I think 'development' may be a more accurate description than 'discovery' for the production and occupations of the Chinese during the ancient Shang and Zhou dynasties. In these times, bronze was in use for chariots, armour as well as jewellry.
Iron may have been a discovery, for it came into use right near the end of this period. There was a form of writing in existence but it cannot be said for how long it had been used, or for how many in the population.
Inscriptions have been found on bones and bronze objects. Cultural and military output blossomed during this period as well as religious thought and systems of working and recording.
Some of the important discoveries made during the Shang and Zhou dynasty include: Bronze work: the Shang dynasty industrialized bronze work, they made exquisite bronze vessels and weapons as it reached the heights of China’s Bronze Age. Several workshops were built outside cities and equipped with iron tools, furnace, and melds. Workers were employed to shape bronze into jewellery, ceremonial devices, ornaments, dishes, weapons, helmets and utensils.
Military technology, calendar, writing and religion were other discoveries of the Shang dynasty. Some of the achievements of the Zhou dynasty include: Artistry: Iron and bronze were used to create new and impressive piece during the Zhou period. Technology and warfare: the military men improved the design of the crossbow. The trebuchet was invented at the time too. New innovations in architecture, cultural innovations, agricultural and commerce were improved during the Zhou dynasty.