Abstract Detail

Plants at the Cretaceous-Paleogene boundary

Manchester, Steven [1], Smith, Selena [2], Kapgate, Dashrath [3], Matsunaga, Kelly [4], Samant, Bandana [5].

Hypotheses of floristic change in fruits and seeds across the K-Pg boundary in India.

Most of the paleobotanically rich chert exposures of the Deccan Intertrappean beds of central India are situated so close to the Cretaceous-Tertiary boundary that it has been a challenge to obtain sufficiently precise radiometric data to ascertain which side of the boundary is represented. Most of the sites with well preserved fruits and seeds occur in two main regions: 1) along the eastern side of the main Deccan Volcanic Province in and around the city of Nagpur (and extending 150 km northwest and 100 km south-southeast), and 2) the Mandla lobe traps, with localities scattered over a distance of approximately 200 km from Chhindwara to Shapura. A relatively uniform megafossil flora, with several shared taxa, is represented among most chert sites of region 1 (Shibla, Takli, Ambabagholi, Murai Patan, Bada Bhendalya), and some in the western part of region 2 (Singpur, Mohgaonkalan and Keria). Palynological data are interpreted to indicate a late Maastrichtian age for these sites. On the other hand, paleobotanical sites to the north and east of Mohgaonkalan in region 2 (e.g., Dhangaon, Ghughua, Parapani, Palasunder, Umaria), occur among traps that appear to be Paleocene based on radiometric dates presented by J.P. Shrivastava, Duncan and Kashyap. The presumed Maastrichtian flora includes the following key taxa: Arecoidocarpon, Baccatocarpon, Enigmocarpon, Sahnipushpam, Graminocarpon, “Musa”cardiospermum, Pantocarpon, Viracarpon. The presumed Paleocene flora, although rich in silicified woods, includes fewer fruit-bearing cherts. Nevertheless, these floras are noteworthy in the presence of palm friuts, including Arecoidocarpon (shared with the older floras), and the apparent new arrivals, Cocos and Palmocarpon drypetioides. Current work is focused on improved characterization of the Maastrichtian carpoflora, including rarer locally restricted, as well as more widespread taxa, with combined information from nano-CT scan imagery and serial peels.

1 - Florida Museum Of Natural History, Po Box 117800, Gainesville, FL, 32611, United States
2 - Department Of Earth & Environmental Sciences, 1100 North University Avenue, 2534 CC Little Building, Ann Arbor, MI, 48109, United States
3 - JM Patel College, Bhandara, MS, India
4 - University Of Michigan, Earth And Environmental Sciences, 1100 N University Ave, 2534 CC Little Bldg, Ann Arbor, MI, 48109, United States
5 - Rashtrasant Tukadoji Maharaj Nagpur University, Postgraduate Department of Geology, Nagpur, 440001, India

Keywords:
Tertiary.

Presentation Type: Colloquium Presentations
Session: C01, Plants at the Cretaceous-Paleogene boundary
Location: 101/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 11:15 AM
Number: C01010
Abstract ID:949
Candidate for Awards:None