Geochemical studies of the surface of Venus by the Venera 13 and Venera 14 probes

It is noted that these probes were the first to determine the compositions of rocks near the landing site. Provinces typical of the Venusian surface, that is rolling uplands (Venera 13) and lowlands (Venera 14) were chosen for the studies. It was found that rocks near the landing site of Venera 13 have a composition similar to that of potassic alkali basalts in the earth's crust (leucite basalts and alkali trap basalts). The rocks at the Venera 14 site have a composition similar to that of oceanic tholeiites and porphyritic tuffs on earth.