with a distribution shader, minimum slope.
Use a power fractal, standard Perlin with no roughness at all and no strong contrast.
Use a power fractal and stretch the noise horizontally, for example, x3-y1-z3. Alternatively: warp the power fractal along the x and z-axes.
Or combine several of these techniques until you are satisfied.