Who are these Gaṇas?
The Rig Veda sings:
“Oh Courageous (तवेषं) band/group (गणं) of Maruts“ RV5.58.
So Maruts are called Ganas. गणं (gana) means group, and these groups and their professions are explained in detail in Śrī Rudram of Kṛṣṇa Yajur Veda Taittirīya Saṃhitā 4.5. The leader of these groups is called Ganapati (gana+pati), meaning lord/abode of all groups.
Is there any detailed description available?
The Rig Veda also addresses the Maruts as vidatheṣu ā-bhuvaḥ, meaning born in knowledge, and brahmānaspathim, meaning lord/abode of knowledge RV1.38.13. Brahmānaspathim is a very unique title in the Vedas assigned to a separate class of Divinities. Sri Aurobindo defines brahmāna as the Vedic Aksharas (word) and among all Aksharas “अ/a” is considered the foremost, hence AUM begins with अ. In Śrīmad Bhagavādgita Śrī Kṛṣṇa says “Among words I am the word अ“.
Panini, the author of Sanskrit Grammar says, Maruts are Akshara of Varnamala (an eternal string of sounds), and Sukla Yajur Veda Śatarudrīya explains how Rudra and Gayatri Akshara emerged from Yagna. Sri Aurobindo includes both Brihaspati and Brahmā as brahmānaspathim. Similarly, T.V. Kapali Sastry, a renowned student of Sri Aurobindo and Vedic commentator, says Ganapati – “Lord of all Ganas/Maruts” – is that brahmānaspati. Interestingly, the Rig Veda titles Viṣṇu as Evaya Marut RV5.87, meaning the “fastest Marut” who leads the Maruts into battle. This is a very interesting linkage of titles, like puzzles that fit together. Though Rudra Ganas are mentioned along with their leader, we are yet to find a reference of one with an Elephant face. Viṣṇu being Evaya Marut also declares Himself to be ŚipiViṣṭa (शिपिविष्ट) RV7.100.6 meaning the rays which permeate, this title is given to both Viṣṇu and Rudra TS4.5.5. Aitareya Brahmāṇa 1.30 states that Viṣṇu is the leader of the Maruts and both Ashivns and Varuna who themselves being Rudras follow His lead.
Please refer to original sources, like Puranic verses along with verse numbers?
There is no original source other than the Vedas, Upanishads, and Itihasas. The above and the following references are original.
तम उ नूनं तविषीमन्तम एषां सतुषे गणम मारुतं नव्यसीनाम |य आश्वश्वा अमवद
वहन्त उतेशिरे अम्र्तस्य सवराजः || तवेषं गणं तवसं खादिहस्तं धुनिव्रतम
मायिनं दातिवारम |मयोभुवो ये अमिता महित्वा वन्दस्व विप्र तुविराधसो नॄन
Indeed we praise (एषां) thy mighty (तविषी) gang (गणम) of Maruts today
(नव्यसी)| Oh fierce (अमवद) racers of horses and chariots (आश्वश्वा)
like the wind (वहन्त), bringing your containers filled with elixir of
immortality (उतेशिरे अम्र्तस्य), you are dependent on none, self
ruling (सवराजः)|| Oh courageous (तवेषं) band/group (गणं) of Maruts,
adorned with bracelets/rings (खादिहस्तं), cometh with roaring sounds
(धुनिव्रतम) of victory, bestower (दातिवारम) of all magical gifts
(मायिनं) | We sing to the brilliance, like fire (मयोभुवो) adorned with
infinite might (अमिता महित्वा). We praise and worship (वन्दस्व), oh
ever willing and passionate ones (विप्र) with roaring sounds
(तुविराधसो). We follow you, oh leader (नॄन).
Rig Veda 5.58
The description of their power and weapons used by them, and their residence?
