Gangapur Formation
{{Short description|Geological formation in India}}
{{Infobox rockunit
| name = Gangapur Formation
| image =
| caption =
| type = Geological formation
| age = Early Cretaceous
| period = Cretaceous
| prilithology =
| otherlithology =
| namedfor = Gangapur Village
| namedby =
| region = Telangana
| country = India
| coordinates = {{coord|19.16|N|79.26|E|display=inline,title}}
| paleocoordinates =
| unitof =
| subunits =
| underlies =
| overlies = Unconformity with the Kota Formation
| thickness =
| extent = Pranhita-Godavari Basin
| area =
| map = {{Location map+ | India
| relief = 1
| width = 250
| float = center
| places =
{{Location map~ | India
| lat_deg = 18.9
| lon_deg = 80.0
| mark = Blue pog.svg
| marksize = 10
}}
}}
| map_caption =
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The Gangapur Formation is a geological formation in Telangana, India. The Gangapur formation is Early Cretaceous in age. It forms a part of the Pranhita–Godavari Basin and overlies the Jurassic Kota Formation. The outcrops near the Gangapur village was first described in 1881 as the Gangapur beds.King W. 1881. The geology of the Pranhita-Godavari Valley. Mem. Geol. Surv. India 18(3): 151-311. In 1969, the area was instituted as the Gangapur Formation. It was also determined that the Gangapur Formation extends from north of Nowgaon (Lat. 19°20’N; Long. 79°24’E) to the west of Gangapur (Lat. 19°16’N; Long. 79°26’E) and in the east up to Dharmaram and Paikasigudem.Kutty T. S. 1969. Some contributions to the stratigraphy of the Upper Gondwana Formations of the Pranhita-Godavari Valley, central India. J. geol. Soc. India. 10(1): 33-48. Fossils of Plants have been found in large quantities in the formation.
Stratigraphy
The Gangapur Formation was laid down sometime in the Early Cretaceous due to renewed rift activity.{{Cite journal |last=Biswas |first=S. K. |date=2003-03-01 |title=Regional tectonic framework of the Pranhita–Godavari basin, India |url=https://www.sciencedirect.com/science/article/pii/S1367912002001451 |journal=Journal of Asian Earth Sciences |series=Geology of the Pranhita-Godavari Valley, India |volume=21 |issue=6 |pages=543–551 |doi=10.1016/S1367-9120(02)00145-1 |issn=1367-9120|url-access=subscription }} The rocks of the formation are composed of coarse ferruginous sandstone interrupted with pebble bands succeeded by an alternating sequence of sandstones and mudstones or silty mudstone. Both the Gangapur Formation and the Chikiala Formation overlie the Kota formation however their exact relationships are uncertain. This uncertainty is partly due to the lack of fossils from the Chikiala Formation. It is possible that the Gangapur Formation is older than the Chikiala FormationRaiverman V., Rao M. R. & Pal D. 1985. Stratigraphy and structure of the Pranhita-Godavari Graben. Petrol. Asia J. 8(2): 174-189.Lakshminarayana G. 1996. Stratigraphy and structural framework of the Gondwana sediments in the Pranhita-Godavari Valley, Andhra Pradesh. Gondwana Nine (1), Geol. Surv. India: 311- 330. or that they are both of the same age.Rudra D. K. 1982. Upper Gondwana stratigraphy and sedimentation in the Pranhita-Godavari valley, India. Quart. Jour. Geol. Min. Metall. Soc. India 54: 56-79.{{Cite journal |date=2022-08-17 |title=Gondwana Sequence of the northern Pranhita-Godavari Valley: its stratigraphy and vertebrate faunas {{!}} Journal of Palaeosciences |url=https://www.jpsonline.co.in/index.php/jop/article/view/1582 |language=en-US}}https://www.researchgate.net/publication/269109738_GYMNOSPERM_FOSSILS_FROM_THE_GANGAPUR_FORMATION_EARLY_CRETACEOUS_OF_ADILABAD_DISTRICT_Gymnosperm_fossils_from_the_Gangapur_Formation_Early_Cretaceous_of_Adilabad_District_Telangana_India
