Complex sentence: Afanasevo culture, 3500--2500 BC, an archaeological culture of the late copper and early bronze age approximately centered in the valley of the Minusa River, a tributary of the upper Yenisei River, in the Minusinsky district of the Krasnoyarsk Krai region of Russia.
Split into simpler sentences: Afanasevo culture, 3500--2500 BC, an archaeological culture of the late copper and early bronze age. It was approximately centered in the valley of the Minusa River, a tributary of the upper Yenisei River, in the Minusinsky district of the Krasnoyarsk Krai region of Russia.