Sharp peak in rock site

[Navids94]

Hello @andersp
I used pfile for velocity model and it was fine for the soil site, but in the rock site we had just a sharp peak. I tried several receivers on rock and changed the time function, but they all produced the same unexpected results. Could this be a result of considering only one point source?
I used following properties for crustal model in pfile:

Depth(m)	Vp	Vs	Density	Qp	Qs

1 0 6280 3487 2779 1000 500
2 1000 6280 3487 2779 1000 500
3 2000 6280 3487 2779 1000 500
4 3000 6270 3489 2777 1000 500
5 4000 6270 3489 2777 1000 500
6 5000 6128 3480 2744 1000 500
7 6000 6128 3480 2744 1000 500
8 7000 6060 3450 2729 1000 500
9 8000 6060 3450 2729 1000 500
10 9000 6250 3566 2772 1000 500
11 10000 6250 3566 2772 1000 500
12 11000 6252 3559 2773 1000 500
13 12000 6252 3559 2773 1000 500
14 13000 6312 3572 2787 1000 500
15 14000 6312 3572 2787 1000 500
16 15000 6375 3599 2802 1000 500
17 16000 6375 3599 2802 1000 500
18 17000 6380 3624 2803 1000 500
19 18000 6520 3706 2838 1000 500
20 19000 6520 3706 2838 1000 500
21 20000 6500 3720 2833 1000 500
22 21000 6500 3720 2833 1000 500
23 22000 6437 3705 2817 1000 500
24 23000 6437 3705 2817 1000 500
25 24000 6340 3661 2793 1000 500
26 25000 6340 3671 2793 1000 500
27 26000 6340 3671 2793 1000 500
28 27000 6250 3607 2772 1000 500
29 28000 6250 3607 2772 1000 500
30 30000 6180 3544 2756 1000 500

And used following input for getting 5Hz:
grid x=51878 y=25708 z=29e3 h=80

time t=120

supergrid gp=40

pfile filename=pfile_Kinburn.ppmod style=cartesian

attenuation nmech=3 phasefreq=1 maxfreq=10

refinement zmax=1200
refinement zmax=600
refinement zmax=300
refinement zmax=130

source x=47878 y=4000 z=14500 strike=306 rake=94 dip=41 m0=1.32e+16 type=Gaussian freq=12.566 t0=2

rec x=9861 y=16677 z=0 file=JSBS nsew=1 usgsformat=1 sacformat=0
rec x=8502 y=18273 z=0 file=JSSS nsew=1 usgsformat=1 sacformat=0
rec x=11200 y=16800 z=0 file=surface nsew=1 usgsformat=1 sacformat=0
rec x=8600 y=18200 z=0 file=Deepsoil nsew=1 usgsformat=1 sacformat=0

And also used the following pfile pattern(cartesian):

kinburn
200
271 0 54000(X-NS)
141 0 28000(Y-EW)
30 0 30000
-99 -99 -99 -99
.TRUE.
0 0 30
.
.
200 0 30
.
.
400 0 30

I would greatly appreciate it if someone could help me identify the source of my problem.
Thanks