Fossil content
Plant megafossils are common in the Gangapur Formation, dominated by the Coniferales.http://14.139.63.228:8080/pbrep/bitstream/123456789/978/1/PbV30N2_121.pdfRamakrishna H. & Muralidhar Rao G. 1986. Pterophyllum medlicottianum from the Gangapur Formation of Andhra Pradesh. Curr. Sci. 55(23): 1199-1200Ramakrishna H. & Muralidhar Rao G. 1991. Conites sripermaturensis from the Gangapur Formation, A. P. J. Swamy. Bot. Cl. 8(3&4): 113-114Muralidhar Rao G. & Ramakrishna H.1988. Torreyites sitholeyi, a new record from the Gangapur Formation of Andhra Pradesh. Curr. Sci. 57(4): 203-204Lakshminarayana G. & Kutumba Rao N. 1988. A note on the occurrence of Ptilophyllum fl ora from the Chintalapudi subbasin, Pranhita-Godavari Valley, Khammam District, Andhra Pradesh. J. geol. Soc. India 32(2): 137-142Sukh-Dev & Rajanikanth A. 1988. The Gangapur: fossil fl ora and stratigraphy. Geophytology 18(1): 1-27Rajanikanth A. 1996. Palaeobotany of Mesozoic Gondwana sediments of Pranhita-Godavari Basin. Gondwana Nine (1), Geol. Surv. India: 425-438
{{Paleobiota-key-compact}}
= Megaflora =
| class="wikitable sortable" |
| Genus
! Species ! Location ! Stratigraphic position ! Material ! Notes ! Images |
|---|
| style="background:#D1FFCF;" rowspan = "3" |Taeniopteris
|style="background:#D1FFCF;" | T. kutchensis |style="background:#D1FFCF;" | Ralpet, Rampur and Peddavagu. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" | Leaves. |style="background:#D1FFCF;" | Cycad also known from the Bhuj Formation. |style="background:#D1FFCF;" | |
| style="background:#D1FFCF;" |T. spatulata
|style="background:#D1FFCF;" |Rampur, Butarmal Nala and Peddavagu. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" | Leaves |style="background:#D1FFCF;" |Cycad also known from the Rajmahal Traps.{{Cite journal |date=2023-12-06 |title=Cycadophytic leaves from Jurassic - Lower Cretaceous rocks of India {{!}} Journal of Palaeosciences |url=https://jpsonline.co.in/index.php/jop/article/view/1416 |language=en-US}} |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" |T. sp.
|style="background:#D1FFCF;" |Rampur, Nowgaon and Peddavagu. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" | Leaves |style="background:#D1FFCF;" |Cycad similar to T.sp from Antarctica. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | Cycadites
|style="background:#D1FFCF;" |C.sp. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" | |style="background:#D1FFCF;" | |style="background:#D1FFCF;" | Cycad. |style="background:#D1FFCF;" | |
| style="background:#D1FFCF;" rowspan = "5"|Ptilophyllum
|style="background:#D1FFCF;" | P. cutchense |style="background:#D1FFCF;" | Rampur and Nowgaon. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" |Leaves. |style="background:#D1FFCF;"| Bennettitales. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | P. acutifolium
|style="background:#D1FFCF;" | Rampur and Peddavagu. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" |Leaves. |style="background:#D1FFCF;"| Bennettitales. Resembles P. acutifolium from the Raghavapuram Formation. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | P. rarinervisBose M. N. & Kasat M. L. 1972. The genus Ptilophyllum in India. Palaeobotanist 19(2): 115-145.
