Cuddalore Fm
Type Locality and Naming
Outcrop:
Lithology and Thickness
Sandstone – nearshore equivalent of Tittacheri Fm in the basin. In Pondicherry area: "The Cuddalore Formation consists of ferruginous arkosic sandstone associated with clay and gravel beds. The sedimentary structures viz., planar cross bedding, small scale herringbone cross bedding, cross lamination and ripple drift lamination are well developed and the thickness of formation is about 150 m." (Shyam N. Mude et al., 2020, Jour. Indian Assoc. Sedim. 37:115-130).
[Figure 1: Generalized Stratigraphy and Petroleum System of Cauvery Basin (from dghindia.gov.in)]
[Figure 2: Generalized Stratigraphy of Cauvery Basin (Provided by A. Nallapa Reddy & R. Nagendra)]
Relationships and Distribution
Lower contact
Unconformable with different onshore formations (Karasur Fm in Pondicherry area; Aladi Fm in Vriddhachalam area, Kallamedu Fm in Ariyalur area); but conformable offshore with Madanam Fm in Ariyalur-Pondicherry sub-basin and Madanam-Kumbakonam high)
Upper contact
Alluvial or Pleistocene.
Regional extent
Entire outcrop region and much of offshore. But grades into clayey sandstone of Tittacheri Fm offshore.
GeoJSON
Fossils
Age
Depositional setting
Inner neritic.