The purpose of this research is to investigate the folding and shortening within the northern Kerman coalfield area, which is part of the tectonically active regions due to the structural diversity of the Earth's crust. The main deformation in this area has been influenced by the stresses resulting from compression and extension in central Iran, resulting in folding and faulting. The Koohbanan fault is one of the most significant structures in this region, causing various structural changes in the northern Kerman coalfield during the Quaternary period. By examining folding and analyzing the shortening resulting from the faults in the cross-sectional domain, which exhibit a syncline arrangement with their axes inclined relative to the main cross-sectional axis, we can attribute it to the compressional stress induced by the right-lateral movement of the Koohbanan fault.

Around 40% of the foldings are the result of compressional stress during the Alpine tectonic events. Based on the conducted studies, evidence suggests that the folds in the region are compressed from both sides towards the center, forming new folds at both ends. The complete sequence of pre-folding and post-folding flexural structures, notably faults, suggests that except for the Koohbanan and Tarz faults, which played a significant role in the formation of the northern Kerman coalfield basin and existed prior to folding, the remaining faults in the region have developed after the formation of the folds. This implies that most of these faults are the result of folding-related stress, with their formation occurring post-folding.

In conclusion, this research delves into the dynamics of folding and shortening in the northern Kerman coalfield area. The study highlights the interplay of tectonic forces, particularly compressional stresses, in shaping the geological features of the region. The analysis of faulting and folding provides insights into the tectonic history of the area and sheds light on the complexities of structural deformation in response to the broader tectonic context.

The studied area is, in fact, the northern part of the Kerman coalfield region, known as the Kerman Coal Basin (Technosport 1969 report). The Kerman Coal Basin is situated in the southeastern portion of the Kerman-Baft synclinorium. This tectono-sedimentary region is bordered by the Urmia-Dokhtar volcanic zone to the south, the Ravar-Kalmardeh heights to the north, the Bafq-Saghend heights to the northwest, and the Lekrkouh heights to the east and southeast. The mentioned synclinorium is bounded by the Koohbanan fault to the southwest and the Baft-Tarz fault to the northeast.

The Kerman-Baft synclinorium consists of various structures with distinct lithological characteristics and different formation histories. These are elaborated below:

The first litho-structural unit pertains to the deformed arkosic sandstones and quartz arenites of Cambrian origin, belonging to the Iran-Arabian platform. These rocks have undergone significant deformation during the Cretaceous tectonic phase of the Katangian Orogeny. The outcrop of this unit is also observable beyond the coal basin area.

The second litho-structural unit encompasses a thick sequence of Upper Permian to Upper Jurassic deposits, which are separated from their underlying and overlying units by pronounced unconformities with steep angular discordance.

The Kerman-Baft synclinorium is geologically characterized by these diverse litho-structural units, each with its own unique sedimentary and tectonic history. The synclinorium's location within the larger tectonic context, bounded by significant faults and surrounded by different geological features, plays a crucial role in shaping its geological evolution and landscape.
By examining the style of faulting within the designated area, several points can be inferred regarding these matters, as follows:

From the assessment of the degree of closure in folds, it can be deduced that Naybandi Feizabad, Hamkar, and Baghpahn folds are, respectively, the most tightly compressed folds, situated predominantly in the northern and northeastern parts of the region. If we consider the degree of compression as indicative of the timing of deformation, looking at Figures 1 and 2, it becomes evident that the initial signs of folding occurred in the eastern portion of the basin. Subsequently, the folding progressed from the margins towards the center of the basin. This initial deformation initially impacted the northern part of the basin and gradually progressed towards the southeastern sections over time.

The classification of folds based on their apparent ratios is closely related to the degree of compression. More compressed folds correspond to taller folds, while less compressed folds are associated with shorter folds.

By analyzing the values of 'b' related to the folds, it is apparent that they mostly lie between angular to sharp-angled folds. However, a notable point is that the value of 'b' is directly related to the magnitude of the fold's effect. Smaller folds have lower 'b' values (steep and angular folds), while larger folds possess higher 'b' values (semi-angular and semi-circular folds).

Regarding the orientation perpendicular to the axis of Bagh Pahn, Bagh Tappeh, Hamkar, and Feizabad folds, it can be stated that the compression of the folds occurs from both sides towards the center. Another observation is that the wider angle between the two limbs of the Moryn and Mine 12 folds at the Heshooni narrows suggests the formation of new folds with a similar mechanism at both ends. These observations offer a complete representation of a folded belt, showcasing the formation of folds from initial stages to compression and refolding within a chronological sequence.

Determining the synchronicity or asynchronicity of ductile and brittle tectonic events poses one of the most challenging aspects of structural analysis. For the studied area, this can only be deduced to some extent through the truncation of folds by faults. However, a full sequence of pre-folding and post-folding flexural structures can only be established through absolute age determinations. Nevertheless, due to the truncation of most fold limbs by faults in the region, it can cautiously be suggested that, except for the Koohbanan and Tarz faults, which played a significant role in the formation of the coalfield basin and existed prior to folding, the other faults in the area developed after the formation of the folds. In conclusion, this has given rise to the following structural pattern.