The dynamical and population properties in the high-redshift galaxy cluster candidate LCDCS-S001, are analyzed through imaging and multi-object spectroscopy obtained with the GMOS instrument in the Gemini South Observatory. The objects were selected in an i' band cluster field image, and multi-object spectroscopic observations centered at 7500 Å were performed for 40 objects. Spectral features were successfully identified for 20 objects, and used to determine the redshift of the cluster. We found that 12 objects are cluster members and estimate a median redshift of 0.709 for this cluster. The relative velocities of the cluster members were used to estimate the projected cluster mass, which was found to be 3.54x10¹⁴ Solar masses .

Lick and Dn (4000) indices were measured and used to determine the stellar population properties of the galaxies, by means of a spectral synthesis through Bruzual & Charlote evolutive models. We found that the bulk of stellar population for the cluster members has a spectrum compatible with solar metallicity and an age between 3.0 and 7.0 Gyrs; with only one exception, the flux contribution of younger 1.0 Gyrs stars in the spectra does not exceed 25 % at 4200Å. Emission [OII] lines were detected for 4 galaxies, all of which showing a stronger contribution of young stars compared with other cluster galaxies. The equivalent width of the [OII] l3727 line was compared with Magris, Bruzual and Binette models for HII regions. We found good correspondence between our values and the theoretical predictions for solar metallicity and with star formation timescales 1.0 < t < 3.0 Gyrs.

In morphological terms we have found that spheroid map better the structure of the cluster, the disk galaxies populating preferably the peripherical regions . Local overdensities identified, one of which being part of the cluster, suggest that the clusters is undergoing a fusion processes. This hypothesis is strengthened by the identification of a radio source in 1.4 GHz characteristic of radio haloes found in cluster which undergo dynamical instabilities. Regarding the radial dependence of the measured parameters, we have found that the most massive and galaxies, and those with less mass contribution of younger stars, populate the cluster center, an effect expected in the hierarchical formation scenario.