Field Report of New Campus Jamshoro
INTRODUCTION:
The studied area around
The folding of the area is very gentle and dipping at 2-4 degree due to mild tectonic movement.
PURPOSE AND SCOPE:
The main purpose of the report is to carryout the Geological mapping and to describe the straitigraphy, lithology and topographic features for further research to confirm the age of the formation and examine the economic importance of the area.
LOCATION AND ACCESSIBILITY:
The
GEOMORPHOLOGY:
TOPOGRAPHY:
Generally relief of the assigned area is low and constitute elongated ridges and subsequent valleys which are major topographic features of the area. The thickness of Laki formation in the assigned area is 28 meters. The major drainage pattern of the area is redial and dendritic, controlled by structures and nature of the rock units exposed. Soil is clayey and alluvial in nature.
VEGETATION:
Vegetation is not much due to lack of sufficient water and soil cover, which mainly influence the vegetal growth in the assigned area. In seasonal rainfall the area becomes green by local vegetation.
LAKI FORMATION:
The term “Laki series” was proposed by Noetling (1903) for the lower part of the Blan Ford’s “Kirthar series” (1876). Later Hunting Survey Corporation (1961) redefined the unit as “Laki group”. In the present report it is named as Laki formation which also represents the “Sui Main Limestone” of Tainsh et.al, (1959).
Nuttal (1925) subdivided this formation in to Laki limestone, Meting Shale, Meting limestone and Basal Laki Laterite (Sonahri beds) members. These members are highly fossiliferous.
In (1920-21) field season Nuttal conducted and Sathana visited some isolated areas of Laki Shah Saddar about 120 km away from assigned area. Nuttal (1923) again visited the area of Laki Shah Saddar while carrying his Geological reconnaissance work in lower Sindh. He examined section work in Laki range and described the above members in the Laki formation.
Contact relationship: The lower contact of Laki formation is discomforable with Lakhra formation which is marked by the Sonahri beds, whereas the upper contact is conformable to Kirthar formation (late Eocene).
Age: On the basis of various invertebrate fossils the Hunting Surveys Corporation assigned the age of the Laki formation Early Eocene.
Thickness: The thickness of the Laki formation in the assigned area is 28 meters.
BASAL LAKI LATERITE:
The basal Laki Laterite (Sonahri beds) is the deposits of early Eocene and is poorly exposed in the assigned area. It mainly consists of highly ferrogenious lateritic clay and shale of variegated colors, mainly rusty brown. Commonly it is soft and sugary. The lanticular beds of variegated ferrogenious sandstone and white calcarious sandstone are common.
Contact relationship: The lower contact of basal laki Laterite is discomforable to Lakhra formation whereas upper contact is conformable to Meting limestone member.
Fossils: Mostly it is lacking in fossils.
Age: The age of Basal Laki Laterite is E.Eocene which is assigned by Nuttal (1925).
Thickness: Thickness of this member is 1.5 meters.
METING LIMESTONE:
The name Meting limestone has been from the area where it is very well exposed in Meting village near Jhirk, district Thatta.
Meting limestone member mainly consist of hard, compact, massive, cherty limestone.
Contact relationship: The upper contact is conformable to meting shale member whereas the lower contact is also conformable to Basal Laki Laterite member.
Fossils: The characteristic fossils are Folusculina globosa, Alvulina oblange. These are species of Forams.
Age: Various species of Foraminifera such as Assilina groulosa, Folusculina oblange etc, indicate the age this member as Early Eocene (Nuttal 1925).
METING SHALE:
The Meting shale member is grayish brown in colour and is mainly composed of gypsiferous shale and soft thin bedded ferrogenious limestone but at places the reddish brown clay is noted as the major constituent of Meting Shale. At some places the arenaceous limestone is interbedded.
Contact relationship: The upper contact is conformable with Laki limestone member whereas the lower contact is also conformable with meting limestone.
Fossils: In this member the fossils are not in sufficient amount, but some type of Brachiopodes and Echinoids are present.