The Vedas sing about Rudras/Maruts as infinite in numbers and immortal, free-spirited, mountain-dwelling2 (of Mūjavant/Girisha), fierce warriors, vehement and hero clan VS16.8-11. They hold the most powerful weapons VS16.14 including the famous bow called the PinakaTS4.5.5. They possessed tools, and riches, unparalleled to any3. Hymns proclaim that they are indestructible “ānirhatebhyo” KY4.5.9 and formidable who controls the army and a terrifying ruler who sits in the void of men AV18.1.40 as He is the vital force Prana BrhdUpa3.9.4, and there are none mightier than Rudras4 as they possess infinite-strength/omnipotent which the Vedas call “ananta-śuṣmāḥ” RV1.64.10. Rudras (rudrébhis or rudrésu) are the only Divinities in the Vedas to possess a multitude of precise and powerful weapons. Atharva Veda speaks of Rudra’s golden bows and weapons flying abroad like guided missiles in the direction he desires AV11.2.12. The only other Divinity who comes close to possessing multiple weapons is Indra; He too has a weapon common to Rudra, which is the lightning (Asani). These hymns define Rudras and Maruts as Earth-shaking clans feared by all lokas as they could create fires, bring rain (nourishment and lords of food RV2.1.6), hunts like predators, attack thousands, and kill in hundreds AV11.2.12 causes lightning and thunder5, and make rain in deserts RV1.38.7. Hence he is called the Tempest God, and also has the title Aśani given to Rudra in Brahmāṇa-1 of Vājasaneyi Saṃhitā 18.104.22.168.
Who are the father and mother of these Ganas?
Rudra is the father of Maruts “idam pitre marutām” RV1.114,2.33,1.64. And Rudra is always surrounded by Maruts who are generally denoted as Rudras themselvesRV8.63.12. These Maruts are, on occasions, said to be the children of Pṛśni “The Vedic Cow of Knowledge”. Hence, Maruts are addressed with three profound titles – “vidatheṣu ā-bhuvaḥ” meaning “born in knowledge”, second “mahiṣāsaḥ māyinaḥ:citra-bhānavaḥ” meaning “the makers of māyā and of clear vision/light”, finally “pra-cetasaḥ viśva-vedasaḥ” meaning “conscious & omniscient” RV1.64.6-10. These three titles are not to be taken lightly. In the realm of the Vedas, Soma, Vāk, and Pṛśni are three abstract concepts that secretly control the entirety of Vedic essence. Let us take a quick glance.
गौर्धयति मरुतां श्रवस्युर्माता मघोनाम् युक्ता वह्नी रथानाम् | यस्या
देवा उपस्थे॑ व्रता विश्वे धारयन्ते सूर्यामासा दृशे कम् || 8.94.1-2 The
Cow (Pṛśni is the cow of knowledge, and milk/Soma is wisdom/knowledge
of immortality) (गौ + र्धयति dhā+yati), with Maruts (मरुतां) as sons
of a mother who deserves our highest honor (श्रवस्यु + माता) and who
is rich/abundant in knowledge and wisdom ( मघोनाम् = मघ+वन्- म्),
harnesses/yokes them (the vehicles) to move Creation forward (वह्नी –
रथा-नाम्)| In You/Pṛśni ( यस्या 3rd person), reside/dwell (उपस्थे) all
Divinities/Vedic Devas (देवा) and have their eternal (विश्वे) virtuous
function (व्रता) relied upon and borne by you (धारयन्ते); the Sun
(सूर्या) and the Months/Moon (मासा) witness their (दृशे) role/actions
(कम्) Please note: In the Vedas (same as Śrīmad Bhagavādgita), the cow
represents mother of knowledge, cow’s milk represents wisdom and
essence, the bull represents might and lordship hence the title
“Bablusãye bi vyadhibe”TS4.5.5, horses represent speed and momentum
and energy, chariots/vehicles are the creation/body itself. वह्नी =
वह् means vehicle and वह्नी -रथा means wagons attached to the chariot.
Rig Veda 8.94.1-2
Pṛśni is also the name of the wife of Prajāpati, which is also correct as Prajāpati is the Yajamana (the one performing the Yajñá), but we will soon explore the overlap of Prajāpati and Rudra. Pṛśni is also the name of the wife of one among the Saptarishi (the 7 primordial divine sages). Maruts are also said to be the children of Rodasī (consort of Rudra) and the same hymn distinctly addresses Rudra as their father RV5.57
Source 1: LINK
Source 2: LINK