Editing Tiwanaku (section)

== Site history ==
The dating of the site has been significantly refined over the last century. From 1910 to 1945, [[Arthur Posnansky]] maintained that the site was 11,000–17,000 years old<ref name = "Posnansky 1910">{{cite book | last1 = Posnansky | first1 = Arthur | year = 1910 | title = Tihuanacu e islas del Sol y de la Luna (Titicaca y Koati). | place = La Paz}}</ref><ref name = "Posnansky 1945">{{cite book | last = Posnansky | first = Arthur | year = 1945 | title = Tihuanacu, the Cradle of American Man | volume = I–II | others = Translated by James F. Sheaver | publisher = JJ Augustin | place = New York}}</ref> based on comparisons to geological eras and [[archaeoastronomy]]. Beginning in the 1970s, Carlos Ponce Sanginés proposed the site was first occupied around 1580 BC,<ref name = "Ponce Sanginés 1971">{{cite book | last = Ponce Sanginés | first = Carlos | year = 1971 | title = Tiwanaku: Espacio, Tiempo y Cultura | place = La Paz | publisher = Academia Nacional de Ciencias de Bolivia}}</ref> the site's oldest radiocarbon date. This date is still seen in some publications and museums in Bolivia. Since the 1980s, researchers have recognized this date as unreliable, leading to the consensus that the site is no older than 200 or 300 BC.<ref name = "Browman 1980">{{cite journal|last= Browman|first=David|year=1980|title = Tiwanaku expansion and economic patterns | journal = Estudios Arqueológicos|volume=5|pages=107–120}}</ref><ref name = "Janusek 2003">{{cite book | last=Janusek|first=John|year=2003|title = Tiwanaku and Its Hinterland: Archaeological and Paleoecological Investigations of an Andean Civilization, Vol. 2: Urban and Rural Archaeology | chapter = Vessels, Time, and Society: Toward a Ceramic Chronology in the Tiwanaku Heartland | editor-last = Kolata | editor-first = Alan | place = Washington, D.C. | publisher = Smithsonian | pages = 30–89}}</ref><ref name = "Stanish 2003">{{cite book | last = Stanish | first = Charles | year = 2003 | title = Ancient Titicaca | place = Los Angeles | publisher = University of California Press}}</ref> More recently, a statistical assessment of reliable radiocarbon dates estimates that the site was founded around AD 110 (50–170, 68% probability),<ref name = "Marsh2012a">{{cite journal | last1 = Marsh | first1 = Erik | year = 2012 | title = A Bayesian Re-Assessment of the Earliest Radiocarbon Dates from Tiwanaku, Bolivia | journal = Radiocarbon | volume = 54 | issue = 2 | pages = 203–218 | doi = 10.2458/azu_js_rc.v54i2.15826| bibcode = 2012Radcb..54..203M | doi-access = free }}</ref> a date supported by the lack of ceramic styles from earlier periods.<ref name = "Marsh2012b">{{cite journal | last1 = Marsh | first1 = Erik | year = 2012 | title = The Founding of Tiwanaku: Evidence from Kk'araña | journal = Ñawpa Pacha | volume = 32 | pages = 169–188 | doi = 10.1179/naw.2012.32.2.69| s2cid = 194040072 }}</ref>

Tiwanaku began its steady growth in the early centuries of the first millennium AD. From approximately 375 to 700 AD, this Andean city grew to significance. At its height, the city of Tiwanaku spanned an area of roughly 4 square kilometers (1.5 square miles) and had a population greater than 10,000 individuals. The growth of the city was due to its complex agropastoral economy, supported by trade.<ref name="FirstCities(Book)">{{cite book |last1=Andrews |first1=Anthony P. |title=First Cities |date=1995 |publisher=St. Remy Press |location=Canada |isbn=0-89599-043-1 |pages=158–160 |access-date=26 July 2022 |url=https://www.biblio.com/book/first-cities-exploring-ancient-world-andrews/d/1140635614}}</ref>

The site appeared to have collapsed around 1000 AD, however the reasoning behind this is still open to debate. Recent studies by geologist Elliott Arnold of the [[University of Pittsburgh]] have shown evidence of a greater amount of aridity in the region around the time of collapse. A drought in the region would have affected local systems of agriculture and likely played a role in the collapse of Tiwanaku.