The Kandreho Formation is an
Early Jurassic (middle or late
Toarcian)
geological formation of the
Mahajanga Basin of
Madagascar. The
marl
Marl is an earthy material rich in carbonate minerals, clays, and silt. When hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae.
Marl makes up the lower part o ...
y
limestones of the formation were deposited in a subtidal
lagoonal
environment. The formation overlies the ''
Bouleiceras'' and ''
Spiriferina
''Spiriferina'' is an extinct genus of brachiopods that lived from the Late Silurian to the Middle Jurassic in Asia, Europe, North America, South America, and New Zealand.[Marrat Formation
Maarat al-Numan ( ar, مَعَرَّةُ النُّعْمَانِ, Maʿarrat an-Nuʿmān), also known as al-Ma'arra, is a city in northwestern Syria, south of Idlib and north of Hama, with a population of about 58,008 before the Civil War (2004 ...]
of
Saudi Arabia. Fossils of the marine crocodylian ''
Andrianavoay
''Andrianavoay'' (meaning "noble crocodile" in Malagasy) is an extinct genus of teleosauroid from the Bathonian (in the Middle Jurassic) Kandreho Formation of Madagascar.
The type species, ''A. baroni'', was originally named "''Steneosaurus
...
'' (originally classed as a species of ''
Steneosaurus'') as well as
bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...
s and the
ammonite
Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...
''
Nejdia'' have been found in the formation.
Behazonaty, SW of the basin of the Kelifely
at Fossilworks
Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database
The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...
.org[Buffetaut et al., 1981, p.314] The name Kandreho Formation was proposed by Geiger in 2004.[Geiger, 2004, p.125]
Gallery
Steneosaurus_NT_small.jpg, Reconstruction of '' Macrospondylus'', a close relative of ''Andrianavoay''
See also
* List of fossiliferous stratigraphic units in Madagascar
Several fossiliferous stratigraphic units in Madagascar have provided fossils, most notably the Maastrichtian Maevarano Formation and the Jurassic Isalo III Formation. The oldest fossil-bearing formations date to ages before the break-up o ...
* Geology of Madagascar
* Isalo III Formation
* Bemaraha Formation
The Bemaraha Formation is a Middle Jurassic (early Bajocian to early Bathonian) geological formation of the Morondava Basin of Madagascar. The lime mudstones, grainstones and limestones of the formation were deposited in lagoonal and ree ...
* Toarcian turnover
* Toarcian formations
** Marne di Monte Serrone, Italy
** Calcare di Sogno
The Calcare di Sogno ("Sogno Limestone"; also known as the Sogno Formation) is a geological formation in Italy, dated to roughly between 183-181 million years ago and covering the Toarcian stages of the Jurassic Period in the Mesozoic Era.CARTA GE ...
, Italy
** Sachrang Formation
The Posidonia Shale (german: Posidonienschiefer, also called Schistes Bitumineux in Luxembourg) geologically known as the Sachrang Formation, is an Early Jurassic (Toarcian) geological formation of southwestern and northeast Germany, northern Swit ...
, Austria
** Posidonia Shale
The Posidonia Shale (german: Posidonienschiefer, also called Schistes Bitumineux in Luxembourg) geologically known as the Sachrang Formation, is an Early Jurassic (Toarcian) geological formation of southwestern and northeast Germany, northern Swit ...
, Lagerstätte in Germany
** Ciechocinek Formation, Germany and Poland
** Krempachy Marl Formation
The Krempachy Marl Formation is a geological formation in Poland and Slovakia, dating to about 179 million years ago, and covering the middle Toarcian stage of the Jurassic Period.Birkenmajer, K. 1977. Jurassic and Cretaceous lithostratigraphic ...
, Poland and Slovakia
** Lava Formation
The Lava Formation is a Mesozoic geologic formation in Lithuania and Kaliningrad, being either the sister or the same unit as the Ciechocinek Formation. It represents the outcrop of Lower Toarcian layers in the Baltic Syncline and in the Lithua ...
, Lithuania
** Azilal Group
The Azilal Formation (historically Toundute Continental Series and Wazzant Formation)Known wholly in the past by the current sub-unit terms ''Toundute Continental Series'' and ''The Wazzant Formation'' is a geological unit in the Azilal and Ouarz ...
, North Africa
** Whitby Mudstone, England
** Fernie Formation, Alberta and British Columbia
*** Poker Chip Shale
** Whiteaves Formation, British Columbia
** Navajo Sandstone, Utah
** Los Molles Formation, Argentina
** Mawson Formation, Antarctica
** Kota Formation, India
** Cattamarra Coal Measures, Australia
References
Bibliography
*
* {{cite LSA , last=Geiger , first=Markus , year=2004 , title=Sedimentary and stratal patterns in Jurassic successions of western Madagascar - Facies, stratigraphy, and architecture of Gondwana breakup and drift sequences (PhD thesis) , url=http://doc.rero.ch/record/203076/files/PAL_E3919.pdf , publisher= Universität Bremen , pages=1–179 , accessdate=2018-08-30
Geologic formations of Madagascar
Jurassic System of Africa
Early Jurassic Africa
Jurassic Madagascar
Toarcian Stage
Limestone formations
Lagoonal deposits
Paleontology in Madagascar
Formations