Final answer:
The large groups of ceramic sculpture dating between 1100 and 1500 CE were excavated from Mali, specifically related to the Djenné peoples of the Inland Niger Delta region. They utilized the coil method for creating terracotta sculptures, which were then burnished for a glossy finish, demonstrating the cultural sophistication of that era.
Step-by-step explanation:
The large groups of ceramic sculpture dating between 1100 and 1500 CE that have been excavated from an inland delta area are in the modern country of Mali. This time frame and location correspond to the archaeological finds related to the Djenné peoples of the Inland Niger Delta region. One of the most significant sculptures from this era, as noted by The Metropolitan Museum of Art, is a terracotta seated figure that encapsulates the tension of anxiety and deep prayer, indicative of the sophisticated society that existed in that region during those centuries.
The region's potters used the natural resources available to them, such as the all-uvial river mud, which was abundant and ideal for creating large and detailed terracotta sculptures. They employed techniques like the coil method, and once the sculptures were nearly dry, they covered them with slip and burnished them to achieve a smooth, glossy finish. These artistic practices reflect not only the functionality but also the cultural and spiritual expressions of the society at that time.