Some excerpts from that article:
The first grave.
[...]The grave has an irregular shape; the width of the northern part can be established at 8 m and narrows by 3 meters towards the south. Its length equals 62 m. More or less in the middle, it is cut by a concrete road of the period between 1962 and 1964. Its irregular shape and relatively insignificant length in comparison with the other graves indicate that the grave was dug by hand.[...]While uncovering the grave we noticed that the earth must have contained some active substances: protective rubber gloves became destroyed.
Collected earth samples were examined by the Karol Marcinkowski University of Medical Sciences in Poznań, Department of Forensic Medicine. Caustic substances in the grave may provide evidence for experiments connected with liquidation of corpses. The special unit (Sonderkommando) under the command of SS Hauptsturmführer Herbert Lange, which in autumn 1941 in the Kazimierz Forest near Konin killed an undetermined group of victims by boiling them alive in pits filled with quicklime, was later transferred to the center in Chełmno at that time being established. It seems very likely that the attempts to liquidate the corpses with the use of lime were shifted to Chełmno. This method apparently did not prove successful with a significant number of bodies. In the cemetery thus far we have not come across another such place where the earth would contain active chemical substances.[...]
The second grave, so-called "włocławska"
[...]Situated about 20 m east of the old forest track, the grave runs parallel to it. Its current length is marked with a stone wall and equals 185 m. In order to establish its actual run, transverse probes were put up, while in inaccessible places drills were made.
On the basis of the drills made, it was possible to state that the clearing where the grave is situated was originally longer: it stretched over 45 m further south. The grave had an irregular width, ranging from about 7 m in the southeastern part, through about 10 m in the middle part, to only 4 m in the northeastern edge. While the new layout was being uncovered, the existence of burned-out objects and ashes as well as crushed human bones both burned and unburned was stated.[...]
The third grave.
Located parallel to the forest wall. On the basis of probing surveys and drills, it was stated that it reaches the forest from the south (SE), insignificantly entering its area. It passes under the forest track, which during the war most likely in this part of the clearing ran along the then forest wall, situated further on than the present one. A stone wall (about 135 meters long), which was to determine the stretch of the grave, is narrower by 2 m than the actual width of the grave. Its total length equals 174 m, width about 8 m. The contents of the grave includes sandy soil with gravel, burn waste, ash, and crushed human bones.
The fourth grave.
It is represented by a 140-metre-long wall. Located between the third and the fifth graves; its presumed location does not correspond with the actual location. The fundamental fourth grave is located between the wall of the fourth non-existent grave and covers the whole fifth grave. Its actual width equals 10 m, while its length is 182 m. It is filled with gray sandy soil mixed with inclusions of burn waste, ash and crushed bones.
The fifth grave
The last grave, or rather a line of pits filled with ashes, was not commemorated with any walls; in the 1960s it was already not discernible on the surface. On the basis of the description by Judge W. Bednarz it appears that in 1945 the pits were examined by him.
The total length of these pits equals 161 m. The stretch is made up of 11 pits, each located about 2-3 m from another. The dimensions of the pits vary from 9x7.5 m to 15.50x8.50 m. They are filled with gray soil with a significant mixture of burn waste and crushed human bones. In the southern (SE) part of the grave the bones found in the pits used to be ground; those in further parts - crushed. According to W. Bednarz, the depth of the pits was about 4 m, and the width 8-10 m. Even now the flora on the pits is more luxuriant, making this stretch more visible on the surface.