Wow that is really interesting. Not a medal but a great recognition for his service on that day.
Translation and summary at the bottom by ChatGpt:
On the night of October 2–3, a patrol operation was carried out by the 5th Company, consisting of 24 men under the command of Lt. Eckardt.
As the various detachments advanced, Cpl. Mierzwa, with four men, came upon a still-unoccupied but well-fortified English position and surrounded it in a semicircle. Soon afterward the English approached; when they reached the “los” [signal/position] of Cpl. Mierzwa, they threw hand grenades, and the patrol jumped into the trenches. The English resisted desperately, during which Mierzwa received a bayonet thrust in the body. Soon all five Englishmen lay dead in the trench.
As Lt. Eckardt of the patrol hurried to Mierzwa's aid, the English attacked from all sides. Lt. Eckardt then withdrew as ordered, continuously pursuing and keeping the English at bay.
At the same time, a strong English attack was launched against our position, which was followed by the conclusion that the English had intended an operation against us, for which we had been forewarned.
Cpl. Mierzwa, who was decorated the following day with the E.K. I. Kl. (Iron Cross, 1st Class), succumbed to his wounds. Lt. Eckardt also demonstrated great skill and bravery during this operation.
“The document is describing a German patrol action against an English position during World War I, and specifically commends Cpl. Mierzwa and Lt. Eckardt for their actions.”