https://eurekamag.com/research/006/869/006869186.php
|style="background:#D1FFCF;" | Butarmal Nala. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" |Leaves. |style="background:#D1FFCF;"| Bennettitales. Originally referred to as Otozamites rarinervis.Feistmantel O. 1879. The fossil fl ora of the Upper Gondwanas. Outliers on the Madras Coast. Mem. Geol. Surv. India, Palaeont. Indica, Ser.2, 1(4):191-224 |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | cf. P. distans
|style="background:#D1FFCF;" | Butarmal Nala. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" |Leaves. |style="background:#D1FFCF;"| Bennettitales. Resembles P. distans. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | P. distans
|style="background:#D1FFCF;" | Butarmal Nala. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" |Leaves. |style="background:#D1FFCF;"| Bennettitales. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | ?Anomozamites
|style="background:#D1FFCF;" | ?A. sp |style="background:#D1FFCF;" | Nowgaon. |style="background:#D1FFCF;" | |style="background:#D1FFCF;"| Leaves. |style="background:#D1FFCF;"| Bennettitales. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" rowspan = "6"|Elatocladus
|style="background:#D1FFCF;" | E. confertus |style="background:#D1FFCF;" | Ralpet, Rampur, Nowgaon, Butarmal Nala and Peddavagu. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" |Leaves. |style="background:#D1FFCF;"| Coniferales. Very common in the Gangapur Formation. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | E. sehoraensis
|style="background:#D1FFCF;" | Ralpet and Butarmal Nala. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" |Leaves. |style="background:#D1FFCF;"| Coniferales. Also known from the Jabalpur Formation. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | cf. E. bosei
|style="background:#D1FFCF;" | Ralpet and Butarmal Nala. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" |Leaves. |style="background:#D1FFCF;"| Coniferales. Comparable to E. bosei of the Jabalpur Formation. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | E. andhrensis
|style="background:#D1FFCF;" | Ralpet, Nowgaon and Peddavagu. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" |Leaves. |style="background:#D1FFCF;"| Coniferales. Specimens belonging to this species were also registered as E. confertus and E. heterophylla.Pal A. K., Datta P. M., Basu P. K., Shome S. & Ghosh S. C. 1988. Cone bearing shoots of Elatocladus Halle from Gangapur Formation (Lower Cretaceous) of Andhra Pradesh, India. Curr. Sci. 57(3): 141-142. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | E. sp
|style="background:#D1FFCF;" | Nowgaon and Peddavagu. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" |Leaves. |style="background:#D1FFCF;"| Coniferales. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | E. kingianus
|style="background:#D1FFCF;" | Cave Temple. |style="background:#D1FFCF;" | |style="background:#D1FFCF;" |Leaves. |style="background:#D1FFCF;"| Coniferales. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" rowspan = "2" | Pagiophyllum
|style="background:#D1FFCF;" | P. marwarensis |style="background:#D1FFCF;" | Rampur. |style="background:#D1FFCF;" | |style="background:#D1FFCF;"| Leaves. |style="background:#D1FFCF;"| Coniferales. Also known from the Jabalpur Formation. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | P. rewaensis
|style="background:#D1FFCF;" | Peddavagu. |style="background:#D1FFCF;" | |style="background:#D1FFCF;"| Leaves. |style="background:#D1FFCF;"| Coniferales. Also known from the Jabalpur Formation. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | ?Cladophlebis
|style="background:#D1FFCF;" | ?C. sp |style="background:#D1FFCF;" | Peddavagu. |style="background:#D1FFCF;" | |style="background:#D1FFCF;"| Leaves. |style="background:#D1FFCF;"| Fern. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | Gleichenia
|style="background:#D1FFCF;" | G. nordenskioildii |style="background:#D1FFCF;" | Nowgaon. |style="background:#D1FFCF;" | |style="background:#D1FFCF;"| Leaves. |style="background:#D1FFCF;"| Fern. |style="background:#D1FFCF;"| |
| style="background:#D1FFCF;" | ?Gleichenia
|style="background:#D1FFCF;" | G. sp |style="background:#D1FFCF;" | Nowgaon. |style="background:#D1FFCF;" | |style="background:#D1FFCF;"| Leaves. |style="background:#D1FFCF;"| Fern. |style="background:#D1FFCF;"| |
| rowspan="2" style="background:#D1FFCF;" | Coniferocaulon
|style="background:#D1FFCF;" | C. sp. | rowspan="2" style="background:#D1FFCF;" | Peddavagu and quarry north of the Cave Temple. | rowspan="2" style="background:#D1FFCF;" | | rowspan="2" style="background:#D1FFCF;" | Leaves. | rowspan="2" style="background:#D1FFCF;" | Coniferales. Also known from the Jabalpur Formation. | rowspan="2" style="background:#D1FFCF;" | |
| style="background:#D1FFCF;"|cf. C. rajmahalense |