Complex sentence: She then ran off with another man and in late 1937, alone in Oaxaca, Lowry entered another period of dark alcoholic excess, culminating in his being deported from the country.
Split into simpler sentences: She then ran off with another man and in late 1937. Alone in Oaxaca, Lowry entered another period of dark alcoholic excess, culminating in his being deported from